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* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v4 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index f8c4dada7c9..72c8aa7650b 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -257,6 +258,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 47ce61e5093..5e509153656 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -285,9 +285,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 0fdbaf79780..d78633cae44 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -510,6 +511,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--jg9kqX3osLGO+8A7
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v5 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
---
src/backend/access/transam/varsup.c | 4 ++++
src/backend/utils/activity/pgstat_backend.c | 2 ++
src/include/pgstat.h | 2 ++
3 files changed, 8 insertions(+)
43.8% src/backend/access/transam/
36.6% src/backend/utils/activity/
19.4% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 1441a051773..fe625d00f7d 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -24,6 +24,7 @@
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "utils/lsyscache.h"
+#include "utils/pgstat_internal.h"
#include "utils/syscache.h"
@@ -261,6 +262,9 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ PendingBackendStats.pending_xid_count++;
+ backend_has_xactstats = true;
+ pgstat_report_fixed = true;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 42bfb9cd38f..32ee48eab51 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -287,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += PendingBackendStats.pending_xid_count;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ PendingBackendStats.pending_xid_count = 0;
backend_has_xactstats = false;
}
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5d73c4dfbcf..780ca4b3ac0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -525,6 +525,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -543,6 +544,7 @@ typedef struct PgStat_BackendPending
*/
PgStat_Counter pending_xact_commit;
PgStat_Counter pending_xact_rollback;
+ PgStat_Counter pending_xid_count;
} PgStat_BackendPending;
/*
--
2.34.1
--uN5gGi2rtCNSVbpC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0003-Adding-the-pg_stat_backend_transaction-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v3 2/3] Adding XID generation count per backend
@ 2025-08-08 15:58 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw)
This commit adds a new counter to record the number of XIDs generated per
backend. It will help to detect if a backend is consuming XIDs at a high rate.
Virtual transactions are not taken into account on purpose, we do want to track
only the XID where there is a risk of wraparound.
The counter is not part of PgStat_BackendPending, because we want to avoid
an extra function call in this code path to increment the counter in
PendingBackendStats. The counter increment here behaves more or less the same as
we do for WAL statistics.
---
src/backend/access/transam/varsup.c | 2 ++
src/backend/utils/activity/pgstat_backend.c | 6 +++++-
src/include/pgstat.h | 3 +++
3 files changed, 10 insertions(+), 1 deletion(-)
10.1% src/backend/access/transam/
69.3% src/backend/utils/activity/
20.5% src/include/
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index fe895787cb7..26c72cbe091 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -21,6 +21,7 @@
#include "access/xlogutils.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
+#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
@@ -257,6 +258,7 @@ GetNewTransactionId(bool isSubXact)
/* LWLockRelease acts as barrier */
MyProc->xid = xid;
ProcGlobal->xids[MyProc->pgxactoff] = xid;
+ XidGenCount++;
}
else
{
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index bf164854c4b..8b530c510b9 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -52,6 +52,8 @@ static WalUsage prevBackendWalUsage;
*/
static bool backend_has_xactstats = false;
+PgStat_Counter XidGenCount = 0;
+
/*
* Utility routines to report I/O stats for backends, kept here to avoid
* exposing PendingBackendStats to the outside world.
@@ -285,9 +287,11 @@ pgstat_flush_backend_entry_xact(PgStat_EntryRef *entry_ref)
shbackendent->stats.xact_commit += PendingBackendStats.pending_xact_commit;
shbackendent->stats.xact_rollback += PendingBackendStats.pending_xact_rollback;
+ shbackendent->stats.xid_count += XidGenCount;
PendingBackendStats.pending_xact_commit = 0;
PendingBackendStats.pending_xact_rollback = 0;
+ XidGenCount = 0;
backend_has_xactstats = false;
}
@@ -317,7 +321,7 @@ pgstat_flush_backend(bool nowait, bits32 flags)
has_pending_data = true;
/* Some transaction data pending? */
- if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && backend_has_xactstats)
+ if ((flags & PGSTAT_BACKEND_FLUSH_XACT) && (backend_has_xactstats || XidGenCount > 0))
has_pending_data = true;
if (!has_pending_data)
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9efc0e10ebf..94dd24b3eac 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -492,6 +492,7 @@ typedef struct PgStat_Backend
PgStat_WalCounters wal_counters;
PgStat_Counter xact_commit;
PgStat_Counter xact_rollback;
+ PgStat_Counter xid_count;
} PgStat_Backend;
/* ---------
@@ -571,6 +572,8 @@ extern PgStat_Backend *pgstat_fetch_stat_backend_by_pid(int pid,
extern bool pgstat_tracks_backend_bktype(BackendType bktype);
extern void pgstat_create_backend(ProcNumber procnum);
+extern PGDLLIMPORT PgStat_Counter XidGenCount;
+
/*
* Functions in pgstat_bgwriter.c
*/
--
2.34.1
--u6+Li7FU79Mt/lVd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0003-Adding-the-pg_stat_backend-view.patch"
^ permalink raw reply [nested|flat] 529+ messages in thread
* [PATCH v10 1/2] Key PGSTAT_KIND_RELATION by relfile locator
@ 2025-10-01 09:45 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 529+ messages in thread
From: Bertrand Drouvot @ 2025-10-01 09:45 UTC (permalink / raw)
This patch changes the key used for the PGSTAT_KIND_RELATION statistic kind.
Instead of the relation oid, it now relies on:
- dboid (linked to RelFileLocator's dbOid)
- objoid which is the result of a new macro (namely RelFileLocatorToPgStatObjid())
that computes an objoid based on the RelFileLocator's spcOid and the
RelFileLocator's relNumber.
This is possible as, since b14e9ce7d55c, the objoid is now uint64 and spcOid
and relNumber are 32 bits.
That will allow us to add new stats (add writes counters) and ensure that some
counters (n_dead_tup and friends) are replicated.
The patch introduces pgstat_reloid_to_relfilelocator() to 1) avoid calling
RelationIdGetRelation() to get the relfilelocator based on the relation oid
and 2) handle the partitioned table case.
Please note that:
- when running pg_stat_have_stats('relation',...) we now need to be connected
to the database that hosts the relation. As pg_stat_have_stats() is not
documented publicly, then the changes done in 029_stats_restart.pl look
enough.
- this patch does not handle rewrites so some tests are failing. It's only
intent is to ease the review and should not be pushed without being
merged with the following patch that handles the rewrites.
- it can be used to test that stats are incremented correctly and that we're
able to retrieve them as long as rewrites are not involved.
---
src/backend/postmaster/autovacuum.c | 17 +-
src/backend/utils/activity/pgstat_relation.c | 236 ++++++++++++++++---
src/backend/utils/adt/pgstatfuncs.c | 22 +-
src/include/catalog/pg_tablespace.dat | 4 +
src/include/catalog/pg_tablespace.h | 8 +
src/include/pgstat.h | 15 +-
src/include/utils/pgstat_internal.h | 1 +
src/test/recovery/t/029_stats_restart.pl | 40 ++--
8 files changed, 271 insertions(+), 72 deletions(-)
6.1% src/backend/postmaster/
61.6% src/backend/utils/activity/
5.1% src/backend/utils/adt/
3.2% src/include/catalog/
5.6% src/include/
18.1% src/test/recovery/t/
diff --git a/src/backend/postmaster/autovacuum.c b/src/backend/postmaster/autovacuum.c
index 1bd3924e35e..a11174b25ad 100644
--- a/src/backend/postmaster/autovacuum.c
+++ b/src/backend/postmaster/autovacuum.c
@@ -2014,12 +2014,16 @@ do_autovacuum(void)
bool dovacuum;
bool doanalyze;
bool wraparound;
+ RelFileLocator locator;
if (classForm->relkind != RELKIND_RELATION &&
classForm->relkind != RELKIND_MATVIEW)
continue;
relid = classForm->oid;
+ locator.dbOid = classForm->relisshared ? InvalidOid : MyDatabaseId;
+ locator.spcOid = classForm->reltablespace;
+ locator.relNumber = classForm->relfilenode;
/*
* Check if it is a temp table (presumably, of some other backend's).
@@ -2048,8 +2052,7 @@ do_autovacuum(void)
/* Fetch reloptions and the pgstat entry for this table */
relopts = extract_autovac_opts(tuple, pg_class_desc);
- tabentry = pgstat_fetch_stat_tabentry_ext(classForm->relisshared,
- relid);
+ tabentry = pgstat_fetch_stat_tabentry_by_locator(locator);
/* Check if it needs vacuum or analyze */
relation_needs_vacanalyze(relid, relopts, classForm, tabentry,
@@ -2114,6 +2117,7 @@ do_autovacuum(void)
bool dovacuum;
bool doanalyze;
bool wraparound;
+ RelFileLocator locator;
/*
* We cannot safely process other backends' temp tables, so skip 'em.
@@ -2122,6 +2126,9 @@ do_autovacuum(void)
continue;
relid = classForm->oid;
+ locator.dbOid = classForm->relisshared ? InvalidOid : MyDatabaseId;
+ locator.spcOid = classForm->reltablespace;
+ locator.relNumber = classForm->relfilenode;
/*
* fetch reloptions -- if this toast table does not have them, try the
@@ -2141,8 +2148,7 @@ do_autovacuum(void)
}
/* Fetch the pgstat entry for this table */
- tabentry = pgstat_fetch_stat_tabentry_ext(classForm->relisshared,
- relid);
+ tabentry = pgstat_fetch_stat_tabentry_by_locator(locator);
relation_needs_vacanalyze(relid, relopts, classForm, tabentry,
effective_multixact_freeze_max_age,
@@ -2939,8 +2945,7 @@ recheck_relation_needs_vacanalyze(Oid relid,
PgStat_StatTabEntry *tabentry;
/* fetch the pgstat table entry */
- tabentry = pgstat_fetch_stat_tabentry_ext(classForm->relisshared,
- relid);
+ tabentry = pgstat_fetch_stat_tabentry_ext(relid);
relation_needs_vacanalyze(relid, avopts, classForm, tabentry,
effective_multixact_freeze_max_age,
diff --git a/src/backend/utils/activity/pgstat_relation.c b/src/backend/utils/activity/pgstat_relation.c
index 55a10c299db..a267e93f8be 100644
--- a/src/backend/utils/activity/pgstat_relation.c
+++ b/src/backend/utils/activity/pgstat_relation.c
@@ -17,12 +17,17 @@
#include "postgres.h"
+#include "access/htup_details.h"
#include "access/twophase_rmgr.h"
#include "access/xact.h"
#include "catalog/catalog.h"
+#include "catalog/pg_tablespace.h"
+#include "storage/lmgr.h"
#include "utils/memutils.h"
#include "utils/pgstat_internal.h"
#include "utils/rel.h"
+#include "utils/relmapper.h"
+#include "utils/syscache.h"
#include "utils/timestamp.h"
@@ -36,13 +41,12 @@ typedef struct TwoPhasePgStatRecord
PgStat_Counter inserted_pre_truncdrop;
PgStat_Counter updated_pre_truncdrop;
PgStat_Counter deleted_pre_truncdrop;
- Oid id; /* table's OID */
- bool shared; /* is it a shared catalog? */
+ RelFileLocator locator; /* table's rd_locator */
bool truncdropped; /* was the relation truncated/dropped? */
} TwoPhasePgStatRecord;
-static PgStat_TableStatus *pgstat_prep_relation_pending(Oid rel_id, bool isshared);
+static PgStat_TableStatus *pgstat_prep_relation_pending(RelFileLocator locator);
static void add_tabstat_xact_level(PgStat_TableStatus *pgstat_info, int nest_level);
static void ensure_tabstat_xact_level(PgStat_TableStatus *pgstat_info);
static void save_truncdrop_counters(PgStat_TableXactStatus *trans, bool is_drop);
@@ -60,8 +64,7 @@ pgstat_copy_relation_stats(Relation dst, Relation src)
PgStatShared_Relation *dstshstats;
PgStat_EntryRef *dst_ref;
- srcstats = pgstat_fetch_stat_tabentry_ext(src->rd_rel->relisshared,
- RelationGetRelid(src));
+ srcstats = pgstat_fetch_stat_tabentry_ext(RelationGetRelid(src));
if (!srcstats)
return;
@@ -94,8 +97,10 @@ pgstat_init_relation(Relation rel)
/*
* We only count stats for relations with storage and partitioned tables
+ * and we don't count stats generated during a rewrite.
*/
- if (!RELKIND_HAS_STORAGE(relkind) && relkind != RELKIND_PARTITIONED_TABLE)
+ if ((!RELKIND_HAS_STORAGE(relkind) && relkind != RELKIND_PARTITIONED_TABLE) ||
+ OidIsValid(rel->rd_rel->relrewrite))
{
rel->pgstat_enabled = false;
rel->pgstat_info = NULL;
@@ -130,12 +135,37 @@ pgstat_init_relation(Relation rel)
void
pgstat_assoc_relation(Relation rel)
{
+ RelFileLocator locator;
+
Assert(rel->pgstat_enabled);
Assert(rel->pgstat_info == NULL);
+ /*
+ * Don't associate stats for relations without storage and non partitioned
+ * tables.
+ */
+ if (!RELKIND_HAS_STORAGE(rel->rd_rel->relkind) &&
+ rel->rd_rel->relkind != RELKIND_PARTITIONED_TABLE)
+ return;
+
+ if (rel->rd_rel->relkind != RELKIND_PARTITIONED_TABLE)
+ locator = rel->rd_locator;
+ else
+ {
+ /*
+ * Partitioned tables don't have storage, so construct a synthetic
+ * locator for statistics tracking. Use a reserved pseudo tablespace
+ * OID that cannot conflict with real tablespaces, and the relation
+ * OID as relNumber. This ensures no collision with regular relations
+ * even after OID wraparound.
+ */
+ locator.dbOid = (rel->rd_rel->relisshared ? InvalidOid : MyDatabaseId);
+ locator.spcOid = PSEUDO_PARTITION_TABLE_SPCOID;
+ locator.relNumber = rel->rd_id;
+ }
+
/* Else find or make the PgStat_TableStatus entry, and update link */
- rel->pgstat_info = pgstat_prep_relation_pending(RelationGetRelid(rel),
- rel->rd_rel->relisshared);
+ rel->pgstat_info = pgstat_prep_relation_pending(locator);
/* don't allow link a stats to multiple relcache entries */
Assert(rel->pgstat_info->relation == NULL);
@@ -167,9 +197,13 @@ pgstat_unlink_relation(Relation rel)
void
pgstat_create_relation(Relation rel)
{
+ /* don't track stats for relations without storage */
+ if (!RELKIND_HAS_STORAGE(rel->rd_rel->relkind))
+ return;
+
pgstat_create_transactional(PGSTAT_KIND_RELATION,
- rel->rd_rel->relisshared ? InvalidOid : MyDatabaseId,
- RelationGetRelid(rel));
+ rel->rd_locator.dbOid,
+ RelFileLocatorToPgStatObjid(rel->rd_locator));
}
/*
@@ -181,9 +215,13 @@ pgstat_drop_relation(Relation rel)
int nest_level = GetCurrentTransactionNestLevel();
PgStat_TableStatus *pgstat_info;
+ /* don't track stats for relations without storage */
+ if (!RELKIND_HAS_STORAGE(rel->rd_rel->relkind))
+ return;
+
pgstat_drop_transactional(PGSTAT_KIND_RELATION,
- rel->rd_rel->relisshared ? InvalidOid : MyDatabaseId,
- RelationGetRelid(rel));
+ rel->rd_locator.dbOid,
+ RelFileLocatorToPgStatObjid(rel->rd_locator));
if (!pgstat_should_count_relation(rel))
return;
@@ -213,20 +251,23 @@ pgstat_report_vacuum(Relation rel, PgStat_Counter livetuples,
PgStat_EntryRef *entry_ref;
PgStatShared_Relation *shtabentry;
PgStat_StatTabEntry *tabentry;
- Oid dboid = (rel->rd_rel->relisshared ? InvalidOid : MyDatabaseId);
TimestampTz ts;
PgStat_Counter elapsedtime;
+ RelFileLocator locator;
if (!pgstat_track_counts)
return;
+ locator = rel->rd_locator;
+
/* Store the data in the table's hash table entry. */
ts = GetCurrentTimestamp();
elapsedtime = TimestampDifferenceMilliseconds(starttime, ts);
/* block acquiring lock for the same reason as pgstat_report_autovac() */
- entry_ref = pgstat_get_entry_ref_locked(PGSTAT_KIND_RELATION, dboid,
- RelationGetRelid(rel), false);
+ entry_ref = pgstat_get_entry_ref_locked(PGSTAT_KIND_RELATION, locator.dbOid,
+ RelFileLocatorToPgStatObjid(locator),
+ false);
shtabentry = (PgStatShared_Relation *) entry_ref->shared_stats;
tabentry = &shtabentry->stats;
@@ -285,9 +326,9 @@ pgstat_report_analyze(Relation rel,
PgStat_EntryRef *entry_ref;
PgStatShared_Relation *shtabentry;
PgStat_StatTabEntry *tabentry;
- Oid dboid = (rel->rd_rel->relisshared ? InvalidOid : MyDatabaseId);
TimestampTz ts;
PgStat_Counter elapsedtime;
+ RelFileLocator locator;
if (!pgstat_track_counts)
return;
@@ -325,9 +366,25 @@ pgstat_report_analyze(Relation rel,
ts = GetCurrentTimestamp();
elapsedtime = TimestampDifferenceMilliseconds(starttime, ts);
+ if (rel->rd_rel->relkind != RELKIND_PARTITIONED_TABLE)
+ locator = rel->rd_locator;
+ else
+ {
+ /*
+ * Partitioned tables don't have storage, so construct a synthetic
+ * locator for statistics tracking. Use a reserved pseudo tablespace
+ * OID that cannot conflict with real tablespaces, and the relation
+ * OID as relNumber. This ensures no collision with regular relations
+ * even after OID wraparound.
+ */
+ locator.dbOid = (rel->rd_rel->relisshared ? InvalidOid : MyDatabaseId);
+ locator.spcOid = PSEUDO_PARTITION_TABLE_SPCOID;
+ locator.relNumber = rel->rd_id;
+ }
/* block acquiring lock for the same reason as pgstat_report_autovac() */
- entry_ref = pgstat_get_entry_ref_locked(PGSTAT_KIND_RELATION, dboid,
- RelationGetRelid(rel),
+ entry_ref = pgstat_get_entry_ref_locked(PGSTAT_KIND_RELATION,
+ locator.dbOid,
+ RelFileLocatorToPgStatObjid(locator),
false);
/* can't get dropped while accessed */
Assert(entry_ref != NULL && entry_ref->shared_stats != NULL);
@@ -468,7 +525,16 @@ pgstat_update_heap_dead_tuples(Relation rel, int delta)
PgStat_StatTabEntry *
pgstat_fetch_stat_tabentry(Oid relid)
{
- return pgstat_fetch_stat_tabentry_ext(IsSharedRelation(relid), relid);
+ return pgstat_fetch_stat_tabentry_ext(relid);
+}
+
+PgStat_StatTabEntry *
+pgstat_fetch_stat_tabentry_by_locator(RelFileLocator locator)
+{
+ return (PgStat_StatTabEntry *) pgstat_fetch_entry(
+ PGSTAT_KIND_RELATION,
+ locator.dbOid,
+ RelFileLocatorToPgStatObjid(locator));
}
/*
@@ -476,12 +542,14 @@ pgstat_fetch_stat_tabentry(Oid relid)
* whether the to-be-accessed table is a shared relation or not.
*/
PgStat_StatTabEntry *
-pgstat_fetch_stat_tabentry_ext(bool shared, Oid reloid)
+pgstat_fetch_stat_tabentry_ext(Oid reloid)
{
- Oid dboid = (shared ? InvalidOid : MyDatabaseId);
+ RelFileLocator locator;
- return (PgStat_StatTabEntry *)
- pgstat_fetch_entry(PGSTAT_KIND_RELATION, dboid, reloid);
+ if (!pgstat_reloid_to_relfilelocator(reloid, &locator))
+ return NULL;
+
+ return pgstat_fetch_stat_tabentry_by_locator(locator);
}
/*
@@ -503,14 +571,17 @@ find_tabstat_entry(Oid rel_id)
PgStat_TableXactStatus *trans;
PgStat_TableStatus *tabentry = NULL;
PgStat_TableStatus *tablestatus = NULL;
+ RelFileLocator locator;
+
+ if (!pgstat_reloid_to_relfilelocator(rel_id, &locator))
+ return NULL;
+
+ entry_ref = pgstat_fetch_pending_entry(PGSTAT_KIND_RELATION,
+ locator.dbOid,
+ RelFileLocatorToPgStatObjid(locator));
- entry_ref = pgstat_fetch_pending_entry(PGSTAT_KIND_RELATION, MyDatabaseId, rel_id);
if (!entry_ref)
- {
- entry_ref = pgstat_fetch_pending_entry(PGSTAT_KIND_RELATION, InvalidOid, rel_id);
- if (!entry_ref)
- return tablestatus;
- }
+ return tablestatus;
tabentry = (PgStat_TableStatus *) entry_ref->pending;
tablestatus = palloc_object(PgStat_TableStatus);
@@ -706,8 +777,12 @@ AtPrepare_PgStat_Relations(PgStat_SubXactStatus *xact_state)
record.inserted_pre_truncdrop = trans->inserted_pre_truncdrop;
record.updated_pre_truncdrop = trans->updated_pre_truncdrop;
record.deleted_pre_truncdrop = trans->deleted_pre_truncdrop;
- record.id = tabstat->id;
- record.shared = tabstat->shared;
+
+ if (tabstat->relation != NULL)
+ record.locator = tabstat->relation->rd_locator;
+ else
+ record.locator = tabstat->locator;
+
record.truncdropped = trans->truncdropped;
RegisterTwoPhaseRecord(TWOPHASE_RM_PGSTAT_ID, 0,
@@ -750,7 +825,7 @@ pgstat_twophase_postcommit(FullTransactionId fxid, uint16 info,
PgStat_TableStatus *pgstat_info;
/* Find or create a tabstat entry for the rel */
- pgstat_info = pgstat_prep_relation_pending(rec->id, rec->shared);
+ pgstat_info = pgstat_prep_relation_pending(rec->locator);
/* Same math as in AtEOXact_PgStat, commit case */
pgstat_info->counts.tuples_inserted += rec->tuples_inserted;
@@ -785,8 +860,8 @@ pgstat_twophase_postabort(FullTransactionId fxid, uint16 info,
TwoPhasePgStatRecord *rec = (TwoPhasePgStatRecord *) recdata;
PgStat_TableStatus *pgstat_info;
- /* Find or create a tabstat entry for the rel */
- pgstat_info = pgstat_prep_relation_pending(rec->id, rec->shared);
+ /* Find or create a tabstat entry for the target locator */
+ pgstat_info = pgstat_prep_relation_pending(rec->locator);
/* Same math as in AtEOXact_PgStat, abort case */
if (rec->truncdropped)
@@ -920,17 +995,21 @@ pgstat_relation_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts)
* initialized if not exists.
*/
static PgStat_TableStatus *
-pgstat_prep_relation_pending(Oid rel_id, bool isshared)
+pgstat_prep_relation_pending(RelFileLocator locator)
{
PgStat_EntryRef *entry_ref;
PgStat_TableStatus *pending;
+ uint64 objid;
+
+ objid = RelFileLocatorToPgStatObjid(locator);
entry_ref = pgstat_prep_pending_entry(PGSTAT_KIND_RELATION,
- isshared ? InvalidOid : MyDatabaseId,
- rel_id, NULL);
+ locator.dbOid,
+ objid, NULL);
+
pending = entry_ref->pending;
- pending->id = rel_id;
- pending->shared = isshared;
+ pending->id = objid;
+ pending->locator = locator;
return pending;
}
@@ -1009,3 +1088,82 @@ restore_truncdrop_counters(PgStat_TableXactStatus *trans)
trans->tuples_deleted = trans->deleted_pre_truncdrop;
}
}
+
+/*
+ * Convert a relation OID to its corresponding RelFileLocator for statistics
+ * tracking purposes.
+ *
+ * Returns true on success, false if the relation doesn't need statistics
+ * tracking.
+ *
+ * For partitioned tables, constructs a synthetic locator using the relation
+ * OID as relNumber, since they don't have storage.
+ */
+bool
+pgstat_reloid_to_relfilelocator(Oid reloid, RelFileLocator *locator)
+{
+ HeapTuple tuple;
+ Form_pg_class relform;
+ bool result = true;
+
+ /* get the relation's tuple from pg_class */
+ tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(reloid));
+
+ if (!HeapTupleIsValid(tuple))
+ return false;
+
+ relform = (Form_pg_class) GETSTRUCT(tuple);
+
+ /* skip relations without storage and non partitioned tables */
+ if (!RELKIND_HAS_STORAGE(relform->relkind) &&
+ relform->relkind != RELKIND_PARTITIONED_TABLE)
+ {
+ ReleaseSysCache(tuple);
+ return false;
+ }
+
+ if (relform->relkind != RELKIND_PARTITIONED_TABLE)
+ {
+ /* build the RelFileLocator */
+ locator->relNumber = relform->relfilenode;
+ locator->spcOid = relform->reltablespace;
+
+ /* handle default tablespace */
+ if (!OidIsValid(locator->spcOid))
+ locator->spcOid = MyDatabaseTableSpace;
+
+ /* handle dbOid for global vs local relations */
+ if (locator->spcOid == GLOBALTABLESPACE_OID)
+ locator->dbOid = InvalidOid;
+ else
+ locator->dbOid = MyDatabaseId;
+
+ /* handle mapped relations */
+ if (!RelFileNumberIsValid(locator->relNumber))
+ {
+ locator->relNumber = RelationMapOidToFilenumber(reloid,
+ relform->relisshared);
+ if (!RelFileNumberIsValid(locator->relNumber))
+ {
+ ReleaseSysCache(tuple);
+ return false;
+ }
+ }
+ }
+ else
+ {
+ /*
+ * Partitioned tables don't have storage, so construct a synthetic
+ * locator for statistics tracking. Use a reserved pseudo tablespace
+ * OID that cannot conflict with real tablespaces, and the relation
+ * OID as relNumber. This ensures no collision with regular relations
+ * even after OID wraparound.
+ */
+ locator->dbOid = (relform->relisshared ? InvalidOid : MyDatabaseId);
+ locator->spcOid = PSEUDO_PARTITION_TABLE_SPCOID;
+ locator->relNumber = relform->oid;
+ }
+
+ ReleaseSysCache(tuple);
+ return result;
+}
diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
index ef6fffe60b9..60ffb1679ec 100644
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -23,13 +23,13 @@
#include "common/ip.h"
#include "funcapi.h"
#include "miscadmin.h"
-#include "pgstat.h"
#include "postmaster/bgworker.h"
#include "replication/logicallauncher.h"
#include "storage/proc.h"
#include "storage/procarray.h"
#include "utils/acl.h"
#include "utils/builtins.h"
+#include "utils/pgstat_internal.h"
#include "utils/timestamp.h"
#define UINT32_ACCESS_ONCE(var) ((uint32)(*((volatile uint32 *)&(var))))
@@ -1949,9 +1949,14 @@ Datum
pg_stat_reset_single_table_counters(PG_FUNCTION_ARGS)
{
Oid taboid = PG_GETARG_OID(0);
- Oid dboid = (IsSharedRelation(taboid) ? InvalidOid : MyDatabaseId);
+ RelFileLocator locator;
- pgstat_reset(PGSTAT_KIND_RELATION, dboid, taboid);
+ /* Get the stats locator from the relation OID */
+ if (!pgstat_reloid_to_relfilelocator(taboid, &locator))
+ PG_RETURN_VOID();
+
+ pgstat_reset(PGSTAT_KIND_RELATION, locator.dbOid,
+ RelFileLocatorToPgStatObjid(locator));
PG_RETURN_VOID();
}
@@ -2305,5 +2310,16 @@ pg_stat_have_stats(PG_FUNCTION_ARGS)
uint64 objid = PG_GETARG_INT64(2);
PgStat_Kind kind = pgstat_get_kind_from_str(stats_type);
+ /* Convert relation OID to relfilenode objid */
+ if (kind == PGSTAT_KIND_RELATION)
+ {
+ RelFileLocator locator;
+
+ if (!pgstat_reloid_to_relfilelocator(objid, &locator))
+ PG_RETURN_BOOL(false);
+
+ objid = RelFileLocatorToPgStatObjid(locator);
+ }
+
PG_RETURN_BOOL(pgstat_have_entry(kind, dboid, objid));
}
diff --git a/src/include/catalog/pg_tablespace.dat b/src/include/catalog/pg_tablespace.dat
index 1302a3d75cd..9430970fffd 100644
--- a/src/include/catalog/pg_tablespace.dat
+++ b/src/include/catalog/pg_tablespace.dat
@@ -10,6 +10,10 @@
#
#----------------------------------------------------------------------
+/*
+ * When adding a new one, ensure it does not conflict with
+ * PSEUDO_PARTITION_TABLE_SPCOID.
+ */
[
{ oid => '1663', oid_symbol => 'DEFAULTTABLESPACE_OID',
diff --git a/src/include/catalog/pg_tablespace.h b/src/include/catalog/pg_tablespace.h
index 7816d779d8c..0e2d8051d69 100644
--- a/src/include/catalog/pg_tablespace.h
+++ b/src/include/catalog/pg_tablespace.h
@@ -21,6 +21,14 @@
#include "catalog/genbki.h"
#include "catalog/pg_tablespace_d.h" /* IWYU pragma: export */
+/*
+ * Reserved tablespace OID for partitioned table pseudo locators.
+ * This is not an actual tablespace, just a reserved value to distinguish
+ * partitioned table statistics from regular table statistics. Ensures it does
+ * not conflict with the ones in pg_tablespace.dat.
+ */
+#define PSEUDO_PARTITION_TABLE_SPCOID 1665
+
/* ----------------
* pg_tablespace definition. cpp turns this into
* typedef struct FormData_pg_tablespace
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 6714363144a..3102f86aa24 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -17,6 +17,7 @@
#include "postmaster/pgarch.h" /* for MAX_XFN_CHARS */
#include "replication/conflict.h"
#include "replication/worker_internal.h"
+#include "storage/relfilelocator.h"
#include "utils/backend_progress.h" /* for backward compatibility */ /* IWYU pragma: export */
#include "utils/backend_status.h" /* for backward compatibility */ /* IWYU pragma: export */
#include "utils/pgstat_kind.h"
@@ -35,6 +36,12 @@
/* Default directory to store temporary statistics data in */
#define PG_STAT_TMP_DIR "pg_stat_tmp"
+/*
+ * Build a pgstat key Objid based on a RelFileLocator.
+ */
+#define RelFileLocatorToPgStatObjid(locator) \
+ (((uint64) (locator).spcOid << 32) | (locator).relNumber)
+
/* Values for track_functions GUC variable --- order is significant! */
typedef enum TrackFunctionsLevel
{
@@ -175,11 +182,11 @@ typedef struct PgStat_TableCounts
*/
typedef struct PgStat_TableStatus
{
- Oid id; /* table's OID */
- bool shared; /* is it a shared catalog? */
+ uint64 id; /* hash of relfilelocator for stats key */
struct PgStat_TableXactStatus *trans; /* lowest subxact's counts */
PgStat_TableCounts counts; /* event counts to be sent */
Relation relation; /* rel that is using this entry */
+ RelFileLocator locator; /* table's relfilelocator */
} PgStat_TableStatus;
/* ----------
@@ -735,8 +742,8 @@ extern void pgstat_twophase_postabort(FullTransactionId fxid, uint16 info,
void *recdata, uint32 len);
extern PgStat_StatTabEntry *pgstat_fetch_stat_tabentry(Oid relid);
-extern PgStat_StatTabEntry *pgstat_fetch_stat_tabentry_ext(bool shared,
- Oid reloid);
+extern PgStat_StatTabEntry *pgstat_fetch_stat_tabentry_by_locator(RelFileLocator locator);
+extern PgStat_StatTabEntry *pgstat_fetch_stat_tabentry_ext(Oid reloid);
extern PgStat_TableStatus *find_tabstat_entry(Oid rel_id);
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 5c1ce4d3d6a..7b24928b00d 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -764,6 +764,7 @@ extern void PostPrepare_PgStat_Relations(PgStat_SubXactStatus *xact_state);
extern bool pgstat_relation_flush_cb(PgStat_EntryRef *entry_ref, bool nowait);
extern void pgstat_relation_delete_pending_cb(PgStat_EntryRef *entry_ref);
extern void pgstat_relation_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts);
+extern bool pgstat_reloid_to_relfilelocator(Oid reloid, RelFileLocator *locator);
/*
diff --git a/src/test/recovery/t/029_stats_restart.pl b/src/test/recovery/t/029_stats_restart.pl
index 021e2bf361f..3a9c05eaf10 100644
--- a/src/test/recovery/t/029_stats_restart.pl
+++ b/src/test/recovery/t/029_stats_restart.pl
@@ -55,10 +55,10 @@ trigger_funcrel_stat();
# verify stats objects exist
$sect = "initial";
-is(have_stats('database', $dboid, 0), 't', "$sect: db stats do exist");
-is(have_stats('function', $dboid, $funcoid),
+is(have_stats($connect_db, 'database', $dboid, 0), 't', "$sect: db stats do exist");
+is(have_stats($db_under_test, 'function', $dboid, $funcoid),
't', "$sect: function stats do exist");
-is(have_stats('relation', $dboid, $tableoid),
+is(have_stats($db_under_test, 'relation', $dboid, $tableoid),
't', "$sect: relation stats do exist");
# regular shutdown
@@ -79,10 +79,10 @@ copy($og_stats, $statsfile) or die "Copy failed: $!";
$node->start;
$sect = "copy";
-is(have_stats('database', $dboid, 0), 't', "$sect: db stats do exist");
-is(have_stats('function', $dboid, $funcoid),
+is(have_stats($connect_db, 'database', $dboid, 0), 't', "$sect: db stats do exist");
+is(have_stats($db_under_test, 'function', $dboid, $funcoid),
't', "$sect: function stats do exist");
-is(have_stats('relation', $dboid, $tableoid),
+is(have_stats($db_under_test, 'relation', $dboid, $tableoid),
't', "$sect: relation stats do exist");
$node->stop('immediate');
@@ -96,10 +96,10 @@ $node->start;
# stats should have been discarded
$sect = "post immediate";
-is(have_stats('database', $dboid, 0), 'f', "$sect: db stats do not exist");
-is(have_stats('function', $dboid, $funcoid),
+is(have_stats($connect_db, 'database', $dboid, 0), 'f', "$sect: db stats do not exist");
+is(have_stats($db_under_test, 'function', $dboid, $funcoid),
'f', "$sect: function stats do exist");
-is(have_stats('relation', $dboid, $tableoid),
+is(have_stats($db_under_test, 'relation', $dboid, $tableoid),
'f', "$sect: relation stats do not exist");
# get rid of backup statsfile
@@ -110,10 +110,10 @@ unlink $statsfile or die "cannot unlink $statsfile $!";
trigger_funcrel_stat();
$sect = "post immediate, new";
-is(have_stats('database', $dboid, 0), 't', "$sect: db stats do exist");
-is(have_stats('function', $dboid, $funcoid),
+is(have_stats($connect_db, 'database', $dboid, 0), 't', "$sect: db stats do exist");
+is(have_stats($db_under_test, 'function', $dboid, $funcoid),
't', "$sect: function stats do exist");
-is(have_stats('relation', $dboid, $tableoid),
+is(have_stats($db_under_test, 'relation', $dboid, $tableoid),
't', "$sect: relation stats do exist");
# regular shutdown
@@ -129,10 +129,10 @@ $node->start;
# no stats present due to invalid stats file
$sect = "invalid_overwrite";
-is(have_stats('database', $dboid, 0), 'f', "$sect: db stats do not exist");
-is(have_stats('function', $dboid, $funcoid),
+is(have_stats($connect_db, 'database', $dboid, 0), 'f', "$sect: db stats do not exist");
+is(have_stats($db_under_test, 'function', $dboid, $funcoid),
'f', "$sect: function stats do not exist");
-is(have_stats('relation', $dboid, $tableoid),
+is(have_stats($db_under_test, 'relation', $dboid, $tableoid),
'f', "$sect: relation stats do not exist");
@@ -145,10 +145,10 @@ append_file($og_stats, "XYZ");
$node->start;
$sect = "invalid_append";
-is(have_stats('database', $dboid, 0), 'f', "$sect: db stats do not exist");
-is(have_stats('function', $dboid, $funcoid),
+is(have_stats($connect_db, 'database', $dboid, 0), 'f', "$sect: db stats do not exist");
+is(have_stats($db_under_test, 'function', $dboid, $funcoid),
'f', "$sect: function stats do not exist");
-is(have_stats('relation', $dboid, $tableoid),
+is(have_stats($db_under_test, 'relation', $dboid, $tableoid),
'f', "$sect: relation stats do not exist");
@@ -307,9 +307,9 @@ sub trigger_funcrel_stat
sub have_stats
{
- my ($kind, $dboid, $objid) = @_;
+ my ($db, $kind, $dboid, $objid) = @_;
- return $node->safe_psql($connect_db,
+ return $node->safe_psql($db,
"SELECT pg_stat_have_stats('$kind', $dboid, $objid)");
}
--
2.34.1
--xJsrX25x3tm7Tn81
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v10-0002-handle-relation-statistics-correctly-during-rewr.patch"
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2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v3 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v4 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-08-08 15:58 [PATCH v5 2/3] Adding XID generation count per backend Bertrand Drouvot <[email protected]>
2025-10-01 09:45 [PATCH v10 1/2] Key PGSTAT_KIND_RELATION by relfile locator Bertrand Drouvot <[email protected]>
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