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[PATCH v24 4/8] Row pattern recognition patch (planner). 238+ messages / 2 participants [nested] [flat]
* [PATCH v24 4/8] Row pattern recognition patch (planner). @ 2024-12-19 06:06 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 238+ messages in thread From: Tatsuo Ishii @ 2024-12-19 06:06 UTC (permalink / raw) --- src/backend/optimizer/plan/createplan.c | 24 +++++++++++++++----- src/backend/optimizer/plan/planner.c | 3 +++ src/backend/optimizer/plan/setrefs.c | 27 ++++++++++++++++++++++- src/backend/optimizer/prep/prepjointree.c | 9 ++++++++ src/include/nodes/plannodes.h | 19 ++++++++++++++++ 5 files changed, 76 insertions(+), 6 deletions(-) diff --git a/src/backend/optimizer/plan/createplan.c b/src/backend/optimizer/plan/createplan.c index 178c572b02..2aedb43791 100644 --- a/src/backend/optimizer/plan/createplan.c +++ b/src/backend/optimizer/plan/createplan.c @@ -290,9 +290,11 @@ static WindowAgg *make_windowagg(List *tlist, Index winref, int ordNumCols, AttrNumber *ordColIdx, Oid *ordOperators, Oid *ordCollations, int frameOptions, Node *startOffset, Node *endOffset, Oid startInRangeFunc, Oid endInRangeFunc, - Oid inRangeColl, bool inRangeAsc, bool inRangeNullsFirst, - List *runCondition, List *qual, bool topWindow, - Plan *lefttree); + Oid inRangeColl, bool inRangeAsc, bool inRangeNullsFirst, List *runCondition, + RPSkipTo rpSkipTo, List *patternVariable, List *patternRegexp, + List *defineClause, + List *defineInitial, + List *qual, bool topWindow, Plan *lefttree); static Group *make_group(List *tlist, List *qual, int numGroupCols, AttrNumber *grpColIdx, Oid *grpOperators, Oid *grpCollations, Plan *lefttree); @@ -2700,6 +2702,11 @@ create_windowagg_plan(PlannerInfo *root, WindowAggPath *best_path) wc->inRangeAsc, wc->inRangeNullsFirst, best_path->runCondition, + wc->rpSkipTo, + wc->patternVariable, + wc->patternRegexp, + wc->defineClause, + wc->defineInitial, best_path->qual, best_path->topwindow, subplan); @@ -6704,8 +6711,10 @@ make_windowagg(List *tlist, Index winref, int ordNumCols, AttrNumber *ordColIdx, Oid *ordOperators, Oid *ordCollations, int frameOptions, Node *startOffset, Node *endOffset, Oid startInRangeFunc, Oid endInRangeFunc, - Oid inRangeColl, bool inRangeAsc, bool inRangeNullsFirst, - List *runCondition, List *qual, bool topWindow, Plan *lefttree) + Oid inRangeColl, bool inRangeAsc, bool inRangeNullsFirst, List *runCondition, + RPSkipTo rpSkipTo, List *patternVariable, List *patternRegexp, List *defineClause, + List *defineInitial, + List *qual, bool topWindow, Plan *lefttree) { WindowAgg *node = makeNode(WindowAgg); Plan *plan = &node->plan; @@ -6731,6 +6740,11 @@ make_windowagg(List *tlist, Index winref, node->inRangeAsc = inRangeAsc; node->inRangeNullsFirst = inRangeNullsFirst; node->topWindow = topWindow; + node->rpSkipTo = rpSkipTo, + node->patternVariable = patternVariable; + node->patternRegexp = patternRegexp; + node->defineClause = defineClause; + node->defineInitial = defineInitial; plan->targetlist = tlist; plan->lefttree = lefttree; diff --git a/src/backend/optimizer/plan/planner.c b/src/backend/optimizer/plan/planner.c index a0a2de7ee4..e11935aeb8 100644 --- a/src/backend/optimizer/plan/planner.c +++ b/src/backend/optimizer/plan/planner.c @@ -881,6 +881,9 @@ subquery_planner(PlannerGlobal *glob, Query *parse, PlannerInfo *parent_root, EXPRKIND_LIMIT); wc->endOffset = preprocess_expression(root, wc->endOffset, EXPRKIND_LIMIT); + wc->defineClause = (List *) preprocess_expression(root, + (Node *) wc->defineClause, + EXPRKIND_TARGET); } parse->limitOffset = preprocess_expression(root, parse->limitOffset, diff --git a/src/backend/optimizer/plan/setrefs.c b/src/backend/optimizer/plan/setrefs.c index 6d23df108d..70c9733e3f 100644 --- a/src/backend/optimizer/plan/setrefs.c +++ b/src/backend/optimizer/plan/setrefs.c @@ -211,7 +211,6 @@ static List *set_windowagg_runcondition_references(PlannerInfo *root, List *runcondition, Plan *plan); - /***************************************************************************** * * SUBPLAN REFERENCES @@ -2492,6 +2491,32 @@ set_upper_references(PlannerInfo *root, Plan *plan, int rtoffset) NRM_EQUAL, NUM_EXEC_QUAL(plan)); + /* + * Modifies an expression tree in each DEFINE clause so that all Var + * nodes's varno refers to OUTER_VAR. + */ + if (IsA(plan, WindowAgg)) + { + WindowAgg *wplan = (WindowAgg *) plan; + + if (wplan->defineClause != NIL) + { + foreach(l, wplan->defineClause) + { + TargetEntry *tle = (TargetEntry *) lfirst(l); + + tle->expr = (Expr *) + fix_upper_expr(root, + (Node *) tle->expr, + subplan_itlist, + OUTER_VAR, + rtoffset, + NRM_EQUAL, + NUM_EXEC_QUAL(plan)); + } + } + } + pfree(subplan_itlist); } diff --git a/src/backend/optimizer/prep/prepjointree.c b/src/backend/optimizer/prep/prepjointree.c index 3fa4d78c3e..3ef9cbff27 100644 --- a/src/backend/optimizer/prep/prepjointree.c +++ b/src/backend/optimizer/prep/prepjointree.c @@ -2298,6 +2298,15 @@ perform_pullup_replace_vars(PlannerInfo *root, parse->returningList = (List *) pullup_replace_vars((Node *) parse->returningList, rvcontext); + foreach(lc, parse->windowClause) + { + WindowClause *wc = lfirst_node(WindowClause, lc); + + if (wc->defineClause != NIL) + wc->defineClause = (List *) + pullup_replace_vars((Node *) wc->defineClause, rvcontext); + } + if (parse->onConflict) { parse->onConflict->onConflictSet = (List *) diff --git a/src/include/nodes/plannodes.h b/src/include/nodes/plannodes.h index 52f29bcdb6..294597461b 100644 --- a/src/include/nodes/plannodes.h +++ b/src/include/nodes/plannodes.h @@ -20,6 +20,7 @@ #include "lib/stringinfo.h" #include "nodes/bitmapset.h" #include "nodes/lockoptions.h" +#include "nodes/parsenodes.h" #include "nodes/primnodes.h" @@ -1099,6 +1100,24 @@ typedef struct WindowAgg /* nulls sort first for in_range tests? */ bool inRangeNullsFirst; + /* Row Pattern Recognition AFTER MACH SKIP clause */ + RPSkipTo rpSkipTo; /* Row Pattern Skip To type */ + + /* Row Pattern PATTERN variable name (list of String) */ + List *patternVariable; + + /* + * Row Pattern RPATTERN regular expression quantifier ('+' or ''. list of + * String) + */ + List *patternRegexp; + + /* Row Pattern DEFINE clause (list of TargetEntry) */ + List *defineClause; + + /* Row Pattern DEFINE variable initial names (list of String) */ + List *defineInitial; + /* * false for all apart from the WindowAgg that's closest to the root of * the plan -- 2.25.1 ----Next_Part(Thu_Dec_19_15_19_50_2024_894)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v24-0005-Row-pattern-recognition-patch-executor.patch" ^ permalink raw reply [nested|flat] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. 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] 238+ 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; 238+ messages in thread From: Bertrand Drouvot @ 2025-08-08 15:58 UTC (permalink / raw) This commit adds a new counter to record the number of XIDs generated per backend. It will help to detect if a backend is consuming XIDs at a high rate. Virtual transactions are not taken into account on purpose, we do want to track only the XID where there is a risk of wraparound. --- src/backend/access/transam/varsup.c | 4 ++++ src/backend/utils/activity/pgstat_backend.c | 2 ++ src/include/pgstat.h | 2 ++ 3 files changed, 8 insertions(+) 43.8% src/backend/access/transam/ 36.6% src/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] 238+ messages in thread
end of thread, other threads:[~2025-08-08 15:58 UTC | newest] Thread overview: 238+ messages (download: mbox mbox.gz follow: Atom feed) -- links below jump to the message on this page -- 2024-12-19 06:06 [PATCH v24 4/8] Row pattern recognition patch (planner). Tatsuo Ishii <[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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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]>
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