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* [PATCH v8 1/4] Make binaryheap available to frontend code.
@ 2023-07-22 22:04 Nathan Bossart <[email protected]>
0 siblings, 0 replies; 12+ messages in thread
From: Nathan Bossart @ 2023-07-22 22:04 UTC (permalink / raw)
There are a couple of places in frontend code that could make use
of this simple binary heap implementation. This commit makes
binaryheap usable in frontend code, much like commit 26aaf97b68 did
for StringInfo. Like StringInfo, the header file is left in lib/
to reduce the likelihood of unnecessary breakage.
The frontend version of binaryheap exposes a void *-based API since
frontend code does not have access to the Datum definitions. This
seemed like a better approach than switching all existing uses to
void * or making the Datum definitions available to frontend code.
Reviewed-by: Tom Lane, Alvaro Herrera
Discussion: https://postgr.es/m/3612876.1689443232%40sss.pgh.pa.us
---
src/backend/lib/Makefile | 1 -
src/backend/lib/meson.build | 1 -
src/common/Makefile | 1 +
src/{backend/lib => common}/binaryheap.c | 41 +++++++++++++++++-------
src/common/meson.build | 1 +
src/include/lib/binaryheap.h | 26 +++++++++++----
src/tools/pgindent/typedefs.list | 1 +
7 files changed, 52 insertions(+), 20 deletions(-)
rename src/{backend/lib => common}/binaryheap.c (90%)
diff --git a/src/backend/lib/Makefile b/src/backend/lib/Makefile
index 9dad31398a..b6cefd9cca 100644
--- a/src/backend/lib/Makefile
+++ b/src/backend/lib/Makefile
@@ -13,7 +13,6 @@ top_builddir = ../../..
include $(top_builddir)/src/Makefile.global
OBJS = \
- binaryheap.o \
bipartite_match.o \
bloomfilter.o \
dshash.o \
diff --git a/src/backend/lib/meson.build b/src/backend/lib/meson.build
index 974cab8776..b4e88f54ae 100644
--- a/src/backend/lib/meson.build
+++ b/src/backend/lib/meson.build
@@ -1,7 +1,6 @@
# Copyright (c) 2022-2023, PostgreSQL Global Development Group
backend_sources += files(
- 'binaryheap.c',
'bipartite_match.c',
'bloomfilter.c',
'dshash.c',
diff --git a/src/common/Makefile b/src/common/Makefile
index 113029bf7b..cc5c54dcee 100644
--- a/src/common/Makefile
+++ b/src/common/Makefile
@@ -48,6 +48,7 @@ LIBS += $(PTHREAD_LIBS)
OBJS_COMMON = \
archive.o \
base64.o \
+ binaryheap.o \
checksum_helper.o \
compression.o \
config_info.o \
diff --git a/src/backend/lib/binaryheap.c b/src/common/binaryheap.c
similarity index 90%
rename from src/backend/lib/binaryheap.c
rename to src/common/binaryheap.c
index 1737546757..39a8243a6d 100644
--- a/src/backend/lib/binaryheap.c
+++ b/src/common/binaryheap.c
@@ -6,15 +6,22 @@
* Portions Copyright (c) 2012-2023, PostgreSQL Global Development Group
*
* IDENTIFICATION
- * src/backend/lib/binaryheap.c
+ * src/common/binaryheap.c
*
*-------------------------------------------------------------------------
*/
+#ifdef FRONTEND
+#include "postgres_fe.h"
+#else
#include "postgres.h"
+#endif
#include <math.h>
+#ifdef FRONTEND
+#include "common/logging.h"
+#endif
#include "lib/binaryheap.h"
static void sift_down(binaryheap *heap, int node_off);
@@ -34,7 +41,7 @@ binaryheap_allocate(int capacity, binaryheap_comparator compare, void *arg)
int sz;
binaryheap *heap;
- sz = offsetof(binaryheap, bh_nodes) + sizeof(Datum) * capacity;
+ sz = offsetof(binaryheap, bh_nodes) + sizeof(bh_node_type) * capacity;
heap = (binaryheap *) palloc(sz);
heap->bh_space = capacity;
heap->bh_compare = compare;
@@ -106,10 +113,16 @@ parent_offset(int i)
* afterwards.
*/
void
-binaryheap_add_unordered(binaryheap *heap, Datum d)
+binaryheap_add_unordered(binaryheap *heap, bh_node_type d)
{
if (heap->bh_size >= heap->bh_space)
+ {
+#ifdef FRONTEND
+ pg_fatal("out of binary heap slots");
+#else
elog(ERROR, "out of binary heap slots");
+#endif
+ }
heap->bh_has_heap_property = false;
heap->bh_nodes[heap->bh_size] = d;
heap->bh_size++;
@@ -138,10 +151,16 @@ binaryheap_build(binaryheap *heap)
* the heap property.
*/
void
-binaryheap_add(binaryheap *heap, Datum d)
+binaryheap_add(binaryheap *heap, bh_node_type d)
{
if (heap->bh_size >= heap->bh_space)
+ {
+#ifdef FRONTEND
+ pg_fatal("out of binary heap slots");
+#else
elog(ERROR, "out of binary heap slots");
+#endif
+ }
heap->bh_nodes[heap->bh_size] = d;
heap->bh_size++;
sift_up(heap, heap->bh_size - 1);
@@ -154,7 +173,7 @@ binaryheap_add(binaryheap *heap, Datum d)
* without modifying the heap. The caller must ensure that this
* routine is not used on an empty heap. Always O(1).
*/
-Datum
+bh_node_type
binaryheap_first(binaryheap *heap)
{
Assert(!binaryheap_empty(heap) && heap->bh_has_heap_property);
@@ -169,10 +188,10 @@ binaryheap_first(binaryheap *heap)
* that this routine is not used on an empty heap. O(log n) worst
* case.
*/
-Datum
+bh_node_type
binaryheap_remove_first(binaryheap *heap)
{
- Datum result;
+ bh_node_type result;
Assert(!binaryheap_empty(heap) && heap->bh_has_heap_property);
@@ -204,7 +223,7 @@ binaryheap_remove_first(binaryheap *heap)
* sifting the new node down.
*/
void
-binaryheap_replace_first(binaryheap *heap, Datum d)
+binaryheap_replace_first(binaryheap *heap, bh_node_type d)
{
Assert(!binaryheap_empty(heap) && heap->bh_has_heap_property);
@@ -221,7 +240,7 @@ binaryheap_replace_first(binaryheap *heap, Datum d)
static void
sift_up(binaryheap *heap, int node_off)
{
- Datum node_val = heap->bh_nodes[node_off];
+ bh_node_type node_val = heap->bh_nodes[node_off];
/*
* Within the loop, the node_off'th array entry is a "hole" that
@@ -232,7 +251,7 @@ sift_up(binaryheap *heap, int node_off)
{
int cmp;
int parent_off;
- Datum parent_val;
+ bh_node_type parent_val;
/*
* If this node is smaller than its parent, the heap condition is
@@ -264,7 +283,7 @@ sift_up(binaryheap *heap, int node_off)
static void
sift_down(binaryheap *heap, int node_off)
{
- Datum node_val = heap->bh_nodes[node_off];
+ bh_node_type node_val = heap->bh_nodes[node_off];
/*
* Within the loop, the node_off'th array entry is a "hole" that
diff --git a/src/common/meson.build b/src/common/meson.build
index 53942a9a61..3b97497d1a 100644
--- a/src/common/meson.build
+++ b/src/common/meson.build
@@ -3,6 +3,7 @@
common_sources = files(
'archive.c',
'base64.c',
+ 'binaryheap.c',
'checksum_helper.c',
'compression.c',
'controldata_utils.c',
diff --git a/src/include/lib/binaryheap.h b/src/include/lib/binaryheap.h
index 52f7b06b25..3647aeae65 100644
--- a/src/include/lib/binaryheap.h
+++ b/src/include/lib/binaryheap.h
@@ -11,11 +11,23 @@
#ifndef BINARYHEAP_H
#define BINARYHEAP_H
+/*
+ * We provide a Datum-based API for backend code and a void *-based API for
+ * frontend code (since the Datum definitions are not available to frontend
+ * code). You should typically avoid using bh_node_type directly and instead
+ * use Datum or void * as appropriate.
+ */
+#ifdef FRONTEND
+typedef void *bh_node_type;
+#else
+typedef Datum bh_node_type;
+#endif
+
/*
* For a max-heap, the comparator must return <0 iff a < b, 0 iff a == b,
* and >0 iff a > b. For a min-heap, the conditions are reversed.
*/
-typedef int (*binaryheap_comparator) (Datum a, Datum b, void *arg);
+typedef int (*binaryheap_comparator) (bh_node_type a, bh_node_type b, void *arg);
/*
* binaryheap
@@ -34,7 +46,7 @@ typedef struct binaryheap
bool bh_has_heap_property; /* debugging cross-check */
binaryheap_comparator bh_compare;
void *bh_arg;
- Datum bh_nodes[FLEXIBLE_ARRAY_MEMBER];
+ bh_node_type bh_nodes[FLEXIBLE_ARRAY_MEMBER];
} binaryheap;
extern binaryheap *binaryheap_allocate(int capacity,
@@ -42,12 +54,12 @@ extern binaryheap *binaryheap_allocate(int capacity,
void *arg);
extern void binaryheap_reset(binaryheap *heap);
extern void binaryheap_free(binaryheap *heap);
-extern void binaryheap_add_unordered(binaryheap *heap, Datum d);
+extern void binaryheap_add_unordered(binaryheap *heap, bh_node_type d);
extern void binaryheap_build(binaryheap *heap);
-extern void binaryheap_add(binaryheap *heap, Datum d);
-extern Datum binaryheap_first(binaryheap *heap);
-extern Datum binaryheap_remove_first(binaryheap *heap);
-extern void binaryheap_replace_first(binaryheap *heap, Datum d);
+extern void binaryheap_add(binaryheap *heap, bh_node_type d);
+extern bh_node_type binaryheap_first(binaryheap *heap);
+extern bh_node_type binaryheap_remove_first(binaryheap *heap);
+extern void binaryheap_replace_first(binaryheap *heap, bh_node_type d);
#define binaryheap_empty(h) ((h)->bh_size == 0)
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index f3d8a2a855..b5bbdd1608 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -3198,6 +3198,7 @@ bbstreamer_tar_archiver
bbstreamer_tar_parser
bbstreamer_zstd_frame
bgworker_main_type
+bh_node_type
binaryheap
binaryheap_comparator
bitmapword
--
2.25.1
--gBBFr7Ir9EOA20Yy
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v8-0002-Add-function-for-removing-arbitrary-nodes-in-bina.patch"
^ permalink raw reply [nested|flat] 12+ messages in thread
* [PATCH v5 1/4] Add pgstat_report_anytime_stat() for periodic stats flushing
@ 2026-01-05 09:41 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 12+ messages in thread
From: Bertrand Drouvot @ 2026-01-05 09:41 UTC (permalink / raw)
Long running transactions can accumulate significant statistics (WAL, IO, ...)
that remain unflushed until the transaction ends. This delays visibility of
resource usage in monitoring views like pg_stat_io and pg_stat_wal.
This commit introduces pgstat_report_anytime_stat(), which flushes
non transactional statistics even inside active transactions. A new timeout
handler fires every second (if enabled while adding pending stats) to call this
function, ensuring timely stats visibility without waiting for transaction completion.
Implementation details:
- Add PgStat_FlushMode enum to classify stats kinds:
* FLUSH_ANYTIME: Stats that can always be flushed (WAL, IO, ...)
* FLUSH_AT_TXN_BOUNDARY: Stats requiring transaction boundaries
- Modify pgstat_flush_pending_entries() and pgstat_flush_fixed_stats()
to accept a boolean anytime_only parameter:
* When false: flushes all stats (existing behavior)
* When true: flushes only FLUSH_ANYTIME stats and skips FLUSH_AT_TXN_BOUNDARY stats
- This relies on the existing PGSTAT_MIN_INTERVAL to fire every 1 second, calling
pgstat_report_anytime_stat(false)
The force parameter in pgstat_report_anytime_stat() is currently unused (always
called with force=false) but reserved for future use cases requiring immediate
flushing.
---
src/backend/access/transam/xlog.c | 9 ++
src/backend/postmaster/bgwriter.c | 9 +-
src/backend/postmaster/checkpointer.c | 10 +-
src/backend/postmaster/startup.c | 2 +
src/backend/postmaster/walsummarizer.c | 9 +-
src/backend/postmaster/walwriter.c | 9 +-
src/backend/replication/walreceiver.c | 9 +-
src/backend/tcop/postgres.c | 12 ++
src/backend/utils/activity/pgstat.c | 118 ++++++++++++++++----
src/backend/utils/activity/pgstat_backend.c | 9 ++
src/backend/utils/activity/pgstat_io.c | 5 +
src/backend/utils/activity/pgstat_slru.c | 5 +
src/backend/utils/init/globals.c | 1 +
src/backend/utils/init/postinit.c | 3 +
src/include/miscadmin.h | 1 +
src/include/pgstat.h | 4 +
src/include/utils/pgstat_internal.h | 21 ++++
src/include/utils/timeout.h | 1 +
src/tools/pgindent/typedefs.list | 1 +
19 files changed, 213 insertions(+), 25 deletions(-)
5.5% src/backend/access/transam/
15.3% src/backend/postmaster/
3.4% src/backend/replication/
3.8% src/backend/tcop/
57.0% src/backend/utils/activity/
9.2% src/include/utils/
5.3% src/
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 13ec6225b85..9503aea5b4d 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -1085,6 +1085,10 @@ XLogInsertRecord(XLogRecData *rdata,
pgWalUsage.wal_fpi += num_fpi;
pgWalUsage.wal_fpi_bytes += fpi_bytes;
+ /* Schedule next anytime stats update timeout */
+ if (IsUnderPostmaster && !get_timeout_active(ANYTIME_STATS_UPDATE_TIMEOUT))
+ enable_timeout_after(ANYTIME_STATS_UPDATE_TIMEOUT, PGSTAT_MIN_INTERVAL);
+
/* Required for the flush of pending stats WAL data */
pgstat_report_fixed = true;
}
@@ -2066,6 +2070,11 @@ AdvanceXLInsertBuffer(XLogRecPtr upto, TimeLineID tli, bool opportunistic)
pgWalUsage.wal_buffers_full++;
TRACE_POSTGRESQL_WAL_BUFFER_WRITE_DIRTY_DONE();
+ /* Schedule next anytime stats update timeout */
+ if (IsUnderPostmaster && !get_timeout_active(ANYTIME_STATS_UPDATE_TIMEOUT))
+ enable_timeout_after(ANYTIME_STATS_UPDATE_TIMEOUT,
+ PGSTAT_MIN_INTERVAL);
+
/*
* Required for the flush of pending stats WAL data, per
* update of pgWalUsage.
diff --git a/src/backend/postmaster/bgwriter.c b/src/backend/postmaster/bgwriter.c
index 80e3088fc7e..ab5d0645026 100644
--- a/src/backend/postmaster/bgwriter.c
+++ b/src/backend/postmaster/bgwriter.c
@@ -49,7 +49,9 @@
#include "storage/smgr.h"
#include "storage/standby.h"
#include "utils/memutils.h"
+#include "utils/pgstat_internal.h"
#include "utils/resowner.h"
+#include "utils/timeout.h"
#include "utils/timestamp.h"
/*
@@ -104,7 +106,7 @@ BackgroundWriterMain(const void *startup_data, size_t startup_data_len)
pqsignal(SIGINT, SIG_IGN);
pqsignal(SIGTERM, SignalHandlerForShutdownRequest);
/* SIGQUIT handler was already set up by InitPostmasterChild */
- pqsignal(SIGALRM, SIG_IGN);
+ InitializeTimeouts(); /* establishes SIGALRM handler */
pqsignal(SIGPIPE, SIG_IGN);
pqsignal(SIGUSR1, procsignal_sigusr1_handler);
pqsignal(SIGUSR2, SIG_IGN);
@@ -114,6 +116,11 @@ BackgroundWriterMain(const void *startup_data, size_t startup_data_len)
*/
pqsignal(SIGCHLD, SIG_DFL);
+ /*
+ * Register timeouts needed
+ */
+ RegisterTimeout(ANYTIME_STATS_UPDATE_TIMEOUT, AnytimeStatsUpdateTimeoutHandler);
+
/*
* We just started, assume there has been either a shutdown or
* end-of-recovery snapshot.
diff --git a/src/backend/postmaster/checkpointer.c b/src/backend/postmaster/checkpointer.c
index 6482c21b8f9..6e187315613 100644
--- a/src/backend/postmaster/checkpointer.c
+++ b/src/backend/postmaster/checkpointer.c
@@ -66,8 +66,9 @@
#include "utils/acl.h"
#include "utils/guc.h"
#include "utils/memutils.h"
+#include "utils/pgstat_internal.h"
#include "utils/resowner.h"
-
+#include "utils/timeout.h"
/*----------
* Shared memory area for communication between checkpointer and backends
@@ -216,7 +217,7 @@ CheckpointerMain(const void *startup_data, size_t startup_data_len)
pqsignal(SIGINT, ReqShutdownXLOG);
pqsignal(SIGTERM, SIG_IGN); /* ignore SIGTERM */
/* SIGQUIT handler was already set up by InitPostmasterChild */
- pqsignal(SIGALRM, SIG_IGN);
+ InitializeTimeouts(); /* establishes SIGALRM handler */
pqsignal(SIGPIPE, SIG_IGN);
pqsignal(SIGUSR1, procsignal_sigusr1_handler);
pqsignal(SIGUSR2, SignalHandlerForShutdownRequest);
@@ -226,6 +227,11 @@ CheckpointerMain(const void *startup_data, size_t startup_data_len)
*/
pqsignal(SIGCHLD, SIG_DFL);
+ /*
+ * Register timeouts needed
+ */
+ RegisterTimeout(ANYTIME_STATS_UPDATE_TIMEOUT, AnytimeStatsUpdateTimeoutHandler);
+
/*
* Initialize so that first time-driven event happens at the correct time.
*/
diff --git a/src/backend/postmaster/startup.c b/src/backend/postmaster/startup.c
index a1a4f65f9a9..498d147f0da 100644
--- a/src/backend/postmaster/startup.c
+++ b/src/backend/postmaster/startup.c
@@ -32,6 +32,7 @@
#include "storage/standby.h"
#include "utils/guc.h"
#include "utils/memutils.h"
+#include "utils/pgstat_internal.h"
#include "utils/timeout.h"
@@ -246,6 +247,7 @@ StartupProcessMain(const void *startup_data, size_t startup_data_len)
RegisterTimeout(STANDBY_DEADLOCK_TIMEOUT, StandbyDeadLockHandler);
RegisterTimeout(STANDBY_TIMEOUT, StandbyTimeoutHandler);
RegisterTimeout(STANDBY_LOCK_TIMEOUT, StandbyLockTimeoutHandler);
+ RegisterTimeout(ANYTIME_STATS_UPDATE_TIMEOUT, AnytimeStatsUpdateTimeoutHandler);
/*
* Unblock signals (they were blocked when the postmaster forked us)
diff --git a/src/backend/postmaster/walsummarizer.c b/src/backend/postmaster/walsummarizer.c
index c3d56c866d3..cec5dfdb430 100644
--- a/src/backend/postmaster/walsummarizer.c
+++ b/src/backend/postmaster/walsummarizer.c
@@ -48,6 +48,8 @@
#include "storage/shmem.h"
#include "utils/guc.h"
#include "utils/memutils.h"
+#include "utils/pgstat_internal.h"
+#include "utils/timeout.h"
#include "utils/wait_event.h"
/*
@@ -250,7 +252,7 @@ WalSummarizerMain(const void *startup_data, size_t startup_data_len)
pqsignal(SIGINT, SignalHandlerForShutdownRequest);
pqsignal(SIGTERM, SignalHandlerForShutdownRequest);
/* SIGQUIT handler was already set up by InitPostmasterChild */
- pqsignal(SIGALRM, SIG_IGN);
+ InitializeTimeouts(); /* establishes SIGALRM handler */
pqsignal(SIGPIPE, SIG_IGN);
pqsignal(SIGUSR1, procsignal_sigusr1_handler);
pqsignal(SIGUSR2, SIG_IGN); /* not used */
@@ -272,6 +274,11 @@ WalSummarizerMain(const void *startup_data, size_t startup_data_len)
*/
pqsignal(SIGCHLD, SIG_DFL);
+ /*
+ * Register timeouts needed
+ */
+ RegisterTimeout(ANYTIME_STATS_UPDATE_TIMEOUT, AnytimeStatsUpdateTimeoutHandler);
+
/*
* If an exception is encountered, processing resumes here.
*/
diff --git a/src/backend/postmaster/walwriter.c b/src/backend/postmaster/walwriter.c
index 38ec8a4c8c7..7416ca703c9 100644
--- a/src/backend/postmaster/walwriter.c
+++ b/src/backend/postmaster/walwriter.c
@@ -61,7 +61,9 @@
#include "storage/smgr.h"
#include "utils/hsearch.h"
#include "utils/memutils.h"
+#include "utils/pgstat_internal.h"
#include "utils/resowner.h"
+#include "utils/timeout.h"
/*
@@ -107,7 +109,7 @@ WalWriterMain(const void *startup_data, size_t startup_data_len)
pqsignal(SIGINT, SignalHandlerForShutdownRequest);
pqsignal(SIGTERM, SignalHandlerForShutdownRequest);
/* SIGQUIT handler was already set up by InitPostmasterChild */
- pqsignal(SIGALRM, SIG_IGN);
+ InitializeTimeouts(); /* establishes SIGALRM handler */
pqsignal(SIGPIPE, SIG_IGN);
pqsignal(SIGUSR1, procsignal_sigusr1_handler);
pqsignal(SIGUSR2, SIG_IGN); /* not used */
@@ -117,6 +119,11 @@ WalWriterMain(const void *startup_data, size_t startup_data_len)
*/
pqsignal(SIGCHLD, SIG_DFL);
+ /*
+ * Register timeouts needed
+ */
+ RegisterTimeout(ANYTIME_STATS_UPDATE_TIMEOUT, AnytimeStatsUpdateTimeoutHandler);
+
/*
* Create a memory context that we will do all our work in. We do this so
* that we can reset the context during error recovery and thereby avoid
diff --git a/src/backend/replication/walreceiver.c b/src/backend/replication/walreceiver.c
index 8b99160ed0e..24d7ef795cb 100644
--- a/src/backend/replication/walreceiver.c
+++ b/src/backend/replication/walreceiver.c
@@ -77,7 +77,9 @@
#include "utils/builtins.h"
#include "utils/guc.h"
#include "utils/pg_lsn.h"
+#include "utils/pgstat_internal.h"
#include "utils/ps_status.h"
+#include "utils/timeout.h"
#include "utils/timestamp.h"
@@ -253,7 +255,7 @@ WalReceiverMain(const void *startup_data, size_t startup_data_len)
pqsignal(SIGINT, SIG_IGN);
pqsignal(SIGTERM, die); /* request shutdown */
/* SIGQUIT handler was already set up by InitPostmasterChild */
- pqsignal(SIGALRM, SIG_IGN);
+ InitializeTimeouts(); /* establishes SIGALRM handler */
pqsignal(SIGPIPE, SIG_IGN);
pqsignal(SIGUSR1, procsignal_sigusr1_handler);
pqsignal(SIGUSR2, SIG_IGN);
@@ -261,6 +263,11 @@ WalReceiverMain(const void *startup_data, size_t startup_data_len)
/* Reset some signals that are accepted by postmaster but not here */
pqsignal(SIGCHLD, SIG_DFL);
+ /*
+ * Register timeouts needed
+ */
+ RegisterTimeout(ANYTIME_STATS_UPDATE_TIMEOUT, AnytimeStatsUpdateTimeoutHandler);
+
/* Load the libpq-specific functions */
load_file("libpqwalreceiver", false);
if (WalReceiverFunctions == NULL)
diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c
index b4a8d2f3a1c..d19aa45400d 100644
--- a/src/backend/tcop/postgres.c
+++ b/src/backend/tcop/postgres.c
@@ -3530,6 +3530,18 @@ ProcessInterrupts(void)
pgstat_report_stat(true);
}
+ /*
+ * Flush stats outside of transaction boundary if the timeout fired.
+ * Unlike transactional stats, these can be flushed even inside a running
+ * transaction.
+ */
+ if (AnytimeStatsUpdateTimeoutPending)
+ {
+ AnytimeStatsUpdateTimeoutPending = false;
+
+ pgstat_report_anytime_stat(false);
+ }
+
if (ProcSignalBarrierPending)
ProcessProcSignalBarrier();
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index 11bb71cad5a..2c9454677e9 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -112,6 +112,7 @@
#include "utils/guc_hooks.h"
#include "utils/memutils.h"
#include "utils/pgstat_internal.h"
+#include "utils/timeout.h"
#include "utils/timestamp.h"
@@ -122,8 +123,6 @@
* ----------
*/
-/* minimum interval non-forced stats flushes.*/
-#define PGSTAT_MIN_INTERVAL 1000
/* how long until to block flushing pending stats updates */
#define PGSTAT_MAX_INTERVAL 60000
/* when to call pgstat_report_stat() again, even when idle */
@@ -187,7 +186,8 @@ static void pgstat_init_snapshot_fixed(void);
static void pgstat_reset_after_failure(void);
-static bool pgstat_flush_pending_entries(bool nowait);
+static bool pgstat_flush_pending_entries(bool nowait, bool anytime_only);
+static bool pgstat_flush_fixed_stats(bool nowait, bool anytime_only);
static void pgstat_prep_snapshot(void);
static void pgstat_build_snapshot(void);
@@ -288,6 +288,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = true,
+ .flush_mode = FLUSH_AT_TXN_BOUNDARY,
/* so pg_stat_database entries can be seen in all databases */
.accessed_across_databases = true,
@@ -305,6 +306,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = true,
+ .flush_mode = FLUSH_AT_TXN_BOUNDARY,
.shared_size = sizeof(PgStatShared_Relation),
.shared_data_off = offsetof(PgStatShared_Relation, stats),
@@ -321,6 +323,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = true,
+ .flush_mode = FLUSH_AT_TXN_BOUNDARY,
.shared_size = sizeof(PgStatShared_Function),
.shared_data_off = offsetof(PgStatShared_Function, stats),
@@ -336,6 +339,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = true,
+ .flush_mode = FLUSH_AT_TXN_BOUNDARY,
.accessed_across_databases = true,
@@ -353,6 +357,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = true,
+ .flush_mode = FLUSH_AT_TXN_BOUNDARY,
/* so pg_stat_subscription_stats entries can be seen in all databases */
.accessed_across_databases = true,
@@ -370,6 +375,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = false,
+ .flush_mode = FLUSH_ANYTIME,
.accessed_across_databases = true,
@@ -388,6 +394,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = true,
.write_to_file = true,
+ .flush_mode = FLUSH_ANYTIME,
.snapshot_ctl_off = offsetof(PgStat_Snapshot, archiver),
.shared_ctl_off = offsetof(PgStat_ShmemControl, archiver),
@@ -404,6 +411,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = true,
.write_to_file = true,
+ .flush_mode = FLUSH_ANYTIME,
.snapshot_ctl_off = offsetof(PgStat_Snapshot, bgwriter),
.shared_ctl_off = offsetof(PgStat_ShmemControl, bgwriter),
@@ -420,6 +428,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = true,
.write_to_file = true,
+ .flush_mode = FLUSH_ANYTIME,
.snapshot_ctl_off = offsetof(PgStat_Snapshot, checkpointer),
.shared_ctl_off = offsetof(PgStat_ShmemControl, checkpointer),
@@ -436,6 +445,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = true,
.write_to_file = true,
+ .flush_mode = FLUSH_ANYTIME,
.snapshot_ctl_off = offsetof(PgStat_Snapshot, io),
.shared_ctl_off = offsetof(PgStat_ShmemControl, io),
@@ -453,6 +463,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = true,
.write_to_file = true,
+ .flush_mode = FLUSH_ANYTIME,
.snapshot_ctl_off = offsetof(PgStat_Snapshot, slru),
.shared_ctl_off = offsetof(PgStat_ShmemControl, slru),
@@ -470,6 +481,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = true,
.write_to_file = true,
+ .flush_mode = FLUSH_ANYTIME,
.snapshot_ctl_off = offsetof(PgStat_Snapshot, wal),
.shared_ctl_off = offsetof(PgStat_ShmemControl, wal),
@@ -775,23 +787,11 @@ pgstat_report_stat(bool force)
partial_flush = false;
/* flush of variable-numbered stats tracked in pending entries list */
- partial_flush |= pgstat_flush_pending_entries(nowait);
+ partial_flush |= pgstat_flush_pending_entries(nowait, false);
/* flush of other stats kinds */
if (pgstat_report_fixed)
- {
- for (PgStat_Kind kind = PGSTAT_KIND_MIN; kind <= PGSTAT_KIND_MAX; kind++)
- {
- const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
-
- if (!kind_info)
- continue;
- if (!kind_info->flush_static_cb)
- continue;
-
- partial_flush |= kind_info->flush_static_cb(nowait);
- }
- }
+ partial_flush |= pgstat_flush_fixed_stats(nowait, false);
last_flush = now;
@@ -1293,12 +1293,18 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
entry_ref->pending = MemoryContextAllocZero(pgStatPendingContext, entrysize);
dlist_push_tail(&pgStatPending, &entry_ref->pending_node);
+
+ /* Schedule next anytime stats update timeout */
+ if (kind_info->flush_mode == FLUSH_ANYTIME && IsUnderPostmaster &&
+ !get_timeout_active(ANYTIME_STATS_UPDATE_TIMEOUT))
+ enable_timeout_after(ANYTIME_STATS_UPDATE_TIMEOUT, PGSTAT_MIN_INTERVAL);
}
return entry_ref;
@@ -1345,9 +1351,14 @@ pgstat_delete_pending_entry(PgStat_EntryRef *entry_ref)
/*
* Flush out pending variable-numbered stats.
+ *
+ * If anytime_only is true, only flushes FLUSH_ANYTIME entries.
+ * This is safe to call inside transactions.
+ *
+ * If anytime_only is false, flushes all entries.
*/
static bool
-pgstat_flush_pending_entries(bool nowait)
+pgstat_flush_pending_entries(bool nowait, bool anytime_only)
{
bool have_pending = false;
dlist_node *cur = NULL;
@@ -1377,6 +1388,20 @@ pgstat_flush_pending_entries(bool nowait)
Assert(!kind_info->fixed_amount);
Assert(kind_info->flush_pending_cb != NULL);
+ /* Skip transactional stats if we're in anytime_only mode */
+ if (anytime_only && kind_info->flush_mode == FLUSH_AT_TXN_BOUNDARY)
+ {
+ have_pending = true;
+
+ if (dlist_has_next(&pgStatPending, cur))
+ next = dlist_next_node(&pgStatPending, cur);
+ else
+ next = NULL;
+
+ cur = next;
+ continue;
+ }
+
/* flush the stats, if possible */
did_flush = kind_info->flush_pending_cb(entry_ref, nowait);
@@ -1402,6 +1427,33 @@ pgstat_flush_pending_entries(bool nowait)
return have_pending;
}
+/*
+ * Flush fixed-amount stats.
+ *
+ * If anytime_only is true, only flushes FLUSH_ANYTIME stats (safe inside transactions).
+ * If anytime_only is false, flushes all stats with flush_static_cb.
+ */
+static bool
+pgstat_flush_fixed_stats(bool nowait, bool anytime_only)
+{
+ bool partial_flush = false;
+
+ for (PgStat_Kind kind = PGSTAT_KIND_MIN; kind <= PGSTAT_KIND_MAX; kind++)
+ {
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (!kind_info || !kind_info->flush_static_cb)
+ continue;
+
+ /* Skip transactional stats if we're in anytime_only mode */
+ if (anytime_only && kind_info->flush_mode == FLUSH_AT_TXN_BOUNDARY)
+ continue;
+
+ partial_flush |= kind_info->flush_static_cb(nowait);
+ }
+
+ return partial_flush;
+}
/* ------------------------------------------------------------
* Helper / infrastructure functions
@@ -2119,3 +2171,31 @@ assign_stats_fetch_consistency(int newval, void *extra)
if (pgstat_fetch_consistency != newval)
force_stats_snapshot_clear = true;
}
+
+/*
+ * Flushes only FLUSH_ANYTIME stats using non-blocking locks. Transactional
+ * stats (FLUSH_AT_TXN_BOUNDARY) remain pending until transaction boundary.
+ * Safe to call inside transactions.
+ */
+void
+pgstat_report_anytime_stat(bool force)
+{
+ bool nowait = !force;
+
+ pgstat_assert_is_up();
+
+ /* Flush stats outside of transaction boundary */
+ pgstat_flush_pending_entries(nowait, true);
+ pgstat_flush_fixed_stats(nowait, true);
+}
+
+/*
+ * Timeout handler for flushing non-transactional stats.
+ */
+void
+AnytimeStatsUpdateTimeoutHandler(void)
+{
+ AnytimeStatsUpdateTimeoutPending = true;
+ InterruptPending = true;
+ SetLatch(MyLatch);
+}
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 1350f5f62f1..9dcb24db975 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -31,6 +31,7 @@
#include "storage/procarray.h"
#include "utils/memutils.h"
#include "utils/pgstat_internal.h"
+#include "utils/timeout.h"
/*
* Backend statistics counts waiting to be flushed out. These counters may be
@@ -66,6 +67,10 @@ pgstat_count_backend_io_op_time(IOObject io_object, IOContext io_context,
INSTR_TIME_ADD(PendingBackendStats.pending_io.pending_times[io_object][io_context][io_op],
io_time);
+ /* Schedule next anytime stats update timeout */
+ if (IsUnderPostmaster && !get_timeout_active(ANYTIME_STATS_UPDATE_TIMEOUT))
+ enable_timeout_after(ANYTIME_STATS_UPDATE_TIMEOUT, PGSTAT_MIN_INTERVAL);
+
backend_has_iostats = true;
pgstat_report_fixed = true;
}
@@ -82,6 +87,10 @@ pgstat_count_backend_io_op(IOObject io_object, IOContext io_context,
PendingBackendStats.pending_io.counts[io_object][io_context][io_op] += cnt;
PendingBackendStats.pending_io.bytes[io_object][io_context][io_op] += bytes;
+ /* Schedule next anytime stats update timeout */
+ if (IsUnderPostmaster && !get_timeout_active(ANYTIME_STATS_UPDATE_TIMEOUT))
+ enable_timeout_after(ANYTIME_STATS_UPDATE_TIMEOUT, PGSTAT_MIN_INTERVAL);
+
backend_has_iostats = true;
pgstat_report_fixed = true;
}
diff --git a/src/backend/utils/activity/pgstat_io.c b/src/backend/utils/activity/pgstat_io.c
index 28de24538dc..53dbf2a514b 100644
--- a/src/backend/utils/activity/pgstat_io.c
+++ b/src/backend/utils/activity/pgstat_io.c
@@ -19,6 +19,7 @@
#include "executor/instrument.h"
#include "storage/bufmgr.h"
#include "utils/pgstat_internal.h"
+#include "utils/timeout.h"
static PgStat_PendingIO PendingIOStats;
static bool have_iostats = false;
@@ -79,6 +80,10 @@ pgstat_count_io_op(IOObject io_object, IOContext io_context, IOOp io_op,
/* Add the per-backend counts */
pgstat_count_backend_io_op(io_object, io_context, io_op, cnt, bytes);
+ /* Schedule next anytime stats update timeout */
+ if (IsUnderPostmaster && !get_timeout_active(ANYTIME_STATS_UPDATE_TIMEOUT))
+ enable_timeout_after(ANYTIME_STATS_UPDATE_TIMEOUT, PGSTAT_MIN_INTERVAL);
+
have_iostats = true;
pgstat_report_fixed = true;
}
diff --git a/src/backend/utils/activity/pgstat_slru.c b/src/backend/utils/activity/pgstat_slru.c
index 2190f388eae..1d16cde1889 100644
--- a/src/backend/utils/activity/pgstat_slru.c
+++ b/src/backend/utils/activity/pgstat_slru.c
@@ -19,6 +19,7 @@
#include "utils/pgstat_internal.h"
#include "utils/timestamp.h"
+#include "utils/timeout.h"
static inline PgStat_SLRUStats *get_slru_entry(int slru_idx);
@@ -223,6 +224,10 @@ get_slru_entry(int slru_idx)
Assert((slru_idx >= 0) && (slru_idx < SLRU_NUM_ELEMENTS));
+ /* Schedule next anytime stats update timeout */
+ if (IsUnderPostmaster && !get_timeout_active(ANYTIME_STATS_UPDATE_TIMEOUT))
+ enable_timeout_after(ANYTIME_STATS_UPDATE_TIMEOUT, PGSTAT_MIN_INTERVAL);
+
have_slrustats = true;
pgstat_report_fixed = true;
diff --git a/src/backend/utils/init/globals.c b/src/backend/utils/init/globals.c
index 36ad708b360..ad44826c39e 100644
--- a/src/backend/utils/init/globals.c
+++ b/src/backend/utils/init/globals.c
@@ -40,6 +40,7 @@ volatile sig_atomic_t IdleSessionTimeoutPending = false;
volatile sig_atomic_t ProcSignalBarrierPending = false;
volatile sig_atomic_t LogMemoryContextPending = false;
volatile sig_atomic_t IdleStatsUpdateTimeoutPending = false;
+volatile sig_atomic_t AnytimeStatsUpdateTimeoutPending = false;
volatile uint32 InterruptHoldoffCount = 0;
volatile uint32 QueryCancelHoldoffCount = 0;
volatile uint32 CritSectionCount = 0;
diff --git a/src/backend/utils/init/postinit.c b/src/backend/utils/init/postinit.c
index 3f401faf3de..f45365f47f7 100644
--- a/src/backend/utils/init/postinit.c
+++ b/src/backend/utils/init/postinit.c
@@ -64,6 +64,7 @@
#include "utils/injection_point.h"
#include "utils/memutils.h"
#include "utils/pg_locale.h"
+#include "utils/pgstat_internal.h"
#include "utils/portal.h"
#include "utils/ps_status.h"
#include "utils/snapmgr.h"
@@ -765,6 +766,8 @@ InitPostgres(const char *in_dbname, Oid dboid,
RegisterTimeout(CLIENT_CONNECTION_CHECK_TIMEOUT, ClientCheckTimeoutHandler);
RegisterTimeout(IDLE_STATS_UPDATE_TIMEOUT,
IdleStatsUpdateTimeoutHandler);
+ RegisterTimeout(ANYTIME_STATS_UPDATE_TIMEOUT,
+ AnytimeStatsUpdateTimeoutHandler);
}
/*
diff --git a/src/include/miscadmin.h b/src/include/miscadmin.h
index db559b39c4d..8aeb9628871 100644
--- a/src/include/miscadmin.h
+++ b/src/include/miscadmin.h
@@ -96,6 +96,7 @@ extern PGDLLIMPORT volatile sig_atomic_t IdleSessionTimeoutPending;
extern PGDLLIMPORT volatile sig_atomic_t ProcSignalBarrierPending;
extern PGDLLIMPORT volatile sig_atomic_t LogMemoryContextPending;
extern PGDLLIMPORT volatile sig_atomic_t IdleStatsUpdateTimeoutPending;
+extern PGDLLIMPORT volatile sig_atomic_t AnytimeStatsUpdateTimeoutPending;
extern PGDLLIMPORT volatile sig_atomic_t CheckClientConnectionPending;
extern PGDLLIMPORT volatile sig_atomic_t ClientConnectionLost;
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index fff7ecc2533..1651f16f966 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -35,6 +35,9 @@
/* Default directory to store temporary statistics data in */
#define PG_STAT_TMP_DIR "pg_stat_tmp"
+/* Minimum interval non-forced stats flushes */
+#define PGSTAT_MIN_INTERVAL 1000
+
/* Values for track_functions GUC variable --- order is significant! */
typedef enum TrackFunctionsLevel
{
@@ -533,6 +536,7 @@ extern void pgstat_initialize(void);
/* Functions called from backends */
extern long pgstat_report_stat(bool force);
+extern void pgstat_report_anytime_stat(bool force);
extern void pgstat_force_next_flush(void);
extern void pgstat_reset_counters(void);
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 9b8fbae00ed..a9190078d0e 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -224,6 +224,19 @@ typedef struct PgStat_SubXactStatus
PgStat_TableXactStatus *first; /* head of list for this subxact */
} PgStat_SubXactStatus;
+/*
+ * Flush mode for statistics kinds.
+ *
+ * FLUSH_AT_TXN_BOUNDARY has to be the first because we want it to be the
+ * default value.
+ */
+typedef enum PgStat_FlushMode
+{
+ FLUSH_AT_TXN_BOUNDARY, /* All fields can only be flushed at
+ * transaction boundary */
+ FLUSH_ANYTIME, /* All fields can be flushed anytime,
+ * including within transactions */
+} PgStat_FlushMode;
/*
* Metadata for a specific kind of statistics.
@@ -251,6 +264,13 @@ typedef struct PgStat_KindInfo
*/
bool track_entry_count:1;
+ /*
+ * Some stats have to be updated only at transaction boundaries (such as
+ * tuples_inserted updated, deleted), so it's very important to set the
+ * right flush mode (FLUSH_AT_TXN_BOUNDARY being the default).
+ */
+ PgStat_FlushMode flush_mode;
+
/*
* The size of an entry in the shared stats hash table (pointed to by
* PgStatShared_HashEntry->body). For fixed-numbered statistics, this is
@@ -677,6 +697,7 @@ extern PgStat_EntryRef *pgstat_fetch_pending_entry(PgStat_Kind kind,
extern void *pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid);
extern void pgstat_snapshot_fixed(PgStat_Kind kind);
+extern void AnytimeStatsUpdateTimeoutHandler(void);
/*
diff --git a/src/include/utils/timeout.h b/src/include/utils/timeout.h
index 0965b590b34..10723bb664c 100644
--- a/src/include/utils/timeout.h
+++ b/src/include/utils/timeout.h
@@ -35,6 +35,7 @@ typedef enum TimeoutId
IDLE_SESSION_TIMEOUT,
IDLE_STATS_UPDATE_TIMEOUT,
CLIENT_CONNECTION_CHECK_TIMEOUT,
+ ANYTIME_STATS_UPDATE_TIMEOUT,
STARTUP_PROGRESS_TIMEOUT,
/* First user-definable timeout reason */
USER_TIMEOUT,
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 9f5ee8fd482..860f835c088 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -2268,6 +2268,7 @@ PgStat_Counter
PgStat_EntryRef
PgStat_EntryRefHashEntry
PgStat_FetchConsistency
+PgStat_FlushMode
PgStat_FunctionCallUsage
PgStat_FunctionCounts
PgStat_HashKey
--
2.34.1
--WLtTrIUEfQDmERxy
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v5-0002-Add-GUC-to-specify-non-transactional-statistics-f.patch"
^ permalink raw reply [nested|flat] 12+ messages in thread
* [PATCH v6 1/5] Add pgstat_report_anytime_stat() for periodic stats flushing
@ 2026-01-05 09:41 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 12+ messages in thread
From: Bertrand Drouvot @ 2026-01-05 09:41 UTC (permalink / raw)
Long running transactions can accumulate significant statistics (WAL, IO, ...)
that remain unflushed until the transaction ends. This delays visibility of
resource usage in monitoring views like pg_stat_io and pg_stat_wal and produces
spikes when flushed.
This commit introduces pgstat_report_anytime_stat(), which flushes
non transactional statistics even inside active transactions. A new timeout
handler fires every second (if enabled while adding pending stats) to call this
function, ensuring timely stats visibility without waiting for transaction completion.
Implementation details:
- Add PgStat_FlushMode enum to classify stats kinds:
* FLUSH_ANYTIME: Stats that can always be flushed (WAL, IO, ...)
* FLUSH_AT_TXN_BOUNDARY: Stats requiring transaction boundaries
- Modify pgstat_flush_pending_entries() and pgstat_flush_fixed_stats()
to accept a boolean anytime_only parameter:
* When false: flushes all stats (existing behavior)
* When true: flushes only FLUSH_ANYTIME stats and skips FLUSH_AT_TXN_BOUNDARY stats
- The flush_pending_cb and flush_static_cb callbacks now receive an anytime_only
boolean parameter. Most of the time it's not used (except for assertions), but it's
preparatory work for moving the relations stats to anytime (without introducin
a new callback).
- Add pgstat_schedule_anytime_update() macro to schedule the next anytime flush,
relying on PGSTAT_MIN_INTERVAL
The force parameter in pgstat_report_anytime_stat() is currently unused (always
called with force=false) but reserved for future use cases requiring immediate
flushing.
---
src/backend/access/transam/xlog.c | 6 +
src/backend/postmaster/bgwriter.c | 9 +-
src/backend/postmaster/checkpointer.c | 10 +-
src/backend/postmaster/startup.c | 2 +
src/backend/postmaster/walsummarizer.c | 9 +-
src/backend/postmaster/walwriter.c | 9 +-
src/backend/replication/walreceiver.c | 9 +-
src/backend/replication/walsender.c | 8 +-
src/backend/tcop/postgres.c | 12 ++
src/backend/utils/activity/pgstat.c | 112 ++++++++++++++----
src/backend/utils/activity/pgstat_backend.c | 13 +-
src/backend/utils/activity/pgstat_bgwriter.c | 2 +-
.../utils/activity/pgstat_checkpointer.c | 2 +-
src/backend/utils/activity/pgstat_database.c | 2 +-
src/backend/utils/activity/pgstat_function.c | 4 +-
src/backend/utils/activity/pgstat_io.c | 10 +-
src/backend/utils/activity/pgstat_relation.c | 12 +-
src/backend/utils/activity/pgstat_slru.c | 6 +-
.../utils/activity/pgstat_subscription.c | 4 +-
src/backend/utils/activity/pgstat_wal.c | 10 +-
src/backend/utils/init/globals.c | 1 +
src/backend/utils/init/postinit.c | 3 +
src/include/miscadmin.h | 1 +
src/include/pgstat.h | 16 +++
src/include/utils/pgstat_internal.h | 52 ++++++--
src/include/utils/timeout.h | 1 +
.../test_custom_stats/test_custom_var_stats.c | 4 +-
src/tools/pgindent/typedefs.list | 1 +
28 files changed, 264 insertions(+), 66 deletions(-)
10.8% src/backend/postmaster/
6.0% src/backend/replication/
50.7% src/backend/utils/activity/
6.0% src/backend/
19.3% src/include/utils/
5.6% src/include/
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 13ec6225b85..d01b11c7470 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -1085,6 +1085,9 @@ XLogInsertRecord(XLogRecData *rdata,
pgWalUsage.wal_fpi += num_fpi;
pgWalUsage.wal_fpi_bytes += fpi_bytes;
+ /* Schedule next anytime stats update timeout */
+ pgstat_schedule_anytime_update();
+
/* Required for the flush of pending stats WAL data */
pgstat_report_fixed = true;
}
@@ -2066,6 +2069,9 @@ AdvanceXLInsertBuffer(XLogRecPtr upto, TimeLineID tli, bool opportunistic)
pgWalUsage.wal_buffers_full++;
TRACE_POSTGRESQL_WAL_BUFFER_WRITE_DIRTY_DONE();
+ /* Schedule next anytime stats update timeout */
+ pgstat_schedule_anytime_update();
+
/*
* Required for the flush of pending stats WAL data, per
* update of pgWalUsage.
diff --git a/src/backend/postmaster/bgwriter.c b/src/backend/postmaster/bgwriter.c
index 0956bd39a85..059c601c3b8 100644
--- a/src/backend/postmaster/bgwriter.c
+++ b/src/backend/postmaster/bgwriter.c
@@ -49,7 +49,9 @@
#include "storage/smgr.h"
#include "storage/standby.h"
#include "utils/memutils.h"
+#include "utils/pgstat_internal.h"
#include "utils/resowner.h"
+#include "utils/timeout.h"
#include "utils/timestamp.h"
/*
@@ -103,7 +105,7 @@ BackgroundWriterMain(const void *startup_data, size_t startup_data_len)
pqsignal(SIGINT, SIG_IGN);
pqsignal(SIGTERM, SignalHandlerForShutdownRequest);
/* SIGQUIT handler was already set up by InitPostmasterChild */
- pqsignal(SIGALRM, SIG_IGN);
+ InitializeTimeouts(); /* establishes SIGALRM handler */
pqsignal(SIGPIPE, SIG_IGN);
pqsignal(SIGUSR1, procsignal_sigusr1_handler);
pqsignal(SIGUSR2, SIG_IGN);
@@ -113,6 +115,11 @@ BackgroundWriterMain(const void *startup_data, size_t startup_data_len)
*/
pqsignal(SIGCHLD, SIG_DFL);
+ /*
+ * Register timeouts needed
+ */
+ RegisterTimeout(ANYTIME_STATS_UPDATE_TIMEOUT, AnytimeStatsUpdateTimeoutHandler);
+
/*
* We just started, assume there has been either a shutdown or
* end-of-recovery snapshot.
diff --git a/src/backend/postmaster/checkpointer.c b/src/backend/postmaster/checkpointer.c
index e03c19123bc..e11c4b099c8 100644
--- a/src/backend/postmaster/checkpointer.c
+++ b/src/backend/postmaster/checkpointer.c
@@ -66,8 +66,9 @@
#include "utils/acl.h"
#include "utils/guc.h"
#include "utils/memutils.h"
+#include "utils/pgstat_internal.h"
#include "utils/resowner.h"
-
+#include "utils/timeout.h"
/*----------
* Shared memory area for communication between checkpointer and backends
@@ -215,7 +216,7 @@ CheckpointerMain(const void *startup_data, size_t startup_data_len)
pqsignal(SIGINT, ReqShutdownXLOG);
pqsignal(SIGTERM, SIG_IGN); /* ignore SIGTERM */
/* SIGQUIT handler was already set up by InitPostmasterChild */
- pqsignal(SIGALRM, SIG_IGN);
+ InitializeTimeouts(); /* establishes SIGALRM handler */
pqsignal(SIGPIPE, SIG_IGN);
pqsignal(SIGUSR1, procsignal_sigusr1_handler);
pqsignal(SIGUSR2, SignalHandlerForShutdownRequest);
@@ -225,6 +226,11 @@ CheckpointerMain(const void *startup_data, size_t startup_data_len)
*/
pqsignal(SIGCHLD, SIG_DFL);
+ /*
+ * Register timeouts needed
+ */
+ RegisterTimeout(ANYTIME_STATS_UPDATE_TIMEOUT, AnytimeStatsUpdateTimeoutHandler);
+
/*
* Initialize so that first time-driven event happens at the correct time.
*/
diff --git a/src/backend/postmaster/startup.c b/src/backend/postmaster/startup.c
index cdbe53dd262..4954fe425b7 100644
--- a/src/backend/postmaster/startup.c
+++ b/src/backend/postmaster/startup.c
@@ -32,6 +32,7 @@
#include "storage/standby.h"
#include "utils/guc.h"
#include "utils/memutils.h"
+#include "utils/pgstat_internal.h"
#include "utils/timeout.h"
@@ -245,6 +246,7 @@ StartupProcessMain(const void *startup_data, size_t startup_data_len)
RegisterTimeout(STANDBY_DEADLOCK_TIMEOUT, StandbyDeadLockHandler);
RegisterTimeout(STANDBY_TIMEOUT, StandbyTimeoutHandler);
RegisterTimeout(STANDBY_LOCK_TIMEOUT, StandbyLockTimeoutHandler);
+ RegisterTimeout(ANYTIME_STATS_UPDATE_TIMEOUT, AnytimeStatsUpdateTimeoutHandler);
/*
* Unblock signals (they were blocked when the postmaster forked us)
diff --git a/src/backend/postmaster/walsummarizer.c b/src/backend/postmaster/walsummarizer.c
index 2d8f57099fd..9f8ef8159d1 100644
--- a/src/backend/postmaster/walsummarizer.c
+++ b/src/backend/postmaster/walsummarizer.c
@@ -48,6 +48,8 @@
#include "storage/shmem.h"
#include "utils/guc.h"
#include "utils/memutils.h"
+#include "utils/pgstat_internal.h"
+#include "utils/timeout.h"
#include "utils/wait_event.h"
/*
@@ -249,7 +251,7 @@ WalSummarizerMain(const void *startup_data, size_t startup_data_len)
pqsignal(SIGINT, SignalHandlerForShutdownRequest);
pqsignal(SIGTERM, SignalHandlerForShutdownRequest);
/* SIGQUIT handler was already set up by InitPostmasterChild */
- pqsignal(SIGALRM, SIG_IGN);
+ InitializeTimeouts(); /* establishes SIGALRM handler */
pqsignal(SIGPIPE, SIG_IGN);
pqsignal(SIGUSR1, procsignal_sigusr1_handler);
pqsignal(SIGUSR2, SIG_IGN); /* not used */
@@ -271,6 +273,11 @@ WalSummarizerMain(const void *startup_data, size_t startup_data_len)
*/
pqsignal(SIGCHLD, SIG_DFL);
+ /*
+ * Register timeouts needed
+ */
+ RegisterTimeout(ANYTIME_STATS_UPDATE_TIMEOUT, AnytimeStatsUpdateTimeoutHandler);
+
/*
* If an exception is encountered, processing resumes here.
*/
diff --git a/src/backend/postmaster/walwriter.c b/src/backend/postmaster/walwriter.c
index 23e79a32345..ded0f250288 100644
--- a/src/backend/postmaster/walwriter.c
+++ b/src/backend/postmaster/walwriter.c
@@ -61,7 +61,9 @@
#include "storage/smgr.h"
#include "utils/hsearch.h"
#include "utils/memutils.h"
+#include "utils/pgstat_internal.h"
#include "utils/resowner.h"
+#include "utils/timeout.h"
/*
@@ -106,7 +108,7 @@ WalWriterMain(const void *startup_data, size_t startup_data_len)
pqsignal(SIGINT, SignalHandlerForShutdownRequest);
pqsignal(SIGTERM, SignalHandlerForShutdownRequest);
/* SIGQUIT handler was already set up by InitPostmasterChild */
- pqsignal(SIGALRM, SIG_IGN);
+ InitializeTimeouts(); /* establishes SIGALRM handler */
pqsignal(SIGPIPE, SIG_IGN);
pqsignal(SIGUSR1, procsignal_sigusr1_handler);
pqsignal(SIGUSR2, SIG_IGN); /* not used */
@@ -116,6 +118,11 @@ WalWriterMain(const void *startup_data, size_t startup_data_len)
*/
pqsignal(SIGCHLD, SIG_DFL);
+ /*
+ * Register timeouts needed
+ */
+ RegisterTimeout(ANYTIME_STATS_UPDATE_TIMEOUT, AnytimeStatsUpdateTimeoutHandler);
+
/*
* Create a memory context that we will do all our work in. We do this so
* that we can reset the context during error recovery and thereby avoid
diff --git a/src/backend/replication/walreceiver.c b/src/backend/replication/walreceiver.c
index 10e64a7d1f4..11b7c114d3b 100644
--- a/src/backend/replication/walreceiver.c
+++ b/src/backend/replication/walreceiver.c
@@ -77,7 +77,9 @@
#include "utils/builtins.h"
#include "utils/guc.h"
#include "utils/pg_lsn.h"
+#include "utils/pgstat_internal.h"
#include "utils/ps_status.h"
+#include "utils/timeout.h"
#include "utils/timestamp.h"
@@ -252,7 +254,7 @@ WalReceiverMain(const void *startup_data, size_t startup_data_len)
pqsignal(SIGINT, SIG_IGN);
pqsignal(SIGTERM, die); /* request shutdown */
/* SIGQUIT handler was already set up by InitPostmasterChild */
- pqsignal(SIGALRM, SIG_IGN);
+ InitializeTimeouts(); /* establishes SIGALRM handler */
pqsignal(SIGPIPE, SIG_IGN);
pqsignal(SIGUSR1, procsignal_sigusr1_handler);
pqsignal(SIGUSR2, SIG_IGN);
@@ -260,6 +262,11 @@ WalReceiverMain(const void *startup_data, size_t startup_data_len)
/* Reset some signals that are accepted by postmaster but not here */
pqsignal(SIGCHLD, SIG_DFL);
+ /*
+ * Register timeouts needed
+ */
+ RegisterTimeout(ANYTIME_STATS_UPDATE_TIMEOUT, AnytimeStatsUpdateTimeoutHandler);
+
/* Load the libpq-specific functions */
load_file("libpqwalreceiver", false);
if (WalReceiverFunctions == NULL)
diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c
index 2cde8ebc729..a7214d0dc6f 100644
--- a/src/backend/replication/walsender.c
+++ b/src/backend/replication/walsender.c
@@ -1987,8 +1987,8 @@ WalSndWaitForWal(XLogRecPtr loc)
if (TimestampDifferenceExceeds(last_flush, now,
WALSENDER_STATS_FLUSH_INTERVAL))
{
- pgstat_flush_io(false);
- (void) pgstat_flush_backend(false, PGSTAT_BACKEND_FLUSH_IO);
+ pgstat_flush_io(false, true);
+ (void) pgstat_flush_backend(false, PGSTAT_BACKEND_FLUSH_IO, true);
last_flush = now;
}
@@ -3016,8 +3016,8 @@ WalSndLoop(WalSndSendDataCallback send_data)
if (TimestampDifferenceExceeds(last_flush, now,
WALSENDER_STATS_FLUSH_INTERVAL))
{
- pgstat_flush_io(false);
- (void) pgstat_flush_backend(false, PGSTAT_BACKEND_FLUSH_IO);
+ pgstat_flush_io(false, true);
+ (void) pgstat_flush_backend(false, PGSTAT_BACKEND_FLUSH_IO, true);
last_flush = now;
}
diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c
index 02e9aaa6bca..c7bc409b06f 100644
--- a/src/backend/tcop/postgres.c
+++ b/src/backend/tcop/postgres.c
@@ -3509,6 +3509,18 @@ ProcessInterrupts(void)
pgstat_report_stat(true);
}
+ /*
+ * Flush stats outside of transaction boundary if the timeout fired.
+ * Unlike transactional stats, these can be flushed even inside a running
+ * transaction.
+ */
+ if (AnytimeStatsUpdateTimeoutPending)
+ {
+ AnytimeStatsUpdateTimeoutPending = false;
+
+ pgstat_report_anytime_stat(false);
+ }
+
if (ProcSignalBarrierPending)
ProcessProcSignalBarrier();
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index 11bb71cad5a..411b65aae3e 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -112,6 +112,7 @@
#include "utils/guc_hooks.h"
#include "utils/memutils.h"
#include "utils/pgstat_internal.h"
+#include "utils/timeout.h"
#include "utils/timestamp.h"
@@ -122,8 +123,6 @@
* ----------
*/
-/* minimum interval non-forced stats flushes.*/
-#define PGSTAT_MIN_INTERVAL 1000
/* how long until to block flushing pending stats updates */
#define PGSTAT_MAX_INTERVAL 60000
/* when to call pgstat_report_stat() again, even when idle */
@@ -187,7 +186,8 @@ static void pgstat_init_snapshot_fixed(void);
static void pgstat_reset_after_failure(void);
-static bool pgstat_flush_pending_entries(bool nowait);
+static bool pgstat_flush_pending_entries(bool nowait, bool anytime_only);
+static bool pgstat_flush_fixed_stats(bool nowait, bool anytime_only);
static void pgstat_prep_snapshot(void);
static void pgstat_build_snapshot(void);
@@ -288,6 +288,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = true,
+ .flush_mode = FLUSH_AT_TXN_BOUNDARY,
/* so pg_stat_database entries can be seen in all databases */
.accessed_across_databases = true,
@@ -305,6 +306,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = true,
+ .flush_mode = FLUSH_AT_TXN_BOUNDARY,
.shared_size = sizeof(PgStatShared_Relation),
.shared_data_off = offsetof(PgStatShared_Relation, stats),
@@ -321,6 +323,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = true,
+ .flush_mode = FLUSH_AT_TXN_BOUNDARY,
.shared_size = sizeof(PgStatShared_Function),
.shared_data_off = offsetof(PgStatShared_Function, stats),
@@ -336,6 +339,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = true,
+ .flush_mode = FLUSH_AT_TXN_BOUNDARY,
.accessed_across_databases = true,
@@ -353,6 +357,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = true,
+ .flush_mode = FLUSH_AT_TXN_BOUNDARY,
/* so pg_stat_subscription_stats entries can be seen in all databases */
.accessed_across_databases = true,
@@ -370,6 +375,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = false,
+ .flush_mode = FLUSH_ANYTIME,
.accessed_across_databases = true,
@@ -436,6 +442,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = true,
.write_to_file = true,
+ .flush_mode = FLUSH_ANYTIME,
.snapshot_ctl_off = offsetof(PgStat_Snapshot, io),
.shared_ctl_off = offsetof(PgStat_ShmemControl, io),
@@ -453,6 +460,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = true,
.write_to_file = true,
+ .flush_mode = FLUSH_ANYTIME,
.snapshot_ctl_off = offsetof(PgStat_Snapshot, slru),
.shared_ctl_off = offsetof(PgStat_ShmemControl, slru),
@@ -470,6 +478,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = true,
.write_to_file = true,
+ .flush_mode = FLUSH_ANYTIME,
.snapshot_ctl_off = offsetof(PgStat_Snapshot, wal),
.shared_ctl_off = offsetof(PgStat_ShmemControl, wal),
@@ -775,23 +784,11 @@ pgstat_report_stat(bool force)
partial_flush = false;
/* flush of variable-numbered stats tracked in pending entries list */
- partial_flush |= pgstat_flush_pending_entries(nowait);
+ partial_flush |= pgstat_flush_pending_entries(nowait, false);
/* flush of other stats kinds */
if (pgstat_report_fixed)
- {
- for (PgStat_Kind kind = PGSTAT_KIND_MIN; kind <= PGSTAT_KIND_MAX; kind++)
- {
- const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
-
- if (!kind_info)
- continue;
- if (!kind_info->flush_static_cb)
- continue;
-
- partial_flush |= kind_info->flush_static_cb(nowait);
- }
- }
+ partial_flush |= pgstat_flush_fixed_stats(nowait, false);
last_flush = now;
@@ -1293,7 +1290,8 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
@@ -1345,9 +1343,14 @@ pgstat_delete_pending_entry(PgStat_EntryRef *entry_ref)
/*
* Flush out pending variable-numbered stats.
+ *
+ * If anytime_only is true, only flushes FLUSH_ANYTIME entries.
+ * This is safe to call inside transactions.
+ *
+ * If anytime_only is false, flushes all entries.
*/
static bool
-pgstat_flush_pending_entries(bool nowait)
+pgstat_flush_pending_entries(bool nowait, bool anytime_only)
{
bool have_pending = false;
dlist_node *cur = NULL;
@@ -1377,8 +1380,22 @@ pgstat_flush_pending_entries(bool nowait)
Assert(!kind_info->fixed_amount);
Assert(kind_info->flush_pending_cb != NULL);
+ /* Skip transactional stats if we're in anytime_only mode */
+ if (anytime_only && kind_info->flush_mode == FLUSH_AT_TXN_BOUNDARY)
+ {
+ have_pending = true;
+
+ if (dlist_has_next(&pgStatPending, cur))
+ next = dlist_next_node(&pgStatPending, cur);
+ else
+ next = NULL;
+
+ cur = next;
+ continue;
+ }
+
/* flush the stats, if possible */
- did_flush = kind_info->flush_pending_cb(entry_ref, nowait);
+ did_flush = kind_info->flush_pending_cb(entry_ref, nowait, anytime_only);
Assert(did_flush || nowait);
@@ -1402,6 +1419,33 @@ pgstat_flush_pending_entries(bool nowait)
return have_pending;
}
+/*
+ * Flush fixed-amount stats.
+ *
+ * If anytime_only is true, only flushes FLUSH_ANYTIME stats (safe inside transactions).
+ * If anytime_only is false, flushes all stats with flush_static_cb.
+ */
+static bool
+pgstat_flush_fixed_stats(bool nowait, bool anytime_only)
+{
+ bool partial_flush = false;
+
+ for (PgStat_Kind kind = PGSTAT_KIND_MIN; kind <= PGSTAT_KIND_MAX; kind++)
+ {
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (!kind_info || !kind_info->flush_static_cb)
+ continue;
+
+ /* Skip transactional stats if we're in anytime_only mode */
+ if (anytime_only && kind_info->flush_mode == FLUSH_AT_TXN_BOUNDARY)
+ continue;
+
+ partial_flush |= kind_info->flush_static_cb(nowait, anytime_only);
+ }
+
+ return partial_flush;
+}
/* ------------------------------------------------------------
* Helper / infrastructure functions
@@ -2119,3 +2163,31 @@ assign_stats_fetch_consistency(int newval, void *extra)
if (pgstat_fetch_consistency != newval)
force_stats_snapshot_clear = true;
}
+
+/*
+ * Flushes only FLUSH_ANYTIME stats using non-blocking locks. Transactional
+ * stats (FLUSH_AT_TXN_BOUNDARY) remain pending until transaction boundary.
+ * Safe to call inside transactions.
+ */
+void
+pgstat_report_anytime_stat(bool force)
+{
+ bool nowait = !force;
+
+ pgstat_assert_is_up();
+
+ /* Flush stats outside of transaction boundary */
+ pgstat_flush_pending_entries(nowait, true);
+ pgstat_flush_fixed_stats(nowait, true);
+}
+
+/*
+ * Timeout handler for flushing non-transactional stats.
+ */
+void
+AnytimeStatsUpdateTimeoutHandler(void)
+{
+ AnytimeStatsUpdateTimeoutPending = true;
+ InterruptPending = true;
+ SetLatch(MyLatch);
+}
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index 1350f5f62f1..b0bd220882d 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -31,6 +31,7 @@
#include "storage/procarray.h"
#include "utils/memutils.h"
#include "utils/pgstat_internal.h"
+#include "utils/timeout.h"
/*
* Backend statistics counts waiting to be flushed out. These counters may be
@@ -66,6 +67,9 @@ pgstat_count_backend_io_op_time(IOObject io_object, IOContext io_context,
INSTR_TIME_ADD(PendingBackendStats.pending_io.pending_times[io_object][io_context][io_op],
io_time);
+ /* Schedule next anytime stats update timeout */
+ pgstat_schedule_anytime_update();
+
backend_has_iostats = true;
pgstat_report_fixed = true;
}
@@ -82,6 +86,9 @@ pgstat_count_backend_io_op(IOObject io_object, IOContext io_context,
PendingBackendStats.pending_io.counts[io_object][io_context][io_op] += cnt;
PendingBackendStats.pending_io.bytes[io_object][io_context][io_op] += bytes;
+ /* Schedule next anytime stats update timeout */
+ pgstat_schedule_anytime_update();
+
backend_has_iostats = true;
pgstat_report_fixed = true;
}
@@ -268,7 +275,7 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
* if some statistics could not be flushed due to lock contention.
*/
bool
-pgstat_flush_backend(bool nowait, bits32 flags)
+pgstat_flush_backend(bool nowait, bits32 flags, bool anytime_only)
{
PgStat_EntryRef *entry_ref;
bool has_pending_data = false;
@@ -311,9 +318,9 @@ pgstat_flush_backend(bool nowait, bits32 flags)
* If some stats could not be flushed due to lock contention, return true.
*/
bool
-pgstat_backend_flush_cb(bool nowait)
+pgstat_backend_flush_cb(bool nowait, bool anytime_only)
{
- return pgstat_flush_backend(nowait, PGSTAT_BACKEND_FLUSH_ALL);
+ return pgstat_flush_backend(nowait, PGSTAT_BACKEND_FLUSH_ALL, anytime_only);
}
/*
diff --git a/src/backend/utils/activity/pgstat_bgwriter.c b/src/backend/utils/activity/pgstat_bgwriter.c
index ed2fd801189..1c5f0c3ec40 100644
--- a/src/backend/utils/activity/pgstat_bgwriter.c
+++ b/src/backend/utils/activity/pgstat_bgwriter.c
@@ -61,7 +61,7 @@ pgstat_report_bgwriter(void)
/*
* Report IO statistics
*/
- pgstat_flush_io(false);
+ pgstat_flush_io(false, true);
}
/*
diff --git a/src/backend/utils/activity/pgstat_checkpointer.c b/src/backend/utils/activity/pgstat_checkpointer.c
index 1f70194b7a7..2d89a082464 100644
--- a/src/backend/utils/activity/pgstat_checkpointer.c
+++ b/src/backend/utils/activity/pgstat_checkpointer.c
@@ -68,7 +68,7 @@ pgstat_report_checkpointer(void)
/*
* Report IO statistics
*/
- pgstat_flush_io(false);
+ pgstat_flush_io(false, true);
}
/*
diff --git a/src/backend/utils/activity/pgstat_database.c b/src/backend/utils/activity/pgstat_database.c
index d7f6d4c5ee6..61094f96a6c 100644
--- a/src/backend/utils/activity/pgstat_database.c
+++ b/src/backend/utils/activity/pgstat_database.c
@@ -425,7 +425,7 @@ pgstat_reset_database_timestamp(Oid dboid, TimestampTz ts)
* false without flushing the entry. Otherwise returns true.
*/
bool
-pgstat_database_flush_cb(PgStat_EntryRef *entry_ref, bool nowait)
+pgstat_database_flush_cb(PgStat_EntryRef *entry_ref, bool nowait, bool anytime_only)
{
PgStatShared_Database *sharedent;
PgStat_StatDBEntry *pendingent;
diff --git a/src/backend/utils/activity/pgstat_function.c b/src/backend/utils/activity/pgstat_function.c
index e6b84283c6c..5ba4958382f 100644
--- a/src/backend/utils/activity/pgstat_function.c
+++ b/src/backend/utils/activity/pgstat_function.c
@@ -190,11 +190,13 @@ pgstat_end_function_usage(PgStat_FunctionCallUsage *fcu, bool finalize)
* false without flushing the entry. Otherwise returns true.
*/
bool
-pgstat_function_flush_cb(PgStat_EntryRef *entry_ref, bool nowait)
+pgstat_function_flush_cb(PgStat_EntryRef *entry_ref, bool nowait, bool anytime_only)
{
PgStat_FunctionCounts *localent;
PgStatShared_Function *shfuncent;
+ Assert(!anytime_only);
+
localent = (PgStat_FunctionCounts *) entry_ref->pending;
shfuncent = (PgStatShared_Function *) entry_ref->shared_stats;
diff --git a/src/backend/utils/activity/pgstat_io.c b/src/backend/utils/activity/pgstat_io.c
index 28de24538dc..7cd32900236 100644
--- a/src/backend/utils/activity/pgstat_io.c
+++ b/src/backend/utils/activity/pgstat_io.c
@@ -19,6 +19,7 @@
#include "executor/instrument.h"
#include "storage/bufmgr.h"
#include "utils/pgstat_internal.h"
+#include "utils/timeout.h"
static PgStat_PendingIO PendingIOStats;
static bool have_iostats = false;
@@ -79,6 +80,9 @@ pgstat_count_io_op(IOObject io_object, IOContext io_context, IOOp io_op,
/* Add the per-backend counts */
pgstat_count_backend_io_op(io_object, io_context, io_op, cnt, bytes);
+ /* Schedule next anytime stats update timeout */
+ pgstat_schedule_anytime_update();
+
have_iostats = true;
pgstat_report_fixed = true;
}
@@ -172,9 +176,9 @@ pgstat_fetch_stat_io(void)
* Simpler wrapper of pgstat_io_flush_cb()
*/
void
-pgstat_flush_io(bool nowait)
+pgstat_flush_io(bool nowait, bool anytime_only)
{
- (void) pgstat_io_flush_cb(nowait);
+ (void) pgstat_io_flush_cb(nowait, anytime_only);
}
/*
@@ -186,7 +190,7 @@ pgstat_flush_io(bool nowait)
* acquired. Otherwise, return false.
*/
bool
-pgstat_io_flush_cb(bool nowait)
+pgstat_io_flush_cb(bool nowait, bool anytime_only)
{
LWLock *bktype_lock;
PgStat_BktypeIO *bktype_shstats;
diff --git a/src/backend/utils/activity/pgstat_relation.c b/src/backend/utils/activity/pgstat_relation.c
index bc8c43b96aa..04d21483d93 100644
--- a/src/backend/utils/activity/pgstat_relation.c
+++ b/src/backend/utils/activity/pgstat_relation.c
@@ -267,8 +267,8 @@ pgstat_report_vacuum(Relation rel, PgStat_Counter livetuples,
* is done -- which will likely vacuum many relations -- or until the
* VACUUM command has processed all tables and committed.
*/
- pgstat_flush_io(false);
- (void) pgstat_flush_backend(false, PGSTAT_BACKEND_FLUSH_IO);
+ pgstat_flush_io(false, true);
+ (void) pgstat_flush_backend(false, PGSTAT_BACKEND_FLUSH_IO, true);
}
/*
@@ -362,8 +362,8 @@ pgstat_report_analyze(Relation rel,
pgstat_unlock_entry(entry_ref);
/* see pgstat_report_vacuum() */
- pgstat_flush_io(false);
- (void) pgstat_flush_backend(false, PGSTAT_BACKEND_FLUSH_IO);
+ pgstat_flush_io(false, true);
+ (void) pgstat_flush_backend(false, PGSTAT_BACKEND_FLUSH_IO, true);
}
/*
@@ -812,7 +812,7 @@ pgstat_twophase_postabort(FullTransactionId fxid, uint16 info,
* entry when successfully flushing.
*/
bool
-pgstat_relation_flush_cb(PgStat_EntryRef *entry_ref, bool nowait)
+pgstat_relation_flush_cb(PgStat_EntryRef *entry_ref, bool nowait, bool anytime_only)
{
Oid dboid;
PgStat_TableStatus *lstats; /* pending stats entry */
@@ -820,6 +820,8 @@ pgstat_relation_flush_cb(PgStat_EntryRef *entry_ref, bool nowait)
PgStat_StatTabEntry *tabentry; /* table entry of shared stats */
PgStat_StatDBEntry *dbentry; /* pending database entry */
+ Assert(!anytime_only);
+
dboid = entry_ref->shared_entry->key.dboid;
lstats = (PgStat_TableStatus *) entry_ref->pending;
shtabstats = (PgStatShared_Relation *) entry_ref->shared_stats;
diff --git a/src/backend/utils/activity/pgstat_slru.c b/src/backend/utils/activity/pgstat_slru.c
index 2190f388eae..bf8a4d58673 100644
--- a/src/backend/utils/activity/pgstat_slru.c
+++ b/src/backend/utils/activity/pgstat_slru.c
@@ -19,6 +19,7 @@
#include "utils/pgstat_internal.h"
#include "utils/timestamp.h"
+#include "utils/timeout.h"
static inline PgStat_SLRUStats *get_slru_entry(int slru_idx);
@@ -139,7 +140,7 @@ pgstat_get_slru_index(const char *name)
* acquired. Otherwise return false.
*/
bool
-pgstat_slru_flush_cb(bool nowait)
+pgstat_slru_flush_cb(bool nowait, bool anytime_only)
{
PgStatShared_SLRU *stats_shmem = &pgStatLocal.shmem->slru;
int i;
@@ -223,6 +224,9 @@ get_slru_entry(int slru_idx)
Assert((slru_idx >= 0) && (slru_idx < SLRU_NUM_ELEMENTS));
+ /* Schedule next anytime stats update timeout */
+ pgstat_schedule_anytime_update();
+
have_slrustats = true;
pgstat_report_fixed = true;
diff --git a/src/backend/utils/activity/pgstat_subscription.c b/src/backend/utils/activity/pgstat_subscription.c
index 500b1899188..c4614817966 100644
--- a/src/backend/utils/activity/pgstat_subscription.c
+++ b/src/backend/utils/activity/pgstat_subscription.c
@@ -116,11 +116,13 @@ pgstat_fetch_stat_subscription(Oid subid)
* false without flushing the entry. Otherwise returns true.
*/
bool
-pgstat_subscription_flush_cb(PgStat_EntryRef *entry_ref, bool nowait)
+pgstat_subscription_flush_cb(PgStat_EntryRef *entry_ref, bool nowait, bool anytime_only)
{
PgStat_BackendSubEntry *localent;
PgStatShared_Subscription *shsubent;
+ Assert(!anytime_only);
+
localent = (PgStat_BackendSubEntry *) entry_ref->pending;
shsubent = (PgStatShared_Subscription *) entry_ref->shared_stats;
diff --git a/src/backend/utils/activity/pgstat_wal.c b/src/backend/utils/activity/pgstat_wal.c
index 183e0a7a97b..eb5f8f46925 100644
--- a/src/backend/utils/activity/pgstat_wal.c
+++ b/src/backend/utils/activity/pgstat_wal.c
@@ -51,12 +51,12 @@ pgstat_report_wal(bool force)
nowait = !force;
/* flush wal stats */
- (void) pgstat_wal_flush_cb(nowait);
- pgstat_flush_backend(nowait, PGSTAT_BACKEND_FLUSH_WAL);
+ (void) pgstat_wal_flush_cb(nowait, true);
+ pgstat_flush_backend(nowait, PGSTAT_BACKEND_FLUSH_WAL, true);
/* flush IO stats */
- pgstat_flush_io(nowait);
- (void) pgstat_flush_backend(nowait, PGSTAT_BACKEND_FLUSH_IO);
+ pgstat_flush_io(nowait, true);
+ (void) pgstat_flush_backend(nowait, PGSTAT_BACKEND_FLUSH_IO, true);
}
/*
@@ -88,7 +88,7 @@ pgstat_wal_have_pending(void)
* acquired. Otherwise return false.
*/
bool
-pgstat_wal_flush_cb(bool nowait)
+pgstat_wal_flush_cb(bool nowait, bool anytime_only)
{
PgStatShared_Wal *stats_shmem = &pgStatLocal.shmem->wal;
WalUsage wal_usage_diff = {0};
diff --git a/src/backend/utils/init/globals.c b/src/backend/utils/init/globals.c
index 36ad708b360..ad44826c39e 100644
--- a/src/backend/utils/init/globals.c
+++ b/src/backend/utils/init/globals.c
@@ -40,6 +40,7 @@ volatile sig_atomic_t IdleSessionTimeoutPending = false;
volatile sig_atomic_t ProcSignalBarrierPending = false;
volatile sig_atomic_t LogMemoryContextPending = false;
volatile sig_atomic_t IdleStatsUpdateTimeoutPending = false;
+volatile sig_atomic_t AnytimeStatsUpdateTimeoutPending = false;
volatile uint32 InterruptHoldoffCount = 0;
volatile uint32 QueryCancelHoldoffCount = 0;
volatile uint32 CritSectionCount = 0;
diff --git a/src/backend/utils/init/postinit.c b/src/backend/utils/init/postinit.c
index 3f401faf3de..f45365f47f7 100644
--- a/src/backend/utils/init/postinit.c
+++ b/src/backend/utils/init/postinit.c
@@ -64,6 +64,7 @@
#include "utils/injection_point.h"
#include "utils/memutils.h"
#include "utils/pg_locale.h"
+#include "utils/pgstat_internal.h"
#include "utils/portal.h"
#include "utils/ps_status.h"
#include "utils/snapmgr.h"
@@ -765,6 +766,8 @@ InitPostgres(const char *in_dbname, Oid dboid,
RegisterTimeout(CLIENT_CONNECTION_CHECK_TIMEOUT, ClientCheckTimeoutHandler);
RegisterTimeout(IDLE_STATS_UPDATE_TIMEOUT,
IdleStatsUpdateTimeoutHandler);
+ RegisterTimeout(ANYTIME_STATS_UPDATE_TIMEOUT,
+ AnytimeStatsUpdateTimeoutHandler);
}
/*
diff --git a/src/include/miscadmin.h b/src/include/miscadmin.h
index db559b39c4d..8aeb9628871 100644
--- a/src/include/miscadmin.h
+++ b/src/include/miscadmin.h
@@ -96,6 +96,7 @@ extern PGDLLIMPORT volatile sig_atomic_t IdleSessionTimeoutPending;
extern PGDLLIMPORT volatile sig_atomic_t ProcSignalBarrierPending;
extern PGDLLIMPORT volatile sig_atomic_t LogMemoryContextPending;
extern PGDLLIMPORT volatile sig_atomic_t IdleStatsUpdateTimeoutPending;
+extern PGDLLIMPORT volatile sig_atomic_t AnytimeStatsUpdateTimeoutPending;
extern PGDLLIMPORT volatile sig_atomic_t CheckClientConnectionPending;
extern PGDLLIMPORT volatile sig_atomic_t ClientConnectionLost;
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index fff7ecc2533..b340a680614 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -35,6 +35,9 @@
/* Default directory to store temporary statistics data in */
#define PG_STAT_TMP_DIR "pg_stat_tmp"
+/* Minimum interval non-forced stats flushes */
+#define PGSTAT_MIN_INTERVAL 1000
+
/* Values for track_functions GUC variable --- order is significant! */
typedef enum TrackFunctionsLevel
{
@@ -533,8 +536,21 @@ extern void pgstat_initialize(void);
/* Functions called from backends */
extern long pgstat_report_stat(bool force);
+extern void pgstat_report_anytime_stat(bool force);
extern void pgstat_force_next_flush(void);
+/*
+ * Schedule the next anytime stats update timeout.
+ *
+ * This should be called whenever accumulating statistics that support
+ * FLUSH_ANYTIME flushing mode.
+ */
+#define pgstat_schedule_anytime_update() \
+ do { \
+ if (IsUnderPostmaster && !get_timeout_active(ANYTIME_STATS_UPDATE_TIMEOUT)) \
+ enable_timeout_after(ANYTIME_STATS_UPDATE_TIMEOUT, PGSTAT_MIN_INTERVAL); \
+ } while (0)
+
extern void pgstat_reset_counters(void);
extern void pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid);
extern void pgstat_reset_of_kind(PgStat_Kind kind);
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 9b8fbae00ed..607f4255268 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -224,6 +224,19 @@ typedef struct PgStat_SubXactStatus
PgStat_TableXactStatus *first; /* head of list for this subxact */
} PgStat_SubXactStatus;
+/*
+ * Flush mode for statistics kinds.
+ *
+ * FLUSH_AT_TXN_BOUNDARY has to be the first because we want it to be the
+ * default value.
+ */
+typedef enum PgStat_FlushMode
+{
+ FLUSH_AT_TXN_BOUNDARY, /* All fields can only be flushed at
+ * transaction boundary */
+ FLUSH_ANYTIME, /* All fields can be flushed anytime,
+ * including within transactions */
+} PgStat_FlushMode;
/*
* Metadata for a specific kind of statistics.
@@ -251,6 +264,16 @@ typedef struct PgStat_KindInfo
*/
bool track_entry_count:1;
+ /*
+ * The mode of when to flush stats. See PgStat_FlushMode for more details.
+ *
+ * This member only has meaning for statistics kinds that accumulate
+ * pending stats and use flush callbacks. For kinds that write directly to
+ * shared memory (e.g., archiver, bgwriter, checkpointer), this member has
+ * no effect.
+ */
+ PgStat_FlushMode flush_mode;
+
/*
* The size of an entry in the shared stats hash table (pointed to by
* PgStatShared_HashEntry->body). For fixed-numbered statistics, this is
@@ -297,8 +320,10 @@ typedef struct PgStat_KindInfo
* For variable-numbered stats: flush pending stats. Required if pending
* data is used. See flush_static_cb when dealing with stats data that
* that cannot use PgStat_EntryRef->pending.
+ *
+ * The anytime_only parameter indicates whether this is an anytime flush.
*/
- bool (*flush_pending_cb) (PgStat_EntryRef *sr, bool nowait);
+ bool (*flush_pending_cb) (PgStat_EntryRef *sr, bool nowait, bool anytime_only);
/*
* For variable-numbered stats: delete pending stats. Optional.
@@ -366,8 +391,10 @@ typedef struct PgStat_KindInfo
*
* "pgstat_report_fixed" needs to be set to trigger the flush of pending
* stats.
+ *
+ * The anytime_only parameter indicates whether this is an anytime flush.
*/
- bool (*flush_static_cb) (bool nowait);
+ bool (*flush_static_cb) (bool nowait, bool anytime_only);
/*
* For fixed-numbered statistics: Reset All.
@@ -677,6 +704,7 @@ extern PgStat_EntryRef *pgstat_fetch_pending_entry(PgStat_Kind kind,
extern void *pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid);
extern void pgstat_snapshot_fixed(PgStat_Kind kind);
+extern void AnytimeStatsUpdateTimeoutHandler(void);
/*
@@ -696,8 +724,8 @@ extern void pgstat_archiver_snapshot_cb(void);
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
-extern bool pgstat_flush_backend(bool nowait, bits32 flags);
-extern bool pgstat_backend_flush_cb(bool nowait);
+extern bool pgstat_flush_backend(bool nowait, bits32 flags, bool anytime_only);
+extern bool pgstat_backend_flush_cb(bool nowait, bool anytime_only);
extern void pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header,
TimestampTz ts);
@@ -729,7 +757,7 @@ extern void AtEOXact_PgStat_Database(bool isCommit, bool parallel);
extern PgStat_StatDBEntry *pgstat_prep_database_pending(Oid dboid);
extern void pgstat_reset_database_timestamp(Oid dboid, TimestampTz ts);
-extern bool pgstat_database_flush_cb(PgStat_EntryRef *entry_ref, bool nowait);
+extern bool pgstat_database_flush_cb(PgStat_EntryRef *entry_ref, bool nowait, bool anytime_only);
extern void pgstat_database_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts);
@@ -737,7 +765,7 @@ extern void pgstat_database_reset_timestamp_cb(PgStatShared_Common *header, Time
* Functions in pgstat_function.c
*/
-extern bool pgstat_function_flush_cb(PgStat_EntryRef *entry_ref, bool nowait);
+extern bool pgstat_function_flush_cb(PgStat_EntryRef *entry_ref, bool nowait, bool anytime_only);
extern void pgstat_function_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts);
@@ -745,9 +773,9 @@ extern void pgstat_function_reset_timestamp_cb(PgStatShared_Common *header, Time
* Functions in pgstat_io.c
*/
-extern void pgstat_flush_io(bool nowait);
+extern void pgstat_flush_io(bool nowait, bool anytime_only);
-extern bool pgstat_io_flush_cb(bool nowait);
+extern bool pgstat_io_flush_cb(bool nowait, bool anytime_only);
extern void pgstat_io_init_shmem_cb(void *stats);
extern void pgstat_io_reset_all_cb(TimestampTz ts);
extern void pgstat_io_snapshot_cb(void);
@@ -762,7 +790,7 @@ extern void AtEOSubXact_PgStat_Relations(PgStat_SubXactStatus *xact_state, bool
extern void AtPrepare_PgStat_Relations(PgStat_SubXactStatus *xact_state);
extern void PostPrepare_PgStat_Relations(PgStat_SubXactStatus *xact_state);
-extern bool pgstat_relation_flush_cb(PgStat_EntryRef *entry_ref, bool nowait);
+extern bool pgstat_relation_flush_cb(PgStat_EntryRef *entry_ref, bool nowait, bool anytime_only);
extern void pgstat_relation_delete_pending_cb(PgStat_EntryRef *entry_ref);
extern void pgstat_relation_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts);
@@ -809,7 +837,7 @@ extern PgStatShared_Common *pgstat_init_entry(PgStat_Kind kind,
* Functions in pgstat_slru.c
*/
-extern bool pgstat_slru_flush_cb(bool nowait);
+extern bool pgstat_slru_flush_cb(bool nowait, bool anytime_only);
extern void pgstat_slru_init_shmem_cb(void *stats);
extern void pgstat_slru_reset_all_cb(TimestampTz ts);
extern void pgstat_slru_snapshot_cb(void);
@@ -820,7 +848,7 @@ extern void pgstat_slru_snapshot_cb(void);
*/
extern void pgstat_wal_init_backend_cb(void);
-extern bool pgstat_wal_flush_cb(bool nowait);
+extern bool pgstat_wal_flush_cb(bool nowait, bool anytime_only);
extern void pgstat_wal_init_shmem_cb(void *stats);
extern void pgstat_wal_reset_all_cb(TimestampTz ts);
extern void pgstat_wal_snapshot_cb(void);
@@ -830,7 +858,7 @@ extern void pgstat_wal_snapshot_cb(void);
* Functions in pgstat_subscription.c
*/
-extern bool pgstat_subscription_flush_cb(PgStat_EntryRef *entry_ref, bool nowait);
+extern bool pgstat_subscription_flush_cb(PgStat_EntryRef *entry_ref, bool nowait, bool anytime_only);
extern void pgstat_subscription_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts);
diff --git a/src/include/utils/timeout.h b/src/include/utils/timeout.h
index 0965b590b34..10723bb664c 100644
--- a/src/include/utils/timeout.h
+++ b/src/include/utils/timeout.h
@@ -35,6 +35,7 @@ typedef enum TimeoutId
IDLE_SESSION_TIMEOUT,
IDLE_STATS_UPDATE_TIMEOUT,
CLIENT_CONNECTION_CHECK_TIMEOUT,
+ ANYTIME_STATS_UPDATE_TIMEOUT,
STARTUP_PROGRESS_TIMEOUT,
/* First user-definable timeout reason */
USER_TIMEOUT,
diff --git a/src/test/modules/test_custom_stats/test_custom_var_stats.c b/src/test/modules/test_custom_stats/test_custom_var_stats.c
index 64a8fe63cce..bc0b5d6e0eb 100644
--- a/src/test/modules/test_custom_stats/test_custom_var_stats.c
+++ b/src/test/modules/test_custom_stats/test_custom_var_stats.c
@@ -83,7 +83,7 @@ static dsa_area *custom_stats_description_dsa = NULL;
/* Flush callback: merge pending stats into shared memory */
static bool test_custom_stats_var_flush_pending_cb(PgStat_EntryRef *entry_ref,
- bool nowait);
+ bool nowait, bool anytime_only);
/* Serialization callback: write auxiliary entry data */
static void test_custom_stats_var_to_serialized_data(const PgStat_HashKey *key,
@@ -150,7 +150,7 @@ _PG_init(void)
* Returns false only if nowait=true and lock acquisition fails.
*/
static bool
-test_custom_stats_var_flush_pending_cb(PgStat_EntryRef *entry_ref, bool nowait)
+test_custom_stats_var_flush_pending_cb(PgStat_EntryRef *entry_ref, bool nowait, bool anytime_only)
{
PgStat_StatCustomVarEntry *pending_entry;
PgStatShared_CustomVarEntry *shared_entry;
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 9f5ee8fd482..860f835c088 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -2268,6 +2268,7 @@ PgStat_Counter
PgStat_EntryRef
PgStat_EntryRefHashEntry
PgStat_FetchConsistency
+PgStat_FlushMode
PgStat_FunctionCallUsage
PgStat_FunctionCounts
PgStat_HashKey
--
2.34.1
--DxqFthphbM+ha9Dy
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v6-0002-Add-anytime-flush-tests-for-custom-stats.patch"
^ permalink raw reply [nested|flat] 12+ messages in thread
* [PATCH v7 1/5] Add pgstat_report_anytime_stat() for periodic stats flushing
@ 2026-01-05 09:41 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 12+ messages in thread
From: Bertrand Drouvot @ 2026-01-05 09:41 UTC (permalink / raw)
Long running transactions can accumulate significant statistics (WAL, IO, ...)
that remain unflushed until the transaction ends. This delays visibility of
resource usage in monitoring views like pg_stat_io and pg_stat_wal and produces
spikes when flushed.
This commit introduces pgstat_report_anytime_stat(), which flushes
non transactional statistics even inside active transactions. A new timeout
handler fires every second (if enabled while adding pending stats) to call this
function, ensuring timely stats visibility without waiting for transaction completion.
Implementation details:
- Add PgStat_FlushMode enum to classify stats kinds:
* FLUSH_ANYTIME: Stats that can always be flushed (WAL, IO, ...)
* FLUSH_AT_TXN_BOUNDARY: Stats requiring transaction boundaries
- Modify pgstat_flush_pending_entries() and pgstat_flush_fixed_stats()
to accept a boolean anytime_only parameter:
* When false: flushes all stats (existing behavior)
* When true: flushes only FLUSH_ANYTIME stats and skips FLUSH_AT_TXN_BOUNDARY stats
- The flush_pending_cb and flush_static_cb callbacks now receive an anytime_only
boolean parameter. Most of the time it's not used (except for assertions), but it's
preparatory work for moving the relations stats to anytime (without introducin
a new callback).
- Add pgstat_schedule_anytime_update() macro to schedule the next anytime flush,
relying on PGSTAT_MIN_INTERVAL
The force parameter in pgstat_report_anytime_stat() is currently unused (always
called with force=false) but reserved for future use cases requiring immediate
flushing.
---
src/backend/access/transam/xlog.c | 6 +
src/backend/postmaster/bgwriter.c | 9 +-
src/backend/postmaster/checkpointer.c | 10 +-
src/backend/postmaster/startup.c | 2 +
src/backend/postmaster/walsummarizer.c | 9 +-
src/backend/postmaster/walwriter.c | 9 +-
src/backend/replication/walreceiver.c | 9 +-
src/backend/replication/walsender.c | 8 +-
src/backend/tcop/postgres.c | 12 ++
src/backend/utils/activity/pgstat.c | 112 ++++++++++++++----
src/backend/utils/activity/pgstat_backend.c | 13 +-
src/backend/utils/activity/pgstat_bgwriter.c | 2 +-
.../utils/activity/pgstat_checkpointer.c | 2 +-
src/backend/utils/activity/pgstat_database.c | 2 +-
src/backend/utils/activity/pgstat_function.c | 4 +-
src/backend/utils/activity/pgstat_io.c | 10 +-
src/backend/utils/activity/pgstat_relation.c | 12 +-
src/backend/utils/activity/pgstat_slru.c | 6 +-
.../utils/activity/pgstat_subscription.c | 4 +-
src/backend/utils/activity/pgstat_wal.c | 10 +-
src/backend/utils/init/globals.c | 1 +
src/backend/utils/init/postinit.c | 3 +
src/include/miscadmin.h | 1 +
src/include/pgstat.h | 16 +++
src/include/utils/pgstat_internal.h | 52 ++++++--
src/include/utils/timeout.h | 1 +
.../test_custom_stats/test_custom_var_stats.c | 4 +-
src/tools/pgindent/typedefs.list | 1 +
28 files changed, 264 insertions(+), 66 deletions(-)
10.8% src/backend/postmaster/
6.0% src/backend/replication/
50.7% src/backend/utils/activity/
6.0% src/backend/
19.3% src/include/utils/
5.6% src/include/
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 13ec6225b85..d01b11c7470 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -1085,6 +1085,9 @@ XLogInsertRecord(XLogRecData *rdata,
pgWalUsage.wal_fpi += num_fpi;
pgWalUsage.wal_fpi_bytes += fpi_bytes;
+ /* Schedule next anytime stats update timeout */
+ pgstat_schedule_anytime_update();
+
/* Required for the flush of pending stats WAL data */
pgstat_report_fixed = true;
}
@@ -2066,6 +2069,9 @@ AdvanceXLInsertBuffer(XLogRecPtr upto, TimeLineID tli, bool opportunistic)
pgWalUsage.wal_buffers_full++;
TRACE_POSTGRESQL_WAL_BUFFER_WRITE_DIRTY_DONE();
+ /* Schedule next anytime stats update timeout */
+ pgstat_schedule_anytime_update();
+
/*
* Required for the flush of pending stats WAL data, per
* update of pgWalUsage.
diff --git a/src/backend/postmaster/bgwriter.c b/src/backend/postmaster/bgwriter.c
index 0956bd39a85..059c601c3b8 100644
--- a/src/backend/postmaster/bgwriter.c
+++ b/src/backend/postmaster/bgwriter.c
@@ -49,7 +49,9 @@
#include "storage/smgr.h"
#include "storage/standby.h"
#include "utils/memutils.h"
+#include "utils/pgstat_internal.h"
#include "utils/resowner.h"
+#include "utils/timeout.h"
#include "utils/timestamp.h"
/*
@@ -103,7 +105,7 @@ BackgroundWriterMain(const void *startup_data, size_t startup_data_len)
pqsignal(SIGINT, SIG_IGN);
pqsignal(SIGTERM, SignalHandlerForShutdownRequest);
/* SIGQUIT handler was already set up by InitPostmasterChild */
- pqsignal(SIGALRM, SIG_IGN);
+ InitializeTimeouts(); /* establishes SIGALRM handler */
pqsignal(SIGPIPE, SIG_IGN);
pqsignal(SIGUSR1, procsignal_sigusr1_handler);
pqsignal(SIGUSR2, SIG_IGN);
@@ -113,6 +115,11 @@ BackgroundWriterMain(const void *startup_data, size_t startup_data_len)
*/
pqsignal(SIGCHLD, SIG_DFL);
+ /*
+ * Register timeouts needed
+ */
+ RegisterTimeout(ANYTIME_STATS_UPDATE_TIMEOUT, AnytimeStatsUpdateTimeoutHandler);
+
/*
* We just started, assume there has been either a shutdown or
* end-of-recovery snapshot.
diff --git a/src/backend/postmaster/checkpointer.c b/src/backend/postmaster/checkpointer.c
index e03c19123bc..e11c4b099c8 100644
--- a/src/backend/postmaster/checkpointer.c
+++ b/src/backend/postmaster/checkpointer.c
@@ -66,8 +66,9 @@
#include "utils/acl.h"
#include "utils/guc.h"
#include "utils/memutils.h"
+#include "utils/pgstat_internal.h"
#include "utils/resowner.h"
-
+#include "utils/timeout.h"
/*----------
* Shared memory area for communication between checkpointer and backends
@@ -215,7 +216,7 @@ CheckpointerMain(const void *startup_data, size_t startup_data_len)
pqsignal(SIGINT, ReqShutdownXLOG);
pqsignal(SIGTERM, SIG_IGN); /* ignore SIGTERM */
/* SIGQUIT handler was already set up by InitPostmasterChild */
- pqsignal(SIGALRM, SIG_IGN);
+ InitializeTimeouts(); /* establishes SIGALRM handler */
pqsignal(SIGPIPE, SIG_IGN);
pqsignal(SIGUSR1, procsignal_sigusr1_handler);
pqsignal(SIGUSR2, SignalHandlerForShutdownRequest);
@@ -225,6 +226,11 @@ CheckpointerMain(const void *startup_data, size_t startup_data_len)
*/
pqsignal(SIGCHLD, SIG_DFL);
+ /*
+ * Register timeouts needed
+ */
+ RegisterTimeout(ANYTIME_STATS_UPDATE_TIMEOUT, AnytimeStatsUpdateTimeoutHandler);
+
/*
* Initialize so that first time-driven event happens at the correct time.
*/
diff --git a/src/backend/postmaster/startup.c b/src/backend/postmaster/startup.c
index cdbe53dd262..4954fe425b7 100644
--- a/src/backend/postmaster/startup.c
+++ b/src/backend/postmaster/startup.c
@@ -32,6 +32,7 @@
#include "storage/standby.h"
#include "utils/guc.h"
#include "utils/memutils.h"
+#include "utils/pgstat_internal.h"
#include "utils/timeout.h"
@@ -245,6 +246,7 @@ StartupProcessMain(const void *startup_data, size_t startup_data_len)
RegisterTimeout(STANDBY_DEADLOCK_TIMEOUT, StandbyDeadLockHandler);
RegisterTimeout(STANDBY_TIMEOUT, StandbyTimeoutHandler);
RegisterTimeout(STANDBY_LOCK_TIMEOUT, StandbyLockTimeoutHandler);
+ RegisterTimeout(ANYTIME_STATS_UPDATE_TIMEOUT, AnytimeStatsUpdateTimeoutHandler);
/*
* Unblock signals (they were blocked when the postmaster forked us)
diff --git a/src/backend/postmaster/walsummarizer.c b/src/backend/postmaster/walsummarizer.c
index 2d8f57099fd..9f8ef8159d1 100644
--- a/src/backend/postmaster/walsummarizer.c
+++ b/src/backend/postmaster/walsummarizer.c
@@ -48,6 +48,8 @@
#include "storage/shmem.h"
#include "utils/guc.h"
#include "utils/memutils.h"
+#include "utils/pgstat_internal.h"
+#include "utils/timeout.h"
#include "utils/wait_event.h"
/*
@@ -249,7 +251,7 @@ WalSummarizerMain(const void *startup_data, size_t startup_data_len)
pqsignal(SIGINT, SignalHandlerForShutdownRequest);
pqsignal(SIGTERM, SignalHandlerForShutdownRequest);
/* SIGQUIT handler was already set up by InitPostmasterChild */
- pqsignal(SIGALRM, SIG_IGN);
+ InitializeTimeouts(); /* establishes SIGALRM handler */
pqsignal(SIGPIPE, SIG_IGN);
pqsignal(SIGUSR1, procsignal_sigusr1_handler);
pqsignal(SIGUSR2, SIG_IGN); /* not used */
@@ -271,6 +273,11 @@ WalSummarizerMain(const void *startup_data, size_t startup_data_len)
*/
pqsignal(SIGCHLD, SIG_DFL);
+ /*
+ * Register timeouts needed
+ */
+ RegisterTimeout(ANYTIME_STATS_UPDATE_TIMEOUT, AnytimeStatsUpdateTimeoutHandler);
+
/*
* If an exception is encountered, processing resumes here.
*/
diff --git a/src/backend/postmaster/walwriter.c b/src/backend/postmaster/walwriter.c
index 23e79a32345..ded0f250288 100644
--- a/src/backend/postmaster/walwriter.c
+++ b/src/backend/postmaster/walwriter.c
@@ -61,7 +61,9 @@
#include "storage/smgr.h"
#include "utils/hsearch.h"
#include "utils/memutils.h"
+#include "utils/pgstat_internal.h"
#include "utils/resowner.h"
+#include "utils/timeout.h"
/*
@@ -106,7 +108,7 @@ WalWriterMain(const void *startup_data, size_t startup_data_len)
pqsignal(SIGINT, SignalHandlerForShutdownRequest);
pqsignal(SIGTERM, SignalHandlerForShutdownRequest);
/* SIGQUIT handler was already set up by InitPostmasterChild */
- pqsignal(SIGALRM, SIG_IGN);
+ InitializeTimeouts(); /* establishes SIGALRM handler */
pqsignal(SIGPIPE, SIG_IGN);
pqsignal(SIGUSR1, procsignal_sigusr1_handler);
pqsignal(SIGUSR2, SIG_IGN); /* not used */
@@ -116,6 +118,11 @@ WalWriterMain(const void *startup_data, size_t startup_data_len)
*/
pqsignal(SIGCHLD, SIG_DFL);
+ /*
+ * Register timeouts needed
+ */
+ RegisterTimeout(ANYTIME_STATS_UPDATE_TIMEOUT, AnytimeStatsUpdateTimeoutHandler);
+
/*
* Create a memory context that we will do all our work in. We do this so
* that we can reset the context during error recovery and thereby avoid
diff --git a/src/backend/replication/walreceiver.c b/src/backend/replication/walreceiver.c
index 10e64a7d1f4..11b7c114d3b 100644
--- a/src/backend/replication/walreceiver.c
+++ b/src/backend/replication/walreceiver.c
@@ -77,7 +77,9 @@
#include "utils/builtins.h"
#include "utils/guc.h"
#include "utils/pg_lsn.h"
+#include "utils/pgstat_internal.h"
#include "utils/ps_status.h"
+#include "utils/timeout.h"
#include "utils/timestamp.h"
@@ -252,7 +254,7 @@ WalReceiverMain(const void *startup_data, size_t startup_data_len)
pqsignal(SIGINT, SIG_IGN);
pqsignal(SIGTERM, die); /* request shutdown */
/* SIGQUIT handler was already set up by InitPostmasterChild */
- pqsignal(SIGALRM, SIG_IGN);
+ InitializeTimeouts(); /* establishes SIGALRM handler */
pqsignal(SIGPIPE, SIG_IGN);
pqsignal(SIGUSR1, procsignal_sigusr1_handler);
pqsignal(SIGUSR2, SIG_IGN);
@@ -260,6 +262,11 @@ WalReceiverMain(const void *startup_data, size_t startup_data_len)
/* Reset some signals that are accepted by postmaster but not here */
pqsignal(SIGCHLD, SIG_DFL);
+ /*
+ * Register timeouts needed
+ */
+ RegisterTimeout(ANYTIME_STATS_UPDATE_TIMEOUT, AnytimeStatsUpdateTimeoutHandler);
+
/* Load the libpq-specific functions */
load_file("libpqwalreceiver", false);
if (WalReceiverFunctions == NULL)
diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c
index 2cde8ebc729..a7214d0dc6f 100644
--- a/src/backend/replication/walsender.c
+++ b/src/backend/replication/walsender.c
@@ -1987,8 +1987,8 @@ WalSndWaitForWal(XLogRecPtr loc)
if (TimestampDifferenceExceeds(last_flush, now,
WALSENDER_STATS_FLUSH_INTERVAL))
{
- pgstat_flush_io(false);
- (void) pgstat_flush_backend(false, PGSTAT_BACKEND_FLUSH_IO);
+ pgstat_flush_io(false, true);
+ (void) pgstat_flush_backend(false, PGSTAT_BACKEND_FLUSH_IO, true);
last_flush = now;
}
@@ -3016,8 +3016,8 @@ WalSndLoop(WalSndSendDataCallback send_data)
if (TimestampDifferenceExceeds(last_flush, now,
WALSENDER_STATS_FLUSH_INTERVAL))
{
- pgstat_flush_io(false);
- (void) pgstat_flush_backend(false, PGSTAT_BACKEND_FLUSH_IO);
+ pgstat_flush_io(false, true);
+ (void) pgstat_flush_backend(false, PGSTAT_BACKEND_FLUSH_IO, true);
last_flush = now;
}
diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c
index 21de158adbb..2089de782d5 100644
--- a/src/backend/tcop/postgres.c
+++ b/src/backend/tcop/postgres.c
@@ -3564,6 +3564,18 @@ ProcessInterrupts(void)
pgstat_report_stat(true);
}
+ /*
+ * Flush stats outside of transaction boundary if the timeout fired.
+ * Unlike transactional stats, these can be flushed even inside a running
+ * transaction.
+ */
+ if (AnytimeStatsUpdateTimeoutPending)
+ {
+ AnytimeStatsUpdateTimeoutPending = false;
+
+ pgstat_report_anytime_stat(false);
+ }
+
if (ProcSignalBarrierPending)
ProcessProcSignalBarrier();
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index 11bb71cad5a..a4ff64dc5ce 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -112,6 +112,7 @@
#include "utils/guc_hooks.h"
#include "utils/memutils.h"
#include "utils/pgstat_internal.h"
+#include "utils/timeout.h"
#include "utils/timestamp.h"
@@ -122,8 +123,6 @@
* ----------
*/
-/* minimum interval non-forced stats flushes.*/
-#define PGSTAT_MIN_INTERVAL 1000
/* how long until to block flushing pending stats updates */
#define PGSTAT_MAX_INTERVAL 60000
/* when to call pgstat_report_stat() again, even when idle */
@@ -187,7 +186,8 @@ static void pgstat_init_snapshot_fixed(void);
static void pgstat_reset_after_failure(void);
-static bool pgstat_flush_pending_entries(bool nowait);
+static bool pgstat_flush_pending_entries(bool nowait, bool anytime_only);
+static bool pgstat_flush_fixed_stats(bool nowait, bool anytime_only);
static void pgstat_prep_snapshot(void);
static void pgstat_build_snapshot(void);
@@ -288,6 +288,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = true,
+ .flush_mode = FLUSH_AT_TXN_BOUNDARY,
/* so pg_stat_database entries can be seen in all databases */
.accessed_across_databases = true,
@@ -305,6 +306,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = true,
+ .flush_mode = FLUSH_AT_TXN_BOUNDARY,
.shared_size = sizeof(PgStatShared_Relation),
.shared_data_off = offsetof(PgStatShared_Relation, stats),
@@ -321,6 +323,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = true,
+ .flush_mode = FLUSH_AT_TXN_BOUNDARY,
.shared_size = sizeof(PgStatShared_Function),
.shared_data_off = offsetof(PgStatShared_Function, stats),
@@ -336,6 +339,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = true,
+ .flush_mode = FLUSH_AT_TXN_BOUNDARY,
.accessed_across_databases = true,
@@ -353,6 +357,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = true,
+ .flush_mode = FLUSH_AT_TXN_BOUNDARY,
/* so pg_stat_subscription_stats entries can be seen in all databases */
.accessed_across_databases = true,
@@ -370,6 +375,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = false,
+ .flush_mode = FLUSH_ANYTIME,
.accessed_across_databases = true,
@@ -436,6 +442,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = true,
.write_to_file = true,
+ .flush_mode = FLUSH_ANYTIME,
.snapshot_ctl_off = offsetof(PgStat_Snapshot, io),
.shared_ctl_off = offsetof(PgStat_ShmemControl, io),
@@ -453,6 +460,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = true,
.write_to_file = true,
+ .flush_mode = FLUSH_ANYTIME,
.snapshot_ctl_off = offsetof(PgStat_Snapshot, slru),
.shared_ctl_off = offsetof(PgStat_ShmemControl, slru),
@@ -470,6 +478,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = true,
.write_to_file = true,
+ .flush_mode = FLUSH_ANYTIME,
.snapshot_ctl_off = offsetof(PgStat_Snapshot, wal),
.shared_ctl_off = offsetof(PgStat_ShmemControl, wal),
@@ -775,23 +784,11 @@ pgstat_report_stat(bool force)
partial_flush = false;
/* flush of variable-numbered stats tracked in pending entries list */
- partial_flush |= pgstat_flush_pending_entries(nowait);
+ partial_flush |= pgstat_flush_pending_entries(nowait, false);
/* flush of other stats kinds */
if (pgstat_report_fixed)
- {
- for (PgStat_Kind kind = PGSTAT_KIND_MIN; kind <= PGSTAT_KIND_MAX; kind++)
- {
- const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
-
- if (!kind_info)
- continue;
- if (!kind_info->flush_static_cb)
- continue;
-
- partial_flush |= kind_info->flush_static_cb(nowait);
- }
- }
+ partial_flush |= pgstat_flush_fixed_stats(nowait, false);
last_flush = now;
@@ -1293,7 +1290,8 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
@@ -1345,9 +1343,14 @@ pgstat_delete_pending_entry(PgStat_EntryRef *entry_ref)
/*
* Flush out pending variable-numbered stats.
+ *
+ * If anytime_only is true, only flushes FLUSH_ANYTIME entries.
+ * This is safe to call inside transactions.
+ *
+ * If anytime_only is false, flushes all entries.
*/
static bool
-pgstat_flush_pending_entries(bool nowait)
+pgstat_flush_pending_entries(bool nowait, bool anytime_only)
{
bool have_pending = false;
dlist_node *cur = NULL;
@@ -1377,8 +1380,22 @@ pgstat_flush_pending_entries(bool nowait)
Assert(!kind_info->fixed_amount);
Assert(kind_info->flush_pending_cb != NULL);
+ /* Skip transactional stats if we're in anytime_only mode */
+ if (anytime_only && kind_info->flush_mode == FLUSH_AT_TXN_BOUNDARY)
+ {
+ have_pending = true;
+
+ if (dlist_has_next(&pgStatPending, cur))
+ next = dlist_next_node(&pgStatPending, cur);
+ else
+ next = NULL;
+
+ cur = next;
+ continue;
+ }
+
/* flush the stats, if possible */
- did_flush = kind_info->flush_pending_cb(entry_ref, nowait);
+ did_flush = kind_info->flush_pending_cb(entry_ref, nowait, anytime_only);
Assert(did_flush || nowait);
@@ -1402,6 +1419,33 @@ pgstat_flush_pending_entries(bool nowait)
return have_pending;
}
+/*
+ * Flush fixed-amount stats.
+ *
+ * If anytime_only is true, only flushes FLUSH_ANYTIME stats (safe inside transactions).
+ * If anytime_only is false, flushes all stats with flush_static_cb.
+ */
+static bool
+pgstat_flush_fixed_stats(bool nowait, bool anytime_only)
+{
+ bool partial_flush = false;
+
+ for (PgStat_Kind kind = PGSTAT_KIND_MIN; kind <= PGSTAT_KIND_MAX; kind++)
+ {
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (!kind_info || !kind_info->flush_static_cb)
+ continue;
+
+ /* Skip transactional stats if we're in anytime_only mode */
+ if (anytime_only && kind_info->flush_mode == FLUSH_AT_TXN_BOUNDARY)
+ continue;
+
+ partial_flush |= kind_info->flush_static_cb(nowait, anytime_only);
+ }
+
+ return partial_flush;
+}
/* ------------------------------------------------------------
* Helper / infrastructure functions
@@ -2119,3 +2163,31 @@ assign_stats_fetch_consistency(int newval, void *extra)
if (pgstat_fetch_consistency != newval)
force_stats_snapshot_clear = true;
}
+
+/*
+ * Flushes only FLUSH_ANYTIME stats using non-blocking locks. Transactional
+ * stats (FLUSH_AT_TXN_BOUNDARY) remain pending until transaction boundary.
+ * Safe to call inside transactions.
+ */
+void
+pgstat_report_anytime_stat(bool force)
+{
+ bool nowait = !force;
+
+ pgstat_assert_is_up();
+
+ /* Flush stats outside of transaction boundary */
+ pgstat_flush_pending_entries(nowait, true);
+ pgstat_flush_fixed_stats(nowait, true);
+}
+
+/*
+ * Timeout handler for flushing anytime stats.
+ */
+void
+AnytimeStatsUpdateTimeoutHandler(void)
+{
+ AnytimeStatsUpdateTimeoutPending = true;
+ InterruptPending = true;
+ SetLatch(MyLatch);
+}
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index f2f8d3ff75f..b09316d3ab3 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -31,6 +31,7 @@
#include "storage/procarray.h"
#include "utils/memutils.h"
#include "utils/pgstat_internal.h"
+#include "utils/timeout.h"
/*
* Backend statistics counts waiting to be flushed out. These counters may be
@@ -66,6 +67,9 @@ pgstat_count_backend_io_op_time(IOObject io_object, IOContext io_context,
INSTR_TIME_ADD(PendingBackendStats.pending_io.pending_times[io_object][io_context][io_op],
io_time);
+ /* Schedule next anytime stats update timeout */
+ pgstat_schedule_anytime_update();
+
backend_has_iostats = true;
pgstat_report_fixed = true;
}
@@ -82,6 +86,9 @@ pgstat_count_backend_io_op(IOObject io_object, IOContext io_context,
PendingBackendStats.pending_io.counts[io_object][io_context][io_op] += cnt;
PendingBackendStats.pending_io.bytes[io_object][io_context][io_op] += bytes;
+ /* Schedule next anytime stats update timeout */
+ pgstat_schedule_anytime_update();
+
backend_has_iostats = true;
pgstat_report_fixed = true;
}
@@ -268,7 +275,7 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
* if some statistics could not be flushed due to lock contention.
*/
bool
-pgstat_flush_backend(bool nowait, bits32 flags)
+pgstat_flush_backend(bool nowait, bits32 flags, bool anytime_only)
{
PgStat_EntryRef *entry_ref;
bool has_pending_data = false;
@@ -311,9 +318,9 @@ pgstat_flush_backend(bool nowait, bits32 flags)
* If some stats could not be flushed due to lock contention, return true.
*/
bool
-pgstat_backend_flush_cb(bool nowait)
+pgstat_backend_flush_cb(bool nowait, bool anytime_only)
{
- return pgstat_flush_backend(nowait, PGSTAT_BACKEND_FLUSH_ALL);
+ return pgstat_flush_backend(nowait, PGSTAT_BACKEND_FLUSH_ALL, anytime_only);
}
/*
diff --git a/src/backend/utils/activity/pgstat_bgwriter.c b/src/backend/utils/activity/pgstat_bgwriter.c
index ed2fd801189..1c5f0c3ec40 100644
--- a/src/backend/utils/activity/pgstat_bgwriter.c
+++ b/src/backend/utils/activity/pgstat_bgwriter.c
@@ -61,7 +61,7 @@ pgstat_report_bgwriter(void)
/*
* Report IO statistics
*/
- pgstat_flush_io(false);
+ pgstat_flush_io(false, true);
}
/*
diff --git a/src/backend/utils/activity/pgstat_checkpointer.c b/src/backend/utils/activity/pgstat_checkpointer.c
index 1f70194b7a7..2d89a082464 100644
--- a/src/backend/utils/activity/pgstat_checkpointer.c
+++ b/src/backend/utils/activity/pgstat_checkpointer.c
@@ -68,7 +68,7 @@ pgstat_report_checkpointer(void)
/*
* Report IO statistics
*/
- pgstat_flush_io(false);
+ pgstat_flush_io(false, true);
}
/*
diff --git a/src/backend/utils/activity/pgstat_database.c b/src/backend/utils/activity/pgstat_database.c
index 933dcb5cae5..8e86df60461 100644
--- a/src/backend/utils/activity/pgstat_database.c
+++ b/src/backend/utils/activity/pgstat_database.c
@@ -435,7 +435,7 @@ pgstat_reset_database_timestamp(Oid dboid, TimestampTz ts)
* false without flushing the entry. Otherwise returns true.
*/
bool
-pgstat_database_flush_cb(PgStat_EntryRef *entry_ref, bool nowait)
+pgstat_database_flush_cb(PgStat_EntryRef *entry_ref, bool nowait, bool anytime_only)
{
PgStatShared_Database *sharedent;
PgStat_StatDBEntry *pendingent;
diff --git a/src/backend/utils/activity/pgstat_function.c b/src/backend/utils/activity/pgstat_function.c
index e6b84283c6c..5ba4958382f 100644
--- a/src/backend/utils/activity/pgstat_function.c
+++ b/src/backend/utils/activity/pgstat_function.c
@@ -190,11 +190,13 @@ pgstat_end_function_usage(PgStat_FunctionCallUsage *fcu, bool finalize)
* false without flushing the entry. Otherwise returns true.
*/
bool
-pgstat_function_flush_cb(PgStat_EntryRef *entry_ref, bool nowait)
+pgstat_function_flush_cb(PgStat_EntryRef *entry_ref, bool nowait, bool anytime_only)
{
PgStat_FunctionCounts *localent;
PgStatShared_Function *shfuncent;
+ Assert(!anytime_only);
+
localent = (PgStat_FunctionCounts *) entry_ref->pending;
shfuncent = (PgStatShared_Function *) entry_ref->shared_stats;
diff --git a/src/backend/utils/activity/pgstat_io.c b/src/backend/utils/activity/pgstat_io.c
index 28de24538dc..7cd32900236 100644
--- a/src/backend/utils/activity/pgstat_io.c
+++ b/src/backend/utils/activity/pgstat_io.c
@@ -19,6 +19,7 @@
#include "executor/instrument.h"
#include "storage/bufmgr.h"
#include "utils/pgstat_internal.h"
+#include "utils/timeout.h"
static PgStat_PendingIO PendingIOStats;
static bool have_iostats = false;
@@ -79,6 +80,9 @@ pgstat_count_io_op(IOObject io_object, IOContext io_context, IOOp io_op,
/* Add the per-backend counts */
pgstat_count_backend_io_op(io_object, io_context, io_op, cnt, bytes);
+ /* Schedule next anytime stats update timeout */
+ pgstat_schedule_anytime_update();
+
have_iostats = true;
pgstat_report_fixed = true;
}
@@ -172,9 +176,9 @@ pgstat_fetch_stat_io(void)
* Simpler wrapper of pgstat_io_flush_cb()
*/
void
-pgstat_flush_io(bool nowait)
+pgstat_flush_io(bool nowait, bool anytime_only)
{
- (void) pgstat_io_flush_cb(nowait);
+ (void) pgstat_io_flush_cb(nowait, anytime_only);
}
/*
@@ -186,7 +190,7 @@ pgstat_flush_io(bool nowait)
* acquired. Otherwise, return false.
*/
bool
-pgstat_io_flush_cb(bool nowait)
+pgstat_io_flush_cb(bool nowait, bool anytime_only)
{
LWLock *bktype_lock;
PgStat_BktypeIO *bktype_shstats;
diff --git a/src/backend/utils/activity/pgstat_relation.c b/src/backend/utils/activity/pgstat_relation.c
index bc8c43b96aa..04d21483d93 100644
--- a/src/backend/utils/activity/pgstat_relation.c
+++ b/src/backend/utils/activity/pgstat_relation.c
@@ -267,8 +267,8 @@ pgstat_report_vacuum(Relation rel, PgStat_Counter livetuples,
* is done -- which will likely vacuum many relations -- or until the
* VACUUM command has processed all tables and committed.
*/
- pgstat_flush_io(false);
- (void) pgstat_flush_backend(false, PGSTAT_BACKEND_FLUSH_IO);
+ pgstat_flush_io(false, true);
+ (void) pgstat_flush_backend(false, PGSTAT_BACKEND_FLUSH_IO, true);
}
/*
@@ -362,8 +362,8 @@ pgstat_report_analyze(Relation rel,
pgstat_unlock_entry(entry_ref);
/* see pgstat_report_vacuum() */
- pgstat_flush_io(false);
- (void) pgstat_flush_backend(false, PGSTAT_BACKEND_FLUSH_IO);
+ pgstat_flush_io(false, true);
+ (void) pgstat_flush_backend(false, PGSTAT_BACKEND_FLUSH_IO, true);
}
/*
@@ -812,7 +812,7 @@ pgstat_twophase_postabort(FullTransactionId fxid, uint16 info,
* entry when successfully flushing.
*/
bool
-pgstat_relation_flush_cb(PgStat_EntryRef *entry_ref, bool nowait)
+pgstat_relation_flush_cb(PgStat_EntryRef *entry_ref, bool nowait, bool anytime_only)
{
Oid dboid;
PgStat_TableStatus *lstats; /* pending stats entry */
@@ -820,6 +820,8 @@ pgstat_relation_flush_cb(PgStat_EntryRef *entry_ref, bool nowait)
PgStat_StatTabEntry *tabentry; /* table entry of shared stats */
PgStat_StatDBEntry *dbentry; /* pending database entry */
+ Assert(!anytime_only);
+
dboid = entry_ref->shared_entry->key.dboid;
lstats = (PgStat_TableStatus *) entry_ref->pending;
shtabstats = (PgStatShared_Relation *) entry_ref->shared_stats;
diff --git a/src/backend/utils/activity/pgstat_slru.c b/src/backend/utils/activity/pgstat_slru.c
index 2190f388eae..bf8a4d58673 100644
--- a/src/backend/utils/activity/pgstat_slru.c
+++ b/src/backend/utils/activity/pgstat_slru.c
@@ -19,6 +19,7 @@
#include "utils/pgstat_internal.h"
#include "utils/timestamp.h"
+#include "utils/timeout.h"
static inline PgStat_SLRUStats *get_slru_entry(int slru_idx);
@@ -139,7 +140,7 @@ pgstat_get_slru_index(const char *name)
* acquired. Otherwise return false.
*/
bool
-pgstat_slru_flush_cb(bool nowait)
+pgstat_slru_flush_cb(bool nowait, bool anytime_only)
{
PgStatShared_SLRU *stats_shmem = &pgStatLocal.shmem->slru;
int i;
@@ -223,6 +224,9 @@ get_slru_entry(int slru_idx)
Assert((slru_idx >= 0) && (slru_idx < SLRU_NUM_ELEMENTS));
+ /* Schedule next anytime stats update timeout */
+ pgstat_schedule_anytime_update();
+
have_slrustats = true;
pgstat_report_fixed = true;
diff --git a/src/backend/utils/activity/pgstat_subscription.c b/src/backend/utils/activity/pgstat_subscription.c
index 500b1899188..c4614817966 100644
--- a/src/backend/utils/activity/pgstat_subscription.c
+++ b/src/backend/utils/activity/pgstat_subscription.c
@@ -116,11 +116,13 @@ pgstat_fetch_stat_subscription(Oid subid)
* false without flushing the entry. Otherwise returns true.
*/
bool
-pgstat_subscription_flush_cb(PgStat_EntryRef *entry_ref, bool nowait)
+pgstat_subscription_flush_cb(PgStat_EntryRef *entry_ref, bool nowait, bool anytime_only)
{
PgStat_BackendSubEntry *localent;
PgStatShared_Subscription *shsubent;
+ Assert(!anytime_only);
+
localent = (PgStat_BackendSubEntry *) entry_ref->pending;
shsubent = (PgStatShared_Subscription *) entry_ref->shared_stats;
diff --git a/src/backend/utils/activity/pgstat_wal.c b/src/backend/utils/activity/pgstat_wal.c
index 183e0a7a97b..2c2f3f10e10 100644
--- a/src/backend/utils/activity/pgstat_wal.c
+++ b/src/backend/utils/activity/pgstat_wal.c
@@ -51,12 +51,12 @@ pgstat_report_wal(bool force)
nowait = !force;
/* flush wal stats */
- (void) pgstat_wal_flush_cb(nowait);
- pgstat_flush_backend(nowait, PGSTAT_BACKEND_FLUSH_WAL);
+ (void) pgstat_wal_flush_cb(nowait, true);
+ (void) pgstat_flush_backend(nowait, PGSTAT_BACKEND_FLUSH_WAL, true);
/* flush IO stats */
- pgstat_flush_io(nowait);
- (void) pgstat_flush_backend(nowait, PGSTAT_BACKEND_FLUSH_IO);
+ pgstat_flush_io(nowait, true);
+ (void) pgstat_flush_backend(nowait, PGSTAT_BACKEND_FLUSH_IO, true);
}
/*
@@ -88,7 +88,7 @@ pgstat_wal_have_pending(void)
* acquired. Otherwise return false.
*/
bool
-pgstat_wal_flush_cb(bool nowait)
+pgstat_wal_flush_cb(bool nowait, bool anytime_only)
{
PgStatShared_Wal *stats_shmem = &pgStatLocal.shmem->wal;
WalUsage wal_usage_diff = {0};
diff --git a/src/backend/utils/init/globals.c b/src/backend/utils/init/globals.c
index 36ad708b360..ad44826c39e 100644
--- a/src/backend/utils/init/globals.c
+++ b/src/backend/utils/init/globals.c
@@ -40,6 +40,7 @@ volatile sig_atomic_t IdleSessionTimeoutPending = false;
volatile sig_atomic_t ProcSignalBarrierPending = false;
volatile sig_atomic_t LogMemoryContextPending = false;
volatile sig_atomic_t IdleStatsUpdateTimeoutPending = false;
+volatile sig_atomic_t AnytimeStatsUpdateTimeoutPending = false;
volatile uint32 InterruptHoldoffCount = 0;
volatile uint32 QueryCancelHoldoffCount = 0;
volatile uint32 CritSectionCount = 0;
diff --git a/src/backend/utils/init/postinit.c b/src/backend/utils/init/postinit.c
index b59e08605cc..eeeac1bf39a 100644
--- a/src/backend/utils/init/postinit.c
+++ b/src/backend/utils/init/postinit.c
@@ -64,6 +64,7 @@
#include "utils/injection_point.h"
#include "utils/memutils.h"
#include "utils/pg_locale.h"
+#include "utils/pgstat_internal.h"
#include "utils/portal.h"
#include "utils/ps_status.h"
#include "utils/snapmgr.h"
@@ -773,6 +774,8 @@ InitPostgres(const char *in_dbname, Oid dboid,
RegisterTimeout(CLIENT_CONNECTION_CHECK_TIMEOUT, ClientCheckTimeoutHandler);
RegisterTimeout(IDLE_STATS_UPDATE_TIMEOUT,
IdleStatsUpdateTimeoutHandler);
+ RegisterTimeout(ANYTIME_STATS_UPDATE_TIMEOUT,
+ AnytimeStatsUpdateTimeoutHandler);
}
/*
diff --git a/src/include/miscadmin.h b/src/include/miscadmin.h
index f16f35659b9..84e698da214 100644
--- a/src/include/miscadmin.h
+++ b/src/include/miscadmin.h
@@ -96,6 +96,7 @@ extern PGDLLIMPORT volatile sig_atomic_t IdleSessionTimeoutPending;
extern PGDLLIMPORT volatile sig_atomic_t ProcSignalBarrierPending;
extern PGDLLIMPORT volatile sig_atomic_t LogMemoryContextPending;
extern PGDLLIMPORT volatile sig_atomic_t IdleStatsUpdateTimeoutPending;
+extern PGDLLIMPORT volatile sig_atomic_t AnytimeStatsUpdateTimeoutPending;
extern PGDLLIMPORT volatile sig_atomic_t CheckClientConnectionPending;
extern PGDLLIMPORT volatile sig_atomic_t ClientConnectionLost;
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index fff7ecc2533..b340a680614 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -35,6 +35,9 @@
/* Default directory to store temporary statistics data in */
#define PG_STAT_TMP_DIR "pg_stat_tmp"
+/* Minimum interval non-forced stats flushes */
+#define PGSTAT_MIN_INTERVAL 1000
+
/* Values for track_functions GUC variable --- order is significant! */
typedef enum TrackFunctionsLevel
{
@@ -533,8 +536,21 @@ extern void pgstat_initialize(void);
/* Functions called from backends */
extern long pgstat_report_stat(bool force);
+extern void pgstat_report_anytime_stat(bool force);
extern void pgstat_force_next_flush(void);
+/*
+ * Schedule the next anytime stats update timeout.
+ *
+ * This should be called whenever accumulating statistics that support
+ * FLUSH_ANYTIME flushing mode.
+ */
+#define pgstat_schedule_anytime_update() \
+ do { \
+ if (IsUnderPostmaster && !get_timeout_active(ANYTIME_STATS_UPDATE_TIMEOUT)) \
+ enable_timeout_after(ANYTIME_STATS_UPDATE_TIMEOUT, PGSTAT_MIN_INTERVAL); \
+ } while (0)
+
extern void pgstat_reset_counters(void);
extern void pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid);
extern void pgstat_reset_of_kind(PgStat_Kind kind);
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 9b8fbae00ed..607f4255268 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -224,6 +224,19 @@ typedef struct PgStat_SubXactStatus
PgStat_TableXactStatus *first; /* head of list for this subxact */
} PgStat_SubXactStatus;
+/*
+ * Flush mode for statistics kinds.
+ *
+ * FLUSH_AT_TXN_BOUNDARY has to be the first because we want it to be the
+ * default value.
+ */
+typedef enum PgStat_FlushMode
+{
+ FLUSH_AT_TXN_BOUNDARY, /* All fields can only be flushed at
+ * transaction boundary */
+ FLUSH_ANYTIME, /* All fields can be flushed anytime,
+ * including within transactions */
+} PgStat_FlushMode;
/*
* Metadata for a specific kind of statistics.
@@ -251,6 +264,16 @@ typedef struct PgStat_KindInfo
*/
bool track_entry_count:1;
+ /*
+ * The mode of when to flush stats. See PgStat_FlushMode for more details.
+ *
+ * This member only has meaning for statistics kinds that accumulate
+ * pending stats and use flush callbacks. For kinds that write directly to
+ * shared memory (e.g., archiver, bgwriter, checkpointer), this member has
+ * no effect.
+ */
+ PgStat_FlushMode flush_mode;
+
/*
* The size of an entry in the shared stats hash table (pointed to by
* PgStatShared_HashEntry->body). For fixed-numbered statistics, this is
@@ -297,8 +320,10 @@ typedef struct PgStat_KindInfo
* For variable-numbered stats: flush pending stats. Required if pending
* data is used. See flush_static_cb when dealing with stats data that
* that cannot use PgStat_EntryRef->pending.
+ *
+ * The anytime_only parameter indicates whether this is an anytime flush.
*/
- bool (*flush_pending_cb) (PgStat_EntryRef *sr, bool nowait);
+ bool (*flush_pending_cb) (PgStat_EntryRef *sr, bool nowait, bool anytime_only);
/*
* For variable-numbered stats: delete pending stats. Optional.
@@ -366,8 +391,10 @@ typedef struct PgStat_KindInfo
*
* "pgstat_report_fixed" needs to be set to trigger the flush of pending
* stats.
+ *
+ * The anytime_only parameter indicates whether this is an anytime flush.
*/
- bool (*flush_static_cb) (bool nowait);
+ bool (*flush_static_cb) (bool nowait, bool anytime_only);
/*
* For fixed-numbered statistics: Reset All.
@@ -677,6 +704,7 @@ extern PgStat_EntryRef *pgstat_fetch_pending_entry(PgStat_Kind kind,
extern void *pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid);
extern void pgstat_snapshot_fixed(PgStat_Kind kind);
+extern void AnytimeStatsUpdateTimeoutHandler(void);
/*
@@ -696,8 +724,8 @@ extern void pgstat_archiver_snapshot_cb(void);
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
-extern bool pgstat_flush_backend(bool nowait, bits32 flags);
-extern bool pgstat_backend_flush_cb(bool nowait);
+extern bool pgstat_flush_backend(bool nowait, bits32 flags, bool anytime_only);
+extern bool pgstat_backend_flush_cb(bool nowait, bool anytime_only);
extern void pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header,
TimestampTz ts);
@@ -729,7 +757,7 @@ extern void AtEOXact_PgStat_Database(bool isCommit, bool parallel);
extern PgStat_StatDBEntry *pgstat_prep_database_pending(Oid dboid);
extern void pgstat_reset_database_timestamp(Oid dboid, TimestampTz ts);
-extern bool pgstat_database_flush_cb(PgStat_EntryRef *entry_ref, bool nowait);
+extern bool pgstat_database_flush_cb(PgStat_EntryRef *entry_ref, bool nowait, bool anytime_only);
extern void pgstat_database_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts);
@@ -737,7 +765,7 @@ extern void pgstat_database_reset_timestamp_cb(PgStatShared_Common *header, Time
* Functions in pgstat_function.c
*/
-extern bool pgstat_function_flush_cb(PgStat_EntryRef *entry_ref, bool nowait);
+extern bool pgstat_function_flush_cb(PgStat_EntryRef *entry_ref, bool nowait, bool anytime_only);
extern void pgstat_function_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts);
@@ -745,9 +773,9 @@ extern void pgstat_function_reset_timestamp_cb(PgStatShared_Common *header, Time
* Functions in pgstat_io.c
*/
-extern void pgstat_flush_io(bool nowait);
+extern void pgstat_flush_io(bool nowait, bool anytime_only);
-extern bool pgstat_io_flush_cb(bool nowait);
+extern bool pgstat_io_flush_cb(bool nowait, bool anytime_only);
extern void pgstat_io_init_shmem_cb(void *stats);
extern void pgstat_io_reset_all_cb(TimestampTz ts);
extern void pgstat_io_snapshot_cb(void);
@@ -762,7 +790,7 @@ extern void AtEOSubXact_PgStat_Relations(PgStat_SubXactStatus *xact_state, bool
extern void AtPrepare_PgStat_Relations(PgStat_SubXactStatus *xact_state);
extern void PostPrepare_PgStat_Relations(PgStat_SubXactStatus *xact_state);
-extern bool pgstat_relation_flush_cb(PgStat_EntryRef *entry_ref, bool nowait);
+extern bool pgstat_relation_flush_cb(PgStat_EntryRef *entry_ref, bool nowait, bool anytime_only);
extern void pgstat_relation_delete_pending_cb(PgStat_EntryRef *entry_ref);
extern void pgstat_relation_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts);
@@ -809,7 +837,7 @@ extern PgStatShared_Common *pgstat_init_entry(PgStat_Kind kind,
* Functions in pgstat_slru.c
*/
-extern bool pgstat_slru_flush_cb(bool nowait);
+extern bool pgstat_slru_flush_cb(bool nowait, bool anytime_only);
extern void pgstat_slru_init_shmem_cb(void *stats);
extern void pgstat_slru_reset_all_cb(TimestampTz ts);
extern void pgstat_slru_snapshot_cb(void);
@@ -820,7 +848,7 @@ extern void pgstat_slru_snapshot_cb(void);
*/
extern void pgstat_wal_init_backend_cb(void);
-extern bool pgstat_wal_flush_cb(bool nowait);
+extern bool pgstat_wal_flush_cb(bool nowait, bool anytime_only);
extern void pgstat_wal_init_shmem_cb(void *stats);
extern void pgstat_wal_reset_all_cb(TimestampTz ts);
extern void pgstat_wal_snapshot_cb(void);
@@ -830,7 +858,7 @@ extern void pgstat_wal_snapshot_cb(void);
* Functions in pgstat_subscription.c
*/
-extern bool pgstat_subscription_flush_cb(PgStat_EntryRef *entry_ref, bool nowait);
+extern bool pgstat_subscription_flush_cb(PgStat_EntryRef *entry_ref, bool nowait, bool anytime_only);
extern void pgstat_subscription_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts);
diff --git a/src/include/utils/timeout.h b/src/include/utils/timeout.h
index 0965b590b34..10723bb664c 100644
--- a/src/include/utils/timeout.h
+++ b/src/include/utils/timeout.h
@@ -35,6 +35,7 @@ typedef enum TimeoutId
IDLE_SESSION_TIMEOUT,
IDLE_STATS_UPDATE_TIMEOUT,
CLIENT_CONNECTION_CHECK_TIMEOUT,
+ ANYTIME_STATS_UPDATE_TIMEOUT,
STARTUP_PROGRESS_TIMEOUT,
/* First user-definable timeout reason */
USER_TIMEOUT,
diff --git a/src/test/modules/test_custom_stats/test_custom_var_stats.c b/src/test/modules/test_custom_stats/test_custom_var_stats.c
index 64a8fe63cce..bc0b5d6e0eb 100644
--- a/src/test/modules/test_custom_stats/test_custom_var_stats.c
+++ b/src/test/modules/test_custom_stats/test_custom_var_stats.c
@@ -83,7 +83,7 @@ static dsa_area *custom_stats_description_dsa = NULL;
/* Flush callback: merge pending stats into shared memory */
static bool test_custom_stats_var_flush_pending_cb(PgStat_EntryRef *entry_ref,
- bool nowait);
+ bool nowait, bool anytime_only);
/* Serialization callback: write auxiliary entry data */
static void test_custom_stats_var_to_serialized_data(const PgStat_HashKey *key,
@@ -150,7 +150,7 @@ _PG_init(void)
* Returns false only if nowait=true and lock acquisition fails.
*/
static bool
-test_custom_stats_var_flush_pending_cb(PgStat_EntryRef *entry_ref, bool nowait)
+test_custom_stats_var_flush_pending_cb(PgStat_EntryRef *entry_ref, bool nowait, bool anytime_only)
{
PgStat_StatCustomVarEntry *pending_entry;
PgStatShared_CustomVarEntry *shared_entry;
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 241945734ec..1dbc4b96f51 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -2271,6 +2271,7 @@ PgStat_Counter
PgStat_EntryRef
PgStat_EntryRefHashEntry
PgStat_FetchConsistency
+PgStat_FlushMode
PgStat_FunctionCallUsage
PgStat_FunctionCounts
PgStat_HashKey
--
2.34.1
--C2xzVbxFmVrP7k6O
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v7-0002-Add-anytime-flush-tests-for-custom-stats.patch"
^ permalink raw reply [nested|flat] 12+ messages in thread
* [PATCH v8 1/5] Add pgstat_report_anytime_stat() for periodic stats flushing
@ 2026-01-05 09:41 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 12+ messages in thread
From: Bertrand Drouvot @ 2026-01-05 09:41 UTC (permalink / raw)
Long running transactions can accumulate significant statistics (WAL, IO, ...)
that remain unflushed until the transaction ends. This delays visibility of
resource usage in monitoring views like pg_stat_io and pg_stat_wal and produces
spikes when flushed.
This commit introduces pgstat_report_anytime_stat(), which flushes
non transactional statistics even inside active transactions. A new timeout
handler fires every second (if enabled while adding pending stats) to call this
function, ensuring timely stats visibility without waiting for transaction completion.
Implementation details:
- Add PgStat_FlushMode enum to classify stats kinds:
* FLUSH_ANYTIME: Stats that can always be flushed (WAL, IO, ...)
* FLUSH_AT_TXN_BOUNDARY: Stats requiring transaction boundaries
- Modify pgstat_flush_pending_entries() and pgstat_flush_fixed_stats()
to accept a boolean anytime_only parameter:
* When false: flushes all stats (existing behavior)
* When true: flushes only FLUSH_ANYTIME stats and skips FLUSH_AT_TXN_BOUNDARY stats
- The flush_pending_cb and flush_static_cb callbacks now receive an anytime_only
boolean parameter. Most of the time it's not used (except for assertions), but it's
preparatory work for moving the relations stats to anytime (without introducin
a new callback).
- Add pgstat_schedule_anytime_update() macro to schedule the next anytime flush,
relying on PGSTAT_MIN_INTERVAL
The force parameter in pgstat_report_anytime_stat() is currently unused (always
called with force=false) but reserved for future use cases requiring immediate
flushing.
---
src/backend/access/transam/xlog.c | 6 +
src/backend/postmaster/bgwriter.c | 9 +-
src/backend/postmaster/checkpointer.c | 10 +-
src/backend/postmaster/startup.c | 2 +
src/backend/postmaster/walsummarizer.c | 9 +-
src/backend/postmaster/walwriter.c | 9 +-
src/backend/replication/walreceiver.c | 9 +-
src/backend/replication/walsender.c | 8 +-
src/backend/tcop/postgres.c | 12 ++
src/backend/utils/activity/pgstat.c | 112 ++++++++++++++----
src/backend/utils/activity/pgstat_backend.c | 13 +-
src/backend/utils/activity/pgstat_bgwriter.c | 2 +-
.../utils/activity/pgstat_checkpointer.c | 2 +-
src/backend/utils/activity/pgstat_database.c | 2 +-
src/backend/utils/activity/pgstat_function.c | 4 +-
src/backend/utils/activity/pgstat_io.c | 10 +-
src/backend/utils/activity/pgstat_relation.c | 12 +-
src/backend/utils/activity/pgstat_slru.c | 6 +-
.../utils/activity/pgstat_subscription.c | 4 +-
src/backend/utils/activity/pgstat_wal.c | 10 +-
src/backend/utils/init/globals.c | 1 +
src/backend/utils/init/postinit.c | 3 +
src/include/miscadmin.h | 1 +
src/include/pgstat.h | 16 +++
src/include/utils/pgstat_internal.h | 52 ++++++--
src/include/utils/timeout.h | 1 +
.../test_custom_stats/test_custom_var_stats.c | 4 +-
src/tools/pgindent/typedefs.list | 1 +
28 files changed, 264 insertions(+), 66 deletions(-)
10.8% src/backend/postmaster/
6.0% src/backend/replication/
50.7% src/backend/utils/activity/
6.0% src/backend/
19.3% src/include/utils/
5.6% src/include/
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 13ec6225b85..d01b11c7470 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -1085,6 +1085,9 @@ XLogInsertRecord(XLogRecData *rdata,
pgWalUsage.wal_fpi += num_fpi;
pgWalUsage.wal_fpi_bytes += fpi_bytes;
+ /* Schedule next anytime stats update timeout */
+ pgstat_schedule_anytime_update();
+
/* Required for the flush of pending stats WAL data */
pgstat_report_fixed = true;
}
@@ -2066,6 +2069,9 @@ AdvanceXLInsertBuffer(XLogRecPtr upto, TimeLineID tli, bool opportunistic)
pgWalUsage.wal_buffers_full++;
TRACE_POSTGRESQL_WAL_BUFFER_WRITE_DIRTY_DONE();
+ /* Schedule next anytime stats update timeout */
+ pgstat_schedule_anytime_update();
+
/*
* Required for the flush of pending stats WAL data, per
* update of pgWalUsage.
diff --git a/src/backend/postmaster/bgwriter.c b/src/backend/postmaster/bgwriter.c
index 0956bd39a85..059c601c3b8 100644
--- a/src/backend/postmaster/bgwriter.c
+++ b/src/backend/postmaster/bgwriter.c
@@ -49,7 +49,9 @@
#include "storage/smgr.h"
#include "storage/standby.h"
#include "utils/memutils.h"
+#include "utils/pgstat_internal.h"
#include "utils/resowner.h"
+#include "utils/timeout.h"
#include "utils/timestamp.h"
/*
@@ -103,7 +105,7 @@ BackgroundWriterMain(const void *startup_data, size_t startup_data_len)
pqsignal(SIGINT, SIG_IGN);
pqsignal(SIGTERM, SignalHandlerForShutdownRequest);
/* SIGQUIT handler was already set up by InitPostmasterChild */
- pqsignal(SIGALRM, SIG_IGN);
+ InitializeTimeouts(); /* establishes SIGALRM handler */
pqsignal(SIGPIPE, SIG_IGN);
pqsignal(SIGUSR1, procsignal_sigusr1_handler);
pqsignal(SIGUSR2, SIG_IGN);
@@ -113,6 +115,11 @@ BackgroundWriterMain(const void *startup_data, size_t startup_data_len)
*/
pqsignal(SIGCHLD, SIG_DFL);
+ /*
+ * Register timeouts needed
+ */
+ RegisterTimeout(ANYTIME_STATS_UPDATE_TIMEOUT, AnytimeStatsUpdateTimeoutHandler);
+
/*
* We just started, assume there has been either a shutdown or
* end-of-recovery snapshot.
diff --git a/src/backend/postmaster/checkpointer.c b/src/backend/postmaster/checkpointer.c
index e03c19123bc..e11c4b099c8 100644
--- a/src/backend/postmaster/checkpointer.c
+++ b/src/backend/postmaster/checkpointer.c
@@ -66,8 +66,9 @@
#include "utils/acl.h"
#include "utils/guc.h"
#include "utils/memutils.h"
+#include "utils/pgstat_internal.h"
#include "utils/resowner.h"
-
+#include "utils/timeout.h"
/*----------
* Shared memory area for communication between checkpointer and backends
@@ -215,7 +216,7 @@ CheckpointerMain(const void *startup_data, size_t startup_data_len)
pqsignal(SIGINT, ReqShutdownXLOG);
pqsignal(SIGTERM, SIG_IGN); /* ignore SIGTERM */
/* SIGQUIT handler was already set up by InitPostmasterChild */
- pqsignal(SIGALRM, SIG_IGN);
+ InitializeTimeouts(); /* establishes SIGALRM handler */
pqsignal(SIGPIPE, SIG_IGN);
pqsignal(SIGUSR1, procsignal_sigusr1_handler);
pqsignal(SIGUSR2, SignalHandlerForShutdownRequest);
@@ -225,6 +226,11 @@ CheckpointerMain(const void *startup_data, size_t startup_data_len)
*/
pqsignal(SIGCHLD, SIG_DFL);
+ /*
+ * Register timeouts needed
+ */
+ RegisterTimeout(ANYTIME_STATS_UPDATE_TIMEOUT, AnytimeStatsUpdateTimeoutHandler);
+
/*
* Initialize so that first time-driven event happens at the correct time.
*/
diff --git a/src/backend/postmaster/startup.c b/src/backend/postmaster/startup.c
index cdbe53dd262..4954fe425b7 100644
--- a/src/backend/postmaster/startup.c
+++ b/src/backend/postmaster/startup.c
@@ -32,6 +32,7 @@
#include "storage/standby.h"
#include "utils/guc.h"
#include "utils/memutils.h"
+#include "utils/pgstat_internal.h"
#include "utils/timeout.h"
@@ -245,6 +246,7 @@ StartupProcessMain(const void *startup_data, size_t startup_data_len)
RegisterTimeout(STANDBY_DEADLOCK_TIMEOUT, StandbyDeadLockHandler);
RegisterTimeout(STANDBY_TIMEOUT, StandbyTimeoutHandler);
RegisterTimeout(STANDBY_LOCK_TIMEOUT, StandbyLockTimeoutHandler);
+ RegisterTimeout(ANYTIME_STATS_UPDATE_TIMEOUT, AnytimeStatsUpdateTimeoutHandler);
/*
* Unblock signals (they were blocked when the postmaster forked us)
diff --git a/src/backend/postmaster/walsummarizer.c b/src/backend/postmaster/walsummarizer.c
index 742137edad6..f1bae9d23d6 100644
--- a/src/backend/postmaster/walsummarizer.c
+++ b/src/backend/postmaster/walsummarizer.c
@@ -48,6 +48,8 @@
#include "storage/shmem.h"
#include "utils/guc.h"
#include "utils/memutils.h"
+#include "utils/pgstat_internal.h"
+#include "utils/timeout.h"
#include "utils/wait_event.h"
/*
@@ -246,7 +248,7 @@ WalSummarizerMain(const void *startup_data, size_t startup_data_len)
pqsignal(SIGINT, SIG_IGN); /* no query to cancel */
pqsignal(SIGTERM, SignalHandlerForShutdownRequest);
/* SIGQUIT handler was already set up by InitPostmasterChild */
- pqsignal(SIGALRM, SIG_IGN);
+ InitializeTimeouts(); /* establishes SIGALRM handler */
pqsignal(SIGPIPE, SIG_IGN);
pqsignal(SIGUSR1, procsignal_sigusr1_handler);
pqsignal(SIGUSR2, SIG_IGN); /* not used */
@@ -268,6 +270,11 @@ WalSummarizerMain(const void *startup_data, size_t startup_data_len)
*/
pqsignal(SIGCHLD, SIG_DFL);
+ /*
+ * Register timeouts needed
+ */
+ RegisterTimeout(ANYTIME_STATS_UPDATE_TIMEOUT, AnytimeStatsUpdateTimeoutHandler);
+
/*
* If an exception is encountered, processing resumes here.
*/
diff --git a/src/backend/postmaster/walwriter.c b/src/backend/postmaster/walwriter.c
index 7c0e2809c17..bcf59227a00 100644
--- a/src/backend/postmaster/walwriter.c
+++ b/src/backend/postmaster/walwriter.c
@@ -61,7 +61,9 @@
#include "storage/smgr.h"
#include "utils/hsearch.h"
#include "utils/memutils.h"
+#include "utils/pgstat_internal.h"
#include "utils/resowner.h"
+#include "utils/timeout.h"
/*
@@ -103,7 +105,7 @@ WalWriterMain(const void *startup_data, size_t startup_data_len)
pqsignal(SIGINT, SIG_IGN); /* no query to cancel */
pqsignal(SIGTERM, SignalHandlerForShutdownRequest);
/* SIGQUIT handler was already set up by InitPostmasterChild */
- pqsignal(SIGALRM, SIG_IGN);
+ InitializeTimeouts(); /* establishes SIGALRM handler */
pqsignal(SIGPIPE, SIG_IGN);
pqsignal(SIGUSR1, procsignal_sigusr1_handler);
pqsignal(SIGUSR2, SIG_IGN); /* not used */
@@ -113,6 +115,11 @@ WalWriterMain(const void *startup_data, size_t startup_data_len)
*/
pqsignal(SIGCHLD, SIG_DFL);
+ /*
+ * Register timeouts needed
+ */
+ RegisterTimeout(ANYTIME_STATS_UPDATE_TIMEOUT, AnytimeStatsUpdateTimeoutHandler);
+
/*
* Create a memory context that we will do all our work in. We do this so
* that we can reset the context during error recovery and thereby avoid
diff --git a/src/backend/replication/walreceiver.c b/src/backend/replication/walreceiver.c
index 10e64a7d1f4..11b7c114d3b 100644
--- a/src/backend/replication/walreceiver.c
+++ b/src/backend/replication/walreceiver.c
@@ -77,7 +77,9 @@
#include "utils/builtins.h"
#include "utils/guc.h"
#include "utils/pg_lsn.h"
+#include "utils/pgstat_internal.h"
#include "utils/ps_status.h"
+#include "utils/timeout.h"
#include "utils/timestamp.h"
@@ -252,7 +254,7 @@ WalReceiverMain(const void *startup_data, size_t startup_data_len)
pqsignal(SIGINT, SIG_IGN);
pqsignal(SIGTERM, die); /* request shutdown */
/* SIGQUIT handler was already set up by InitPostmasterChild */
- pqsignal(SIGALRM, SIG_IGN);
+ InitializeTimeouts(); /* establishes SIGALRM handler */
pqsignal(SIGPIPE, SIG_IGN);
pqsignal(SIGUSR1, procsignal_sigusr1_handler);
pqsignal(SIGUSR2, SIG_IGN);
@@ -260,6 +262,11 @@ WalReceiverMain(const void *startup_data, size_t startup_data_len)
/* Reset some signals that are accepted by postmaster but not here */
pqsignal(SIGCHLD, SIG_DFL);
+ /*
+ * Register timeouts needed
+ */
+ RegisterTimeout(ANYTIME_STATS_UPDATE_TIMEOUT, AnytimeStatsUpdateTimeoutHandler);
+
/* Load the libpq-specific functions */
load_file("libpqwalreceiver", false);
if (WalReceiverFunctions == NULL)
diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c
index 2cde8ebc729..a7214d0dc6f 100644
--- a/src/backend/replication/walsender.c
+++ b/src/backend/replication/walsender.c
@@ -1987,8 +1987,8 @@ WalSndWaitForWal(XLogRecPtr loc)
if (TimestampDifferenceExceeds(last_flush, now,
WALSENDER_STATS_FLUSH_INTERVAL))
{
- pgstat_flush_io(false);
- (void) pgstat_flush_backend(false, PGSTAT_BACKEND_FLUSH_IO);
+ pgstat_flush_io(false, true);
+ (void) pgstat_flush_backend(false, PGSTAT_BACKEND_FLUSH_IO, true);
last_flush = now;
}
@@ -3016,8 +3016,8 @@ WalSndLoop(WalSndSendDataCallback send_data)
if (TimestampDifferenceExceeds(last_flush, now,
WALSENDER_STATS_FLUSH_INTERVAL))
{
- pgstat_flush_io(false);
- (void) pgstat_flush_backend(false, PGSTAT_BACKEND_FLUSH_IO);
+ pgstat_flush_io(false, true);
+ (void) pgstat_flush_backend(false, PGSTAT_BACKEND_FLUSH_IO, true);
last_flush = now;
}
diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c
index 21de158adbb..2089de782d5 100644
--- a/src/backend/tcop/postgres.c
+++ b/src/backend/tcop/postgres.c
@@ -3564,6 +3564,18 @@ ProcessInterrupts(void)
pgstat_report_stat(true);
}
+ /*
+ * Flush stats outside of transaction boundary if the timeout fired.
+ * Unlike transactional stats, these can be flushed even inside a running
+ * transaction.
+ */
+ if (AnytimeStatsUpdateTimeoutPending)
+ {
+ AnytimeStatsUpdateTimeoutPending = false;
+
+ pgstat_report_anytime_stat(false);
+ }
+
if (ProcSignalBarrierPending)
ProcessProcSignalBarrier();
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index 11bb71cad5a..a4ff64dc5ce 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -112,6 +112,7 @@
#include "utils/guc_hooks.h"
#include "utils/memutils.h"
#include "utils/pgstat_internal.h"
+#include "utils/timeout.h"
#include "utils/timestamp.h"
@@ -122,8 +123,6 @@
* ----------
*/
-/* minimum interval non-forced stats flushes.*/
-#define PGSTAT_MIN_INTERVAL 1000
/* how long until to block flushing pending stats updates */
#define PGSTAT_MAX_INTERVAL 60000
/* when to call pgstat_report_stat() again, even when idle */
@@ -187,7 +186,8 @@ static void pgstat_init_snapshot_fixed(void);
static void pgstat_reset_after_failure(void);
-static bool pgstat_flush_pending_entries(bool nowait);
+static bool pgstat_flush_pending_entries(bool nowait, bool anytime_only);
+static bool pgstat_flush_fixed_stats(bool nowait, bool anytime_only);
static void pgstat_prep_snapshot(void);
static void pgstat_build_snapshot(void);
@@ -288,6 +288,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = true,
+ .flush_mode = FLUSH_AT_TXN_BOUNDARY,
/* so pg_stat_database entries can be seen in all databases */
.accessed_across_databases = true,
@@ -305,6 +306,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = true,
+ .flush_mode = FLUSH_AT_TXN_BOUNDARY,
.shared_size = sizeof(PgStatShared_Relation),
.shared_data_off = offsetof(PgStatShared_Relation, stats),
@@ -321,6 +323,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = true,
+ .flush_mode = FLUSH_AT_TXN_BOUNDARY,
.shared_size = sizeof(PgStatShared_Function),
.shared_data_off = offsetof(PgStatShared_Function, stats),
@@ -336,6 +339,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = true,
+ .flush_mode = FLUSH_AT_TXN_BOUNDARY,
.accessed_across_databases = true,
@@ -353,6 +357,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = true,
+ .flush_mode = FLUSH_AT_TXN_BOUNDARY,
/* so pg_stat_subscription_stats entries can be seen in all databases */
.accessed_across_databases = true,
@@ -370,6 +375,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = false,
+ .flush_mode = FLUSH_ANYTIME,
.accessed_across_databases = true,
@@ -436,6 +442,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = true,
.write_to_file = true,
+ .flush_mode = FLUSH_ANYTIME,
.snapshot_ctl_off = offsetof(PgStat_Snapshot, io),
.shared_ctl_off = offsetof(PgStat_ShmemControl, io),
@@ -453,6 +460,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = true,
.write_to_file = true,
+ .flush_mode = FLUSH_ANYTIME,
.snapshot_ctl_off = offsetof(PgStat_Snapshot, slru),
.shared_ctl_off = offsetof(PgStat_ShmemControl, slru),
@@ -470,6 +478,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = true,
.write_to_file = true,
+ .flush_mode = FLUSH_ANYTIME,
.snapshot_ctl_off = offsetof(PgStat_Snapshot, wal),
.shared_ctl_off = offsetof(PgStat_ShmemControl, wal),
@@ -775,23 +784,11 @@ pgstat_report_stat(bool force)
partial_flush = false;
/* flush of variable-numbered stats tracked in pending entries list */
- partial_flush |= pgstat_flush_pending_entries(nowait);
+ partial_flush |= pgstat_flush_pending_entries(nowait, false);
/* flush of other stats kinds */
if (pgstat_report_fixed)
- {
- for (PgStat_Kind kind = PGSTAT_KIND_MIN; kind <= PGSTAT_KIND_MAX; kind++)
- {
- const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
-
- if (!kind_info)
- continue;
- if (!kind_info->flush_static_cb)
- continue;
-
- partial_flush |= kind_info->flush_static_cb(nowait);
- }
- }
+ partial_flush |= pgstat_flush_fixed_stats(nowait, false);
last_flush = now;
@@ -1293,7 +1290,8 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
@@ -1345,9 +1343,14 @@ pgstat_delete_pending_entry(PgStat_EntryRef *entry_ref)
/*
* Flush out pending variable-numbered stats.
+ *
+ * If anytime_only is true, only flushes FLUSH_ANYTIME entries.
+ * This is safe to call inside transactions.
+ *
+ * If anytime_only is false, flushes all entries.
*/
static bool
-pgstat_flush_pending_entries(bool nowait)
+pgstat_flush_pending_entries(bool nowait, bool anytime_only)
{
bool have_pending = false;
dlist_node *cur = NULL;
@@ -1377,8 +1380,22 @@ pgstat_flush_pending_entries(bool nowait)
Assert(!kind_info->fixed_amount);
Assert(kind_info->flush_pending_cb != NULL);
+ /* Skip transactional stats if we're in anytime_only mode */
+ if (anytime_only && kind_info->flush_mode == FLUSH_AT_TXN_BOUNDARY)
+ {
+ have_pending = true;
+
+ if (dlist_has_next(&pgStatPending, cur))
+ next = dlist_next_node(&pgStatPending, cur);
+ else
+ next = NULL;
+
+ cur = next;
+ continue;
+ }
+
/* flush the stats, if possible */
- did_flush = kind_info->flush_pending_cb(entry_ref, nowait);
+ did_flush = kind_info->flush_pending_cb(entry_ref, nowait, anytime_only);
Assert(did_flush || nowait);
@@ -1402,6 +1419,33 @@ pgstat_flush_pending_entries(bool nowait)
return have_pending;
}
+/*
+ * Flush fixed-amount stats.
+ *
+ * If anytime_only is true, only flushes FLUSH_ANYTIME stats (safe inside transactions).
+ * If anytime_only is false, flushes all stats with flush_static_cb.
+ */
+static bool
+pgstat_flush_fixed_stats(bool nowait, bool anytime_only)
+{
+ bool partial_flush = false;
+
+ for (PgStat_Kind kind = PGSTAT_KIND_MIN; kind <= PGSTAT_KIND_MAX; kind++)
+ {
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (!kind_info || !kind_info->flush_static_cb)
+ continue;
+
+ /* Skip transactional stats if we're in anytime_only mode */
+ if (anytime_only && kind_info->flush_mode == FLUSH_AT_TXN_BOUNDARY)
+ continue;
+
+ partial_flush |= kind_info->flush_static_cb(nowait, anytime_only);
+ }
+
+ return partial_flush;
+}
/* ------------------------------------------------------------
* Helper / infrastructure functions
@@ -2119,3 +2163,31 @@ assign_stats_fetch_consistency(int newval, void *extra)
if (pgstat_fetch_consistency != newval)
force_stats_snapshot_clear = true;
}
+
+/*
+ * Flushes only FLUSH_ANYTIME stats using non-blocking locks. Transactional
+ * stats (FLUSH_AT_TXN_BOUNDARY) remain pending until transaction boundary.
+ * Safe to call inside transactions.
+ */
+void
+pgstat_report_anytime_stat(bool force)
+{
+ bool nowait = !force;
+
+ pgstat_assert_is_up();
+
+ /* Flush stats outside of transaction boundary */
+ pgstat_flush_pending_entries(nowait, true);
+ pgstat_flush_fixed_stats(nowait, true);
+}
+
+/*
+ * Timeout handler for flushing anytime stats.
+ */
+void
+AnytimeStatsUpdateTimeoutHandler(void)
+{
+ AnytimeStatsUpdateTimeoutPending = true;
+ InterruptPending = true;
+ SetLatch(MyLatch);
+}
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index f2f8d3ff75f..b09316d3ab3 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -31,6 +31,7 @@
#include "storage/procarray.h"
#include "utils/memutils.h"
#include "utils/pgstat_internal.h"
+#include "utils/timeout.h"
/*
* Backend statistics counts waiting to be flushed out. These counters may be
@@ -66,6 +67,9 @@ pgstat_count_backend_io_op_time(IOObject io_object, IOContext io_context,
INSTR_TIME_ADD(PendingBackendStats.pending_io.pending_times[io_object][io_context][io_op],
io_time);
+ /* Schedule next anytime stats update timeout */
+ pgstat_schedule_anytime_update();
+
backend_has_iostats = true;
pgstat_report_fixed = true;
}
@@ -82,6 +86,9 @@ pgstat_count_backend_io_op(IOObject io_object, IOContext io_context,
PendingBackendStats.pending_io.counts[io_object][io_context][io_op] += cnt;
PendingBackendStats.pending_io.bytes[io_object][io_context][io_op] += bytes;
+ /* Schedule next anytime stats update timeout */
+ pgstat_schedule_anytime_update();
+
backend_has_iostats = true;
pgstat_report_fixed = true;
}
@@ -268,7 +275,7 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
* if some statistics could not be flushed due to lock contention.
*/
bool
-pgstat_flush_backend(bool nowait, bits32 flags)
+pgstat_flush_backend(bool nowait, bits32 flags, bool anytime_only)
{
PgStat_EntryRef *entry_ref;
bool has_pending_data = false;
@@ -311,9 +318,9 @@ pgstat_flush_backend(bool nowait, bits32 flags)
* If some stats could not be flushed due to lock contention, return true.
*/
bool
-pgstat_backend_flush_cb(bool nowait)
+pgstat_backend_flush_cb(bool nowait, bool anytime_only)
{
- return pgstat_flush_backend(nowait, PGSTAT_BACKEND_FLUSH_ALL);
+ return pgstat_flush_backend(nowait, PGSTAT_BACKEND_FLUSH_ALL, anytime_only);
}
/*
diff --git a/src/backend/utils/activity/pgstat_bgwriter.c b/src/backend/utils/activity/pgstat_bgwriter.c
index ed2fd801189..1c5f0c3ec40 100644
--- a/src/backend/utils/activity/pgstat_bgwriter.c
+++ b/src/backend/utils/activity/pgstat_bgwriter.c
@@ -61,7 +61,7 @@ pgstat_report_bgwriter(void)
/*
* Report IO statistics
*/
- pgstat_flush_io(false);
+ pgstat_flush_io(false, true);
}
/*
diff --git a/src/backend/utils/activity/pgstat_checkpointer.c b/src/backend/utils/activity/pgstat_checkpointer.c
index 1f70194b7a7..2d89a082464 100644
--- a/src/backend/utils/activity/pgstat_checkpointer.c
+++ b/src/backend/utils/activity/pgstat_checkpointer.c
@@ -68,7 +68,7 @@ pgstat_report_checkpointer(void)
/*
* Report IO statistics
*/
- pgstat_flush_io(false);
+ pgstat_flush_io(false, true);
}
/*
diff --git a/src/backend/utils/activity/pgstat_database.c b/src/backend/utils/activity/pgstat_database.c
index 933dcb5cae5..8e86df60461 100644
--- a/src/backend/utils/activity/pgstat_database.c
+++ b/src/backend/utils/activity/pgstat_database.c
@@ -435,7 +435,7 @@ pgstat_reset_database_timestamp(Oid dboid, TimestampTz ts)
* false without flushing the entry. Otherwise returns true.
*/
bool
-pgstat_database_flush_cb(PgStat_EntryRef *entry_ref, bool nowait)
+pgstat_database_flush_cb(PgStat_EntryRef *entry_ref, bool nowait, bool anytime_only)
{
PgStatShared_Database *sharedent;
PgStat_StatDBEntry *pendingent;
diff --git a/src/backend/utils/activity/pgstat_function.c b/src/backend/utils/activity/pgstat_function.c
index e6b84283c6c..5ba4958382f 100644
--- a/src/backend/utils/activity/pgstat_function.c
+++ b/src/backend/utils/activity/pgstat_function.c
@@ -190,11 +190,13 @@ pgstat_end_function_usage(PgStat_FunctionCallUsage *fcu, bool finalize)
* false without flushing the entry. Otherwise returns true.
*/
bool
-pgstat_function_flush_cb(PgStat_EntryRef *entry_ref, bool nowait)
+pgstat_function_flush_cb(PgStat_EntryRef *entry_ref, bool nowait, bool anytime_only)
{
PgStat_FunctionCounts *localent;
PgStatShared_Function *shfuncent;
+ Assert(!anytime_only);
+
localent = (PgStat_FunctionCounts *) entry_ref->pending;
shfuncent = (PgStatShared_Function *) entry_ref->shared_stats;
diff --git a/src/backend/utils/activity/pgstat_io.c b/src/backend/utils/activity/pgstat_io.c
index 28de24538dc..7cd32900236 100644
--- a/src/backend/utils/activity/pgstat_io.c
+++ b/src/backend/utils/activity/pgstat_io.c
@@ -19,6 +19,7 @@
#include "executor/instrument.h"
#include "storage/bufmgr.h"
#include "utils/pgstat_internal.h"
+#include "utils/timeout.h"
static PgStat_PendingIO PendingIOStats;
static bool have_iostats = false;
@@ -79,6 +80,9 @@ pgstat_count_io_op(IOObject io_object, IOContext io_context, IOOp io_op,
/* Add the per-backend counts */
pgstat_count_backend_io_op(io_object, io_context, io_op, cnt, bytes);
+ /* Schedule next anytime stats update timeout */
+ pgstat_schedule_anytime_update();
+
have_iostats = true;
pgstat_report_fixed = true;
}
@@ -172,9 +176,9 @@ pgstat_fetch_stat_io(void)
* Simpler wrapper of pgstat_io_flush_cb()
*/
void
-pgstat_flush_io(bool nowait)
+pgstat_flush_io(bool nowait, bool anytime_only)
{
- (void) pgstat_io_flush_cb(nowait);
+ (void) pgstat_io_flush_cb(nowait, anytime_only);
}
/*
@@ -186,7 +190,7 @@ pgstat_flush_io(bool nowait)
* acquired. Otherwise, return false.
*/
bool
-pgstat_io_flush_cb(bool nowait)
+pgstat_io_flush_cb(bool nowait, bool anytime_only)
{
LWLock *bktype_lock;
PgStat_BktypeIO *bktype_shstats;
diff --git a/src/backend/utils/activity/pgstat_relation.c b/src/backend/utils/activity/pgstat_relation.c
index bc8c43b96aa..04d21483d93 100644
--- a/src/backend/utils/activity/pgstat_relation.c
+++ b/src/backend/utils/activity/pgstat_relation.c
@@ -267,8 +267,8 @@ pgstat_report_vacuum(Relation rel, PgStat_Counter livetuples,
* is done -- which will likely vacuum many relations -- or until the
* VACUUM command has processed all tables and committed.
*/
- pgstat_flush_io(false);
- (void) pgstat_flush_backend(false, PGSTAT_BACKEND_FLUSH_IO);
+ pgstat_flush_io(false, true);
+ (void) pgstat_flush_backend(false, PGSTAT_BACKEND_FLUSH_IO, true);
}
/*
@@ -362,8 +362,8 @@ pgstat_report_analyze(Relation rel,
pgstat_unlock_entry(entry_ref);
/* see pgstat_report_vacuum() */
- pgstat_flush_io(false);
- (void) pgstat_flush_backend(false, PGSTAT_BACKEND_FLUSH_IO);
+ pgstat_flush_io(false, true);
+ (void) pgstat_flush_backend(false, PGSTAT_BACKEND_FLUSH_IO, true);
}
/*
@@ -812,7 +812,7 @@ pgstat_twophase_postabort(FullTransactionId fxid, uint16 info,
* entry when successfully flushing.
*/
bool
-pgstat_relation_flush_cb(PgStat_EntryRef *entry_ref, bool nowait)
+pgstat_relation_flush_cb(PgStat_EntryRef *entry_ref, bool nowait, bool anytime_only)
{
Oid dboid;
PgStat_TableStatus *lstats; /* pending stats entry */
@@ -820,6 +820,8 @@ pgstat_relation_flush_cb(PgStat_EntryRef *entry_ref, bool nowait)
PgStat_StatTabEntry *tabentry; /* table entry of shared stats */
PgStat_StatDBEntry *dbentry; /* pending database entry */
+ Assert(!anytime_only);
+
dboid = entry_ref->shared_entry->key.dboid;
lstats = (PgStat_TableStatus *) entry_ref->pending;
shtabstats = (PgStatShared_Relation *) entry_ref->shared_stats;
diff --git a/src/backend/utils/activity/pgstat_slru.c b/src/backend/utils/activity/pgstat_slru.c
index 2190f388eae..bf8a4d58673 100644
--- a/src/backend/utils/activity/pgstat_slru.c
+++ b/src/backend/utils/activity/pgstat_slru.c
@@ -19,6 +19,7 @@
#include "utils/pgstat_internal.h"
#include "utils/timestamp.h"
+#include "utils/timeout.h"
static inline PgStat_SLRUStats *get_slru_entry(int slru_idx);
@@ -139,7 +140,7 @@ pgstat_get_slru_index(const char *name)
* acquired. Otherwise return false.
*/
bool
-pgstat_slru_flush_cb(bool nowait)
+pgstat_slru_flush_cb(bool nowait, bool anytime_only)
{
PgStatShared_SLRU *stats_shmem = &pgStatLocal.shmem->slru;
int i;
@@ -223,6 +224,9 @@ get_slru_entry(int slru_idx)
Assert((slru_idx >= 0) && (slru_idx < SLRU_NUM_ELEMENTS));
+ /* Schedule next anytime stats update timeout */
+ pgstat_schedule_anytime_update();
+
have_slrustats = true;
pgstat_report_fixed = true;
diff --git a/src/backend/utils/activity/pgstat_subscription.c b/src/backend/utils/activity/pgstat_subscription.c
index 500b1899188..c4614817966 100644
--- a/src/backend/utils/activity/pgstat_subscription.c
+++ b/src/backend/utils/activity/pgstat_subscription.c
@@ -116,11 +116,13 @@ pgstat_fetch_stat_subscription(Oid subid)
* false without flushing the entry. Otherwise returns true.
*/
bool
-pgstat_subscription_flush_cb(PgStat_EntryRef *entry_ref, bool nowait)
+pgstat_subscription_flush_cb(PgStat_EntryRef *entry_ref, bool nowait, bool anytime_only)
{
PgStat_BackendSubEntry *localent;
PgStatShared_Subscription *shsubent;
+ Assert(!anytime_only);
+
localent = (PgStat_BackendSubEntry *) entry_ref->pending;
shsubent = (PgStatShared_Subscription *) entry_ref->shared_stats;
diff --git a/src/backend/utils/activity/pgstat_wal.c b/src/backend/utils/activity/pgstat_wal.c
index 183e0a7a97b..2c2f3f10e10 100644
--- a/src/backend/utils/activity/pgstat_wal.c
+++ b/src/backend/utils/activity/pgstat_wal.c
@@ -51,12 +51,12 @@ pgstat_report_wal(bool force)
nowait = !force;
/* flush wal stats */
- (void) pgstat_wal_flush_cb(nowait);
- pgstat_flush_backend(nowait, PGSTAT_BACKEND_FLUSH_WAL);
+ (void) pgstat_wal_flush_cb(nowait, true);
+ (void) pgstat_flush_backend(nowait, PGSTAT_BACKEND_FLUSH_WAL, true);
/* flush IO stats */
- pgstat_flush_io(nowait);
- (void) pgstat_flush_backend(nowait, PGSTAT_BACKEND_FLUSH_IO);
+ pgstat_flush_io(nowait, true);
+ (void) pgstat_flush_backend(nowait, PGSTAT_BACKEND_FLUSH_IO, true);
}
/*
@@ -88,7 +88,7 @@ pgstat_wal_have_pending(void)
* acquired. Otherwise return false.
*/
bool
-pgstat_wal_flush_cb(bool nowait)
+pgstat_wal_flush_cb(bool nowait, bool anytime_only)
{
PgStatShared_Wal *stats_shmem = &pgStatLocal.shmem->wal;
WalUsage wal_usage_diff = {0};
diff --git a/src/backend/utils/init/globals.c b/src/backend/utils/init/globals.c
index 36ad708b360..ad44826c39e 100644
--- a/src/backend/utils/init/globals.c
+++ b/src/backend/utils/init/globals.c
@@ -40,6 +40,7 @@ volatile sig_atomic_t IdleSessionTimeoutPending = false;
volatile sig_atomic_t ProcSignalBarrierPending = false;
volatile sig_atomic_t LogMemoryContextPending = false;
volatile sig_atomic_t IdleStatsUpdateTimeoutPending = false;
+volatile sig_atomic_t AnytimeStatsUpdateTimeoutPending = false;
volatile uint32 InterruptHoldoffCount = 0;
volatile uint32 QueryCancelHoldoffCount = 0;
volatile uint32 CritSectionCount = 0;
diff --git a/src/backend/utils/init/postinit.c b/src/backend/utils/init/postinit.c
index b59e08605cc..eeeac1bf39a 100644
--- a/src/backend/utils/init/postinit.c
+++ b/src/backend/utils/init/postinit.c
@@ -64,6 +64,7 @@
#include "utils/injection_point.h"
#include "utils/memutils.h"
#include "utils/pg_locale.h"
+#include "utils/pgstat_internal.h"
#include "utils/portal.h"
#include "utils/ps_status.h"
#include "utils/snapmgr.h"
@@ -773,6 +774,8 @@ InitPostgres(const char *in_dbname, Oid dboid,
RegisterTimeout(CLIENT_CONNECTION_CHECK_TIMEOUT, ClientCheckTimeoutHandler);
RegisterTimeout(IDLE_STATS_UPDATE_TIMEOUT,
IdleStatsUpdateTimeoutHandler);
+ RegisterTimeout(ANYTIME_STATS_UPDATE_TIMEOUT,
+ AnytimeStatsUpdateTimeoutHandler);
}
/*
diff --git a/src/include/miscadmin.h b/src/include/miscadmin.h
index f16f35659b9..84e698da214 100644
--- a/src/include/miscadmin.h
+++ b/src/include/miscadmin.h
@@ -96,6 +96,7 @@ extern PGDLLIMPORT volatile sig_atomic_t IdleSessionTimeoutPending;
extern PGDLLIMPORT volatile sig_atomic_t ProcSignalBarrierPending;
extern PGDLLIMPORT volatile sig_atomic_t LogMemoryContextPending;
extern PGDLLIMPORT volatile sig_atomic_t IdleStatsUpdateTimeoutPending;
+extern PGDLLIMPORT volatile sig_atomic_t AnytimeStatsUpdateTimeoutPending;
extern PGDLLIMPORT volatile sig_atomic_t CheckClientConnectionPending;
extern PGDLLIMPORT volatile sig_atomic_t ClientConnectionLost;
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index fff7ecc2533..b340a680614 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -35,6 +35,9 @@
/* Default directory to store temporary statistics data in */
#define PG_STAT_TMP_DIR "pg_stat_tmp"
+/* Minimum interval non-forced stats flushes */
+#define PGSTAT_MIN_INTERVAL 1000
+
/* Values for track_functions GUC variable --- order is significant! */
typedef enum TrackFunctionsLevel
{
@@ -533,8 +536,21 @@ extern void pgstat_initialize(void);
/* Functions called from backends */
extern long pgstat_report_stat(bool force);
+extern void pgstat_report_anytime_stat(bool force);
extern void pgstat_force_next_flush(void);
+/*
+ * Schedule the next anytime stats update timeout.
+ *
+ * This should be called whenever accumulating statistics that support
+ * FLUSH_ANYTIME flushing mode.
+ */
+#define pgstat_schedule_anytime_update() \
+ do { \
+ if (IsUnderPostmaster && !get_timeout_active(ANYTIME_STATS_UPDATE_TIMEOUT)) \
+ enable_timeout_after(ANYTIME_STATS_UPDATE_TIMEOUT, PGSTAT_MIN_INTERVAL); \
+ } while (0)
+
extern void pgstat_reset_counters(void);
extern void pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid);
extern void pgstat_reset_of_kind(PgStat_Kind kind);
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 9b8fbae00ed..607f4255268 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -224,6 +224,19 @@ typedef struct PgStat_SubXactStatus
PgStat_TableXactStatus *first; /* head of list for this subxact */
} PgStat_SubXactStatus;
+/*
+ * Flush mode for statistics kinds.
+ *
+ * FLUSH_AT_TXN_BOUNDARY has to be the first because we want it to be the
+ * default value.
+ */
+typedef enum PgStat_FlushMode
+{
+ FLUSH_AT_TXN_BOUNDARY, /* All fields can only be flushed at
+ * transaction boundary */
+ FLUSH_ANYTIME, /* All fields can be flushed anytime,
+ * including within transactions */
+} PgStat_FlushMode;
/*
* Metadata for a specific kind of statistics.
@@ -251,6 +264,16 @@ typedef struct PgStat_KindInfo
*/
bool track_entry_count:1;
+ /*
+ * The mode of when to flush stats. See PgStat_FlushMode for more details.
+ *
+ * This member only has meaning for statistics kinds that accumulate
+ * pending stats and use flush callbacks. For kinds that write directly to
+ * shared memory (e.g., archiver, bgwriter, checkpointer), this member has
+ * no effect.
+ */
+ PgStat_FlushMode flush_mode;
+
/*
* The size of an entry in the shared stats hash table (pointed to by
* PgStatShared_HashEntry->body). For fixed-numbered statistics, this is
@@ -297,8 +320,10 @@ typedef struct PgStat_KindInfo
* For variable-numbered stats: flush pending stats. Required if pending
* data is used. See flush_static_cb when dealing with stats data that
* that cannot use PgStat_EntryRef->pending.
+ *
+ * The anytime_only parameter indicates whether this is an anytime flush.
*/
- bool (*flush_pending_cb) (PgStat_EntryRef *sr, bool nowait);
+ bool (*flush_pending_cb) (PgStat_EntryRef *sr, bool nowait, bool anytime_only);
/*
* For variable-numbered stats: delete pending stats. Optional.
@@ -366,8 +391,10 @@ typedef struct PgStat_KindInfo
*
* "pgstat_report_fixed" needs to be set to trigger the flush of pending
* stats.
+ *
+ * The anytime_only parameter indicates whether this is an anytime flush.
*/
- bool (*flush_static_cb) (bool nowait);
+ bool (*flush_static_cb) (bool nowait, bool anytime_only);
/*
* For fixed-numbered statistics: Reset All.
@@ -677,6 +704,7 @@ extern PgStat_EntryRef *pgstat_fetch_pending_entry(PgStat_Kind kind,
extern void *pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid);
extern void pgstat_snapshot_fixed(PgStat_Kind kind);
+extern void AnytimeStatsUpdateTimeoutHandler(void);
/*
@@ -696,8 +724,8 @@ extern void pgstat_archiver_snapshot_cb(void);
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
-extern bool pgstat_flush_backend(bool nowait, bits32 flags);
-extern bool pgstat_backend_flush_cb(bool nowait);
+extern bool pgstat_flush_backend(bool nowait, bits32 flags, bool anytime_only);
+extern bool pgstat_backend_flush_cb(bool nowait, bool anytime_only);
extern void pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header,
TimestampTz ts);
@@ -729,7 +757,7 @@ extern void AtEOXact_PgStat_Database(bool isCommit, bool parallel);
extern PgStat_StatDBEntry *pgstat_prep_database_pending(Oid dboid);
extern void pgstat_reset_database_timestamp(Oid dboid, TimestampTz ts);
-extern bool pgstat_database_flush_cb(PgStat_EntryRef *entry_ref, bool nowait);
+extern bool pgstat_database_flush_cb(PgStat_EntryRef *entry_ref, bool nowait, bool anytime_only);
extern void pgstat_database_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts);
@@ -737,7 +765,7 @@ extern void pgstat_database_reset_timestamp_cb(PgStatShared_Common *header, Time
* Functions in pgstat_function.c
*/
-extern bool pgstat_function_flush_cb(PgStat_EntryRef *entry_ref, bool nowait);
+extern bool pgstat_function_flush_cb(PgStat_EntryRef *entry_ref, bool nowait, bool anytime_only);
extern void pgstat_function_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts);
@@ -745,9 +773,9 @@ extern void pgstat_function_reset_timestamp_cb(PgStatShared_Common *header, Time
* Functions in pgstat_io.c
*/
-extern void pgstat_flush_io(bool nowait);
+extern void pgstat_flush_io(bool nowait, bool anytime_only);
-extern bool pgstat_io_flush_cb(bool nowait);
+extern bool pgstat_io_flush_cb(bool nowait, bool anytime_only);
extern void pgstat_io_init_shmem_cb(void *stats);
extern void pgstat_io_reset_all_cb(TimestampTz ts);
extern void pgstat_io_snapshot_cb(void);
@@ -762,7 +790,7 @@ extern void AtEOSubXact_PgStat_Relations(PgStat_SubXactStatus *xact_state, bool
extern void AtPrepare_PgStat_Relations(PgStat_SubXactStatus *xact_state);
extern void PostPrepare_PgStat_Relations(PgStat_SubXactStatus *xact_state);
-extern bool pgstat_relation_flush_cb(PgStat_EntryRef *entry_ref, bool nowait);
+extern bool pgstat_relation_flush_cb(PgStat_EntryRef *entry_ref, bool nowait, bool anytime_only);
extern void pgstat_relation_delete_pending_cb(PgStat_EntryRef *entry_ref);
extern void pgstat_relation_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts);
@@ -809,7 +837,7 @@ extern PgStatShared_Common *pgstat_init_entry(PgStat_Kind kind,
* Functions in pgstat_slru.c
*/
-extern bool pgstat_slru_flush_cb(bool nowait);
+extern bool pgstat_slru_flush_cb(bool nowait, bool anytime_only);
extern void pgstat_slru_init_shmem_cb(void *stats);
extern void pgstat_slru_reset_all_cb(TimestampTz ts);
extern void pgstat_slru_snapshot_cb(void);
@@ -820,7 +848,7 @@ extern void pgstat_slru_snapshot_cb(void);
*/
extern void pgstat_wal_init_backend_cb(void);
-extern bool pgstat_wal_flush_cb(bool nowait);
+extern bool pgstat_wal_flush_cb(bool nowait, bool anytime_only);
extern void pgstat_wal_init_shmem_cb(void *stats);
extern void pgstat_wal_reset_all_cb(TimestampTz ts);
extern void pgstat_wal_snapshot_cb(void);
@@ -830,7 +858,7 @@ extern void pgstat_wal_snapshot_cb(void);
* Functions in pgstat_subscription.c
*/
-extern bool pgstat_subscription_flush_cb(PgStat_EntryRef *entry_ref, bool nowait);
+extern bool pgstat_subscription_flush_cb(PgStat_EntryRef *entry_ref, bool nowait, bool anytime_only);
extern void pgstat_subscription_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts);
diff --git a/src/include/utils/timeout.h b/src/include/utils/timeout.h
index 0965b590b34..10723bb664c 100644
--- a/src/include/utils/timeout.h
+++ b/src/include/utils/timeout.h
@@ -35,6 +35,7 @@ typedef enum TimeoutId
IDLE_SESSION_TIMEOUT,
IDLE_STATS_UPDATE_TIMEOUT,
CLIENT_CONNECTION_CHECK_TIMEOUT,
+ ANYTIME_STATS_UPDATE_TIMEOUT,
STARTUP_PROGRESS_TIMEOUT,
/* First user-definable timeout reason */
USER_TIMEOUT,
diff --git a/src/test/modules/test_custom_stats/test_custom_var_stats.c b/src/test/modules/test_custom_stats/test_custom_var_stats.c
index 64a8fe63cce..bc0b5d6e0eb 100644
--- a/src/test/modules/test_custom_stats/test_custom_var_stats.c
+++ b/src/test/modules/test_custom_stats/test_custom_var_stats.c
@@ -83,7 +83,7 @@ static dsa_area *custom_stats_description_dsa = NULL;
/* Flush callback: merge pending stats into shared memory */
static bool test_custom_stats_var_flush_pending_cb(PgStat_EntryRef *entry_ref,
- bool nowait);
+ bool nowait, bool anytime_only);
/* Serialization callback: write auxiliary entry data */
static void test_custom_stats_var_to_serialized_data(const PgStat_HashKey *key,
@@ -150,7 +150,7 @@ _PG_init(void)
* Returns false only if nowait=true and lock acquisition fails.
*/
static bool
-test_custom_stats_var_flush_pending_cb(PgStat_EntryRef *entry_ref, bool nowait)
+test_custom_stats_var_flush_pending_cb(PgStat_EntryRef *entry_ref, bool nowait, bool anytime_only)
{
PgStat_StatCustomVarEntry *pending_entry;
PgStatShared_CustomVarEntry *shared_entry;
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 241945734ec..1dbc4b96f51 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -2271,6 +2271,7 @@ PgStat_Counter
PgStat_EntryRef
PgStat_EntryRefHashEntry
PgStat_FetchConsistency
+PgStat_FlushMode
PgStat_FunctionCallUsage
PgStat_FunctionCounts
PgStat_HashKey
--
2.34.1
--OI5irqZsxWxBW9nT
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v8-0002-Add-anytime-flush-tests-for-custom-stats.patch"
^ permalink raw reply [nested|flat] 12+ messages in thread
* [PATCH v9 1/5] Add pgstat_report_anytime_stat() for periodic stats flushing
@ 2026-01-05 09:41 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 12+ messages in thread
From: Bertrand Drouvot @ 2026-01-05 09:41 UTC (permalink / raw)
Long running transactions can accumulate significant statistics (WAL, IO, ...)
that remain unflushed until the transaction ends. This delays visibility of
resource usage in monitoring views like pg_stat_io and pg_stat_wal and produces
spikes when flushed.
This commit introduces pgstat_report_anytime_stat(), which flushes
non transactional statistics even inside active transactions. A new timeout
handler fires every second (if enabled while adding pending stats) to call this
function, ensuring timely stats visibility without waiting for transaction completion.
Implementation details:
- Add PgStat_FlushMode enum to classify stats kinds:
* FLUSH_ANYTIME: Stats that can always be flushed (WAL, IO, ...)
* FLUSH_AT_TXN_BOUNDARY: Stats requiring transaction boundaries
- Modify pgstat_flush_pending_entries() and pgstat_flush_fixed_stats()
to accept a boolean anytime_only parameter:
* When false: flushes all stats (existing behavior)
* When true: flushes only FLUSH_ANYTIME stats and skips FLUSH_AT_TXN_BOUNDARY stats
- The flush_pending_cb and flush_static_cb callbacks now receive an anytime_only
boolean parameter. Most of the time it's not used (except for assertions), but it's
preparatory work for moving the relations stats to anytime (without introducin
a new callback).
- Add pgstat_schedule_anytime_update() macro to schedule the next anytime flush,
relying on PGSTAT_MIN_INTERVAL
The force parameter in pgstat_report_anytime_stat() is currently unused (always
called with force=false) but reserved for future use cases requiring immediate
flushing.
---
src/backend/access/transam/xlog.c | 6 +
src/backend/postmaster/bgwriter.c | 9 +-
src/backend/postmaster/checkpointer.c | 10 +-
src/backend/postmaster/startup.c | 2 +
src/backend/postmaster/walsummarizer.c | 9 +-
src/backend/postmaster/walwriter.c | 9 +-
src/backend/replication/walreceiver.c | 9 +-
src/backend/replication/walsender.c | 8 +-
src/backend/tcop/postgres.c | 12 ++
src/backend/utils/activity/pgstat.c | 120 +++++++++++++++---
src/backend/utils/activity/pgstat_backend.c | 13 +-
src/backend/utils/activity/pgstat_bgwriter.c | 2 +-
.../utils/activity/pgstat_checkpointer.c | 2 +-
src/backend/utils/activity/pgstat_database.c | 2 +-
src/backend/utils/activity/pgstat_function.c | 4 +-
src/backend/utils/activity/pgstat_io.c | 10 +-
src/backend/utils/activity/pgstat_relation.c | 12 +-
src/backend/utils/activity/pgstat_slru.c | 6 +-
.../utils/activity/pgstat_subscription.c | 4 +-
src/backend/utils/activity/pgstat_wal.c | 10 +-
src/backend/utils/init/globals.c | 1 +
src/backend/utils/init/postinit.c | 3 +
src/include/miscadmin.h | 1 +
src/include/pgstat.h | 22 ++++
src/include/utils/pgstat_internal.h | 52 ++++++--
src/include/utils/timeout.h | 1 +
.../test_custom_stats/test_custom_var_stats.c | 4 +-
src/tools/pgindent/typedefs.list | 1 +
28 files changed, 278 insertions(+), 66 deletions(-)
10.5% src/backend/postmaster/
5.8% src/backend/replication/
50.9% src/backend/utils/activity/
5.9% src/backend/
18.8% src/include/utils/
6.6% src/include/
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 13ec6225b85..d01b11c7470 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -1085,6 +1085,9 @@ XLogInsertRecord(XLogRecData *rdata,
pgWalUsage.wal_fpi += num_fpi;
pgWalUsage.wal_fpi_bytes += fpi_bytes;
+ /* Schedule next anytime stats update timeout */
+ pgstat_schedule_anytime_update();
+
/* Required for the flush of pending stats WAL data */
pgstat_report_fixed = true;
}
@@ -2066,6 +2069,9 @@ AdvanceXLInsertBuffer(XLogRecPtr upto, TimeLineID tli, bool opportunistic)
pgWalUsage.wal_buffers_full++;
TRACE_POSTGRESQL_WAL_BUFFER_WRITE_DIRTY_DONE();
+ /* Schedule next anytime stats update timeout */
+ pgstat_schedule_anytime_update();
+
/*
* Required for the flush of pending stats WAL data, per
* update of pgWalUsage.
diff --git a/src/backend/postmaster/bgwriter.c b/src/backend/postmaster/bgwriter.c
index 0956bd39a85..059c601c3b8 100644
--- a/src/backend/postmaster/bgwriter.c
+++ b/src/backend/postmaster/bgwriter.c
@@ -49,7 +49,9 @@
#include "storage/smgr.h"
#include "storage/standby.h"
#include "utils/memutils.h"
+#include "utils/pgstat_internal.h"
#include "utils/resowner.h"
+#include "utils/timeout.h"
#include "utils/timestamp.h"
/*
@@ -103,7 +105,7 @@ BackgroundWriterMain(const void *startup_data, size_t startup_data_len)
pqsignal(SIGINT, SIG_IGN);
pqsignal(SIGTERM, SignalHandlerForShutdownRequest);
/* SIGQUIT handler was already set up by InitPostmasterChild */
- pqsignal(SIGALRM, SIG_IGN);
+ InitializeTimeouts(); /* establishes SIGALRM handler */
pqsignal(SIGPIPE, SIG_IGN);
pqsignal(SIGUSR1, procsignal_sigusr1_handler);
pqsignal(SIGUSR2, SIG_IGN);
@@ -113,6 +115,11 @@ BackgroundWriterMain(const void *startup_data, size_t startup_data_len)
*/
pqsignal(SIGCHLD, SIG_DFL);
+ /*
+ * Register timeouts needed
+ */
+ RegisterTimeout(ANYTIME_STATS_UPDATE_TIMEOUT, AnytimeStatsUpdateTimeoutHandler);
+
/*
* We just started, assume there has been either a shutdown or
* end-of-recovery snapshot.
diff --git a/src/backend/postmaster/checkpointer.c b/src/backend/postmaster/checkpointer.c
index e03c19123bc..e11c4b099c8 100644
--- a/src/backend/postmaster/checkpointer.c
+++ b/src/backend/postmaster/checkpointer.c
@@ -66,8 +66,9 @@
#include "utils/acl.h"
#include "utils/guc.h"
#include "utils/memutils.h"
+#include "utils/pgstat_internal.h"
#include "utils/resowner.h"
-
+#include "utils/timeout.h"
/*----------
* Shared memory area for communication between checkpointer and backends
@@ -215,7 +216,7 @@ CheckpointerMain(const void *startup_data, size_t startup_data_len)
pqsignal(SIGINT, ReqShutdownXLOG);
pqsignal(SIGTERM, SIG_IGN); /* ignore SIGTERM */
/* SIGQUIT handler was already set up by InitPostmasterChild */
- pqsignal(SIGALRM, SIG_IGN);
+ InitializeTimeouts(); /* establishes SIGALRM handler */
pqsignal(SIGPIPE, SIG_IGN);
pqsignal(SIGUSR1, procsignal_sigusr1_handler);
pqsignal(SIGUSR2, SignalHandlerForShutdownRequest);
@@ -225,6 +226,11 @@ CheckpointerMain(const void *startup_data, size_t startup_data_len)
*/
pqsignal(SIGCHLD, SIG_DFL);
+ /*
+ * Register timeouts needed
+ */
+ RegisterTimeout(ANYTIME_STATS_UPDATE_TIMEOUT, AnytimeStatsUpdateTimeoutHandler);
+
/*
* Initialize so that first time-driven event happens at the correct time.
*/
diff --git a/src/backend/postmaster/startup.c b/src/backend/postmaster/startup.c
index cdbe53dd262..4954fe425b7 100644
--- a/src/backend/postmaster/startup.c
+++ b/src/backend/postmaster/startup.c
@@ -32,6 +32,7 @@
#include "storage/standby.h"
#include "utils/guc.h"
#include "utils/memutils.h"
+#include "utils/pgstat_internal.h"
#include "utils/timeout.h"
@@ -245,6 +246,7 @@ StartupProcessMain(const void *startup_data, size_t startup_data_len)
RegisterTimeout(STANDBY_DEADLOCK_TIMEOUT, StandbyDeadLockHandler);
RegisterTimeout(STANDBY_TIMEOUT, StandbyTimeoutHandler);
RegisterTimeout(STANDBY_LOCK_TIMEOUT, StandbyLockTimeoutHandler);
+ RegisterTimeout(ANYTIME_STATS_UPDATE_TIMEOUT, AnytimeStatsUpdateTimeoutHandler);
/*
* Unblock signals (they were blocked when the postmaster forked us)
diff --git a/src/backend/postmaster/walsummarizer.c b/src/backend/postmaster/walsummarizer.c
index 742137edad6..f1bae9d23d6 100644
--- a/src/backend/postmaster/walsummarizer.c
+++ b/src/backend/postmaster/walsummarizer.c
@@ -48,6 +48,8 @@
#include "storage/shmem.h"
#include "utils/guc.h"
#include "utils/memutils.h"
+#include "utils/pgstat_internal.h"
+#include "utils/timeout.h"
#include "utils/wait_event.h"
/*
@@ -246,7 +248,7 @@ WalSummarizerMain(const void *startup_data, size_t startup_data_len)
pqsignal(SIGINT, SIG_IGN); /* no query to cancel */
pqsignal(SIGTERM, SignalHandlerForShutdownRequest);
/* SIGQUIT handler was already set up by InitPostmasterChild */
- pqsignal(SIGALRM, SIG_IGN);
+ InitializeTimeouts(); /* establishes SIGALRM handler */
pqsignal(SIGPIPE, SIG_IGN);
pqsignal(SIGUSR1, procsignal_sigusr1_handler);
pqsignal(SIGUSR2, SIG_IGN); /* not used */
@@ -268,6 +270,11 @@ WalSummarizerMain(const void *startup_data, size_t startup_data_len)
*/
pqsignal(SIGCHLD, SIG_DFL);
+ /*
+ * Register timeouts needed
+ */
+ RegisterTimeout(ANYTIME_STATS_UPDATE_TIMEOUT, AnytimeStatsUpdateTimeoutHandler);
+
/*
* If an exception is encountered, processing resumes here.
*/
diff --git a/src/backend/postmaster/walwriter.c b/src/backend/postmaster/walwriter.c
index 7c0e2809c17..bcf59227a00 100644
--- a/src/backend/postmaster/walwriter.c
+++ b/src/backend/postmaster/walwriter.c
@@ -61,7 +61,9 @@
#include "storage/smgr.h"
#include "utils/hsearch.h"
#include "utils/memutils.h"
+#include "utils/pgstat_internal.h"
#include "utils/resowner.h"
+#include "utils/timeout.h"
/*
@@ -103,7 +105,7 @@ WalWriterMain(const void *startup_data, size_t startup_data_len)
pqsignal(SIGINT, SIG_IGN); /* no query to cancel */
pqsignal(SIGTERM, SignalHandlerForShutdownRequest);
/* SIGQUIT handler was already set up by InitPostmasterChild */
- pqsignal(SIGALRM, SIG_IGN);
+ InitializeTimeouts(); /* establishes SIGALRM handler */
pqsignal(SIGPIPE, SIG_IGN);
pqsignal(SIGUSR1, procsignal_sigusr1_handler);
pqsignal(SIGUSR2, SIG_IGN); /* not used */
@@ -113,6 +115,11 @@ WalWriterMain(const void *startup_data, size_t startup_data_len)
*/
pqsignal(SIGCHLD, SIG_DFL);
+ /*
+ * Register timeouts needed
+ */
+ RegisterTimeout(ANYTIME_STATS_UPDATE_TIMEOUT, AnytimeStatsUpdateTimeoutHandler);
+
/*
* Create a memory context that we will do all our work in. We do this so
* that we can reset the context during error recovery and thereby avoid
diff --git a/src/backend/replication/walreceiver.c b/src/backend/replication/walreceiver.c
index 10e64a7d1f4..11b7c114d3b 100644
--- a/src/backend/replication/walreceiver.c
+++ b/src/backend/replication/walreceiver.c
@@ -77,7 +77,9 @@
#include "utils/builtins.h"
#include "utils/guc.h"
#include "utils/pg_lsn.h"
+#include "utils/pgstat_internal.h"
#include "utils/ps_status.h"
+#include "utils/timeout.h"
#include "utils/timestamp.h"
@@ -252,7 +254,7 @@ WalReceiverMain(const void *startup_data, size_t startup_data_len)
pqsignal(SIGINT, SIG_IGN);
pqsignal(SIGTERM, die); /* request shutdown */
/* SIGQUIT handler was already set up by InitPostmasterChild */
- pqsignal(SIGALRM, SIG_IGN);
+ InitializeTimeouts(); /* establishes SIGALRM handler */
pqsignal(SIGPIPE, SIG_IGN);
pqsignal(SIGUSR1, procsignal_sigusr1_handler);
pqsignal(SIGUSR2, SIG_IGN);
@@ -260,6 +262,11 @@ WalReceiverMain(const void *startup_data, size_t startup_data_len)
/* Reset some signals that are accepted by postmaster but not here */
pqsignal(SIGCHLD, SIG_DFL);
+ /*
+ * Register timeouts needed
+ */
+ RegisterTimeout(ANYTIME_STATS_UPDATE_TIMEOUT, AnytimeStatsUpdateTimeoutHandler);
+
/* Load the libpq-specific functions */
load_file("libpqwalreceiver", false);
if (WalReceiverFunctions == NULL)
diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c
index 2cde8ebc729..a7214d0dc6f 100644
--- a/src/backend/replication/walsender.c
+++ b/src/backend/replication/walsender.c
@@ -1987,8 +1987,8 @@ WalSndWaitForWal(XLogRecPtr loc)
if (TimestampDifferenceExceeds(last_flush, now,
WALSENDER_STATS_FLUSH_INTERVAL))
{
- pgstat_flush_io(false);
- (void) pgstat_flush_backend(false, PGSTAT_BACKEND_FLUSH_IO);
+ pgstat_flush_io(false, true);
+ (void) pgstat_flush_backend(false, PGSTAT_BACKEND_FLUSH_IO, true);
last_flush = now;
}
@@ -3016,8 +3016,8 @@ WalSndLoop(WalSndSendDataCallback send_data)
if (TimestampDifferenceExceeds(last_flush, now,
WALSENDER_STATS_FLUSH_INTERVAL))
{
- pgstat_flush_io(false);
- (void) pgstat_flush_backend(false, PGSTAT_BACKEND_FLUSH_IO);
+ pgstat_flush_io(false, true);
+ (void) pgstat_flush_backend(false, PGSTAT_BACKEND_FLUSH_IO, true);
last_flush = now;
}
diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c
index 21de158adbb..2089de782d5 100644
--- a/src/backend/tcop/postgres.c
+++ b/src/backend/tcop/postgres.c
@@ -3564,6 +3564,18 @@ ProcessInterrupts(void)
pgstat_report_stat(true);
}
+ /*
+ * Flush stats outside of transaction boundary if the timeout fired.
+ * Unlike transactional stats, these can be flushed even inside a running
+ * transaction.
+ */
+ if (AnytimeStatsUpdateTimeoutPending)
+ {
+ AnytimeStatsUpdateTimeoutPending = false;
+
+ pgstat_report_anytime_stat(false);
+ }
+
if (ProcSignalBarrierPending)
ProcessProcSignalBarrier();
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index 11bb71cad5a..419dc512d9b 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -112,6 +112,7 @@
#include "utils/guc_hooks.h"
#include "utils/memutils.h"
#include "utils/pgstat_internal.h"
+#include "utils/timeout.h"
#include "utils/timestamp.h"
@@ -122,8 +123,6 @@
* ----------
*/
-/* minimum interval non-forced stats flushes.*/
-#define PGSTAT_MIN_INTERVAL 1000
/* how long until to block flushing pending stats updates */
#define PGSTAT_MAX_INTERVAL 60000
/* when to call pgstat_report_stat() again, even when idle */
@@ -187,7 +186,8 @@ static void pgstat_init_snapshot_fixed(void);
static void pgstat_reset_after_failure(void);
-static bool pgstat_flush_pending_entries(bool nowait);
+static bool pgstat_flush_pending_entries(bool nowait, bool anytime_only);
+static bool pgstat_flush_fixed_stats(bool nowait, bool anytime_only);
static void pgstat_prep_snapshot(void);
static void pgstat_build_snapshot(void);
@@ -218,6 +218,12 @@ PgStat_LocalState pgStatLocal;
*/
bool pgstat_report_fixed = false;
+/*
+ * Track when there is pending anytime flush to avoid relying on
+ * get_timeout_active() in hot pathes.
+ */
+bool pgstat_pending_anytime = false;
+
/* ----------
* Local data
*
@@ -288,6 +294,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = true,
+ .flush_mode = FLUSH_AT_TXN_BOUNDARY,
/* so pg_stat_database entries can be seen in all databases */
.accessed_across_databases = true,
@@ -305,6 +312,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = true,
+ .flush_mode = FLUSH_AT_TXN_BOUNDARY,
.shared_size = sizeof(PgStatShared_Relation),
.shared_data_off = offsetof(PgStatShared_Relation, stats),
@@ -321,6 +329,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = true,
+ .flush_mode = FLUSH_AT_TXN_BOUNDARY,
.shared_size = sizeof(PgStatShared_Function),
.shared_data_off = offsetof(PgStatShared_Function, stats),
@@ -336,6 +345,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = true,
+ .flush_mode = FLUSH_AT_TXN_BOUNDARY,
.accessed_across_databases = true,
@@ -353,6 +363,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = true,
+ .flush_mode = FLUSH_AT_TXN_BOUNDARY,
/* so pg_stat_subscription_stats entries can be seen in all databases */
.accessed_across_databases = true,
@@ -370,6 +381,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = false,
+ .flush_mode = FLUSH_ANYTIME,
.accessed_across_databases = true,
@@ -436,6 +448,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = true,
.write_to_file = true,
+ .flush_mode = FLUSH_ANYTIME,
.snapshot_ctl_off = offsetof(PgStat_Snapshot, io),
.shared_ctl_off = offsetof(PgStat_ShmemControl, io),
@@ -453,6 +466,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = true,
.write_to_file = true,
+ .flush_mode = FLUSH_ANYTIME,
.snapshot_ctl_off = offsetof(PgStat_Snapshot, slru),
.shared_ctl_off = offsetof(PgStat_ShmemControl, slru),
@@ -470,6 +484,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = true,
.write_to_file = true,
+ .flush_mode = FLUSH_ANYTIME,
.snapshot_ctl_off = offsetof(PgStat_Snapshot, wal),
.shared_ctl_off = offsetof(PgStat_ShmemControl, wal),
@@ -775,23 +790,11 @@ pgstat_report_stat(bool force)
partial_flush = false;
/* flush of variable-numbered stats tracked in pending entries list */
- partial_flush |= pgstat_flush_pending_entries(nowait);
+ partial_flush |= pgstat_flush_pending_entries(nowait, false);
/* flush of other stats kinds */
if (pgstat_report_fixed)
- {
- for (PgStat_Kind kind = PGSTAT_KIND_MIN; kind <= PGSTAT_KIND_MAX; kind++)
- {
- const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
-
- if (!kind_info)
- continue;
- if (!kind_info->flush_static_cb)
- continue;
-
- partial_flush |= kind_info->flush_static_cb(nowait);
- }
- }
+ partial_flush |= pgstat_flush_fixed_stats(nowait, false);
last_flush = now;
@@ -1293,7 +1296,8 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
@@ -1345,9 +1349,14 @@ pgstat_delete_pending_entry(PgStat_EntryRef *entry_ref)
/*
* Flush out pending variable-numbered stats.
+ *
+ * If anytime_only is true, only flushes FLUSH_ANYTIME entries.
+ * This is safe to call inside transactions.
+ *
+ * If anytime_only is false, flushes all entries.
*/
static bool
-pgstat_flush_pending_entries(bool nowait)
+pgstat_flush_pending_entries(bool nowait, bool anytime_only)
{
bool have_pending = false;
dlist_node *cur = NULL;
@@ -1377,8 +1386,22 @@ pgstat_flush_pending_entries(bool nowait)
Assert(!kind_info->fixed_amount);
Assert(kind_info->flush_pending_cb != NULL);
+ /* Skip transactional stats if we're in anytime_only mode */
+ if (anytime_only && kind_info->flush_mode == FLUSH_AT_TXN_BOUNDARY)
+ {
+ have_pending = true;
+
+ if (dlist_has_next(&pgStatPending, cur))
+ next = dlist_next_node(&pgStatPending, cur);
+ else
+ next = NULL;
+
+ cur = next;
+ continue;
+ }
+
/* flush the stats, if possible */
- did_flush = kind_info->flush_pending_cb(entry_ref, nowait);
+ did_flush = kind_info->flush_pending_cb(entry_ref, nowait, anytime_only);
Assert(did_flush || nowait);
@@ -1402,6 +1425,33 @@ pgstat_flush_pending_entries(bool nowait)
return have_pending;
}
+/*
+ * Flush fixed-amount stats.
+ *
+ * If anytime_only is true, only flushes FLUSH_ANYTIME stats (safe inside transactions).
+ * If anytime_only is false, flushes all stats with flush_static_cb.
+ */
+static bool
+pgstat_flush_fixed_stats(bool nowait, bool anytime_only)
+{
+ bool partial_flush = false;
+
+ for (PgStat_Kind kind = PGSTAT_KIND_MIN; kind <= PGSTAT_KIND_MAX; kind++)
+ {
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (!kind_info || !kind_info->flush_static_cb)
+ continue;
+
+ /* Skip transactional stats if we're in anytime_only mode */
+ if (anytime_only && kind_info->flush_mode == FLUSH_AT_TXN_BOUNDARY)
+ continue;
+
+ partial_flush |= kind_info->flush_static_cb(nowait, anytime_only);
+ }
+
+ return partial_flush;
+}
/* ------------------------------------------------------------
* Helper / infrastructure functions
@@ -2119,3 +2169,33 @@ assign_stats_fetch_consistency(int newval, void *extra)
if (pgstat_fetch_consistency != newval)
force_stats_snapshot_clear = true;
}
+
+/*
+ * Flushes only FLUSH_ANYTIME stats using non-blocking locks. Transactional
+ * stats (FLUSH_AT_TXN_BOUNDARY) remain pending until transaction boundary.
+ * Safe to call inside transactions.
+ */
+void
+pgstat_report_anytime_stat(bool force)
+{
+ bool nowait = !force;
+
+ pgstat_assert_is_up();
+
+ /* Flush stats outside of transaction boundary */
+ pgstat_flush_pending_entries(nowait, true);
+ pgstat_flush_fixed_stats(nowait, true);
+
+ pgstat_pending_anytime = false;
+}
+
+/*
+ * Timeout handler for flushing anytime stats.
+ */
+void
+AnytimeStatsUpdateTimeoutHandler(void)
+{
+ AnytimeStatsUpdateTimeoutPending = true;
+ InterruptPending = true;
+ SetLatch(MyLatch);
+}
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index f2f8d3ff75f..b09316d3ab3 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -31,6 +31,7 @@
#include "storage/procarray.h"
#include "utils/memutils.h"
#include "utils/pgstat_internal.h"
+#include "utils/timeout.h"
/*
* Backend statistics counts waiting to be flushed out. These counters may be
@@ -66,6 +67,9 @@ pgstat_count_backend_io_op_time(IOObject io_object, IOContext io_context,
INSTR_TIME_ADD(PendingBackendStats.pending_io.pending_times[io_object][io_context][io_op],
io_time);
+ /* Schedule next anytime stats update timeout */
+ pgstat_schedule_anytime_update();
+
backend_has_iostats = true;
pgstat_report_fixed = true;
}
@@ -82,6 +86,9 @@ pgstat_count_backend_io_op(IOObject io_object, IOContext io_context,
PendingBackendStats.pending_io.counts[io_object][io_context][io_op] += cnt;
PendingBackendStats.pending_io.bytes[io_object][io_context][io_op] += bytes;
+ /* Schedule next anytime stats update timeout */
+ pgstat_schedule_anytime_update();
+
backend_has_iostats = true;
pgstat_report_fixed = true;
}
@@ -268,7 +275,7 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
* if some statistics could not be flushed due to lock contention.
*/
bool
-pgstat_flush_backend(bool nowait, bits32 flags)
+pgstat_flush_backend(bool nowait, bits32 flags, bool anytime_only)
{
PgStat_EntryRef *entry_ref;
bool has_pending_data = false;
@@ -311,9 +318,9 @@ pgstat_flush_backend(bool nowait, bits32 flags)
* If some stats could not be flushed due to lock contention, return true.
*/
bool
-pgstat_backend_flush_cb(bool nowait)
+pgstat_backend_flush_cb(bool nowait, bool anytime_only)
{
- return pgstat_flush_backend(nowait, PGSTAT_BACKEND_FLUSH_ALL);
+ return pgstat_flush_backend(nowait, PGSTAT_BACKEND_FLUSH_ALL, anytime_only);
}
/*
diff --git a/src/backend/utils/activity/pgstat_bgwriter.c b/src/backend/utils/activity/pgstat_bgwriter.c
index ed2fd801189..1c5f0c3ec40 100644
--- a/src/backend/utils/activity/pgstat_bgwriter.c
+++ b/src/backend/utils/activity/pgstat_bgwriter.c
@@ -61,7 +61,7 @@ pgstat_report_bgwriter(void)
/*
* Report IO statistics
*/
- pgstat_flush_io(false);
+ pgstat_flush_io(false, true);
}
/*
diff --git a/src/backend/utils/activity/pgstat_checkpointer.c b/src/backend/utils/activity/pgstat_checkpointer.c
index 1f70194b7a7..2d89a082464 100644
--- a/src/backend/utils/activity/pgstat_checkpointer.c
+++ b/src/backend/utils/activity/pgstat_checkpointer.c
@@ -68,7 +68,7 @@ pgstat_report_checkpointer(void)
/*
* Report IO statistics
*/
- pgstat_flush_io(false);
+ pgstat_flush_io(false, true);
}
/*
diff --git a/src/backend/utils/activity/pgstat_database.c b/src/backend/utils/activity/pgstat_database.c
index 933dcb5cae5..8e86df60461 100644
--- a/src/backend/utils/activity/pgstat_database.c
+++ b/src/backend/utils/activity/pgstat_database.c
@@ -435,7 +435,7 @@ pgstat_reset_database_timestamp(Oid dboid, TimestampTz ts)
* false without flushing the entry. Otherwise returns true.
*/
bool
-pgstat_database_flush_cb(PgStat_EntryRef *entry_ref, bool nowait)
+pgstat_database_flush_cb(PgStat_EntryRef *entry_ref, bool nowait, bool anytime_only)
{
PgStatShared_Database *sharedent;
PgStat_StatDBEntry *pendingent;
diff --git a/src/backend/utils/activity/pgstat_function.c b/src/backend/utils/activity/pgstat_function.c
index e6b84283c6c..5ba4958382f 100644
--- a/src/backend/utils/activity/pgstat_function.c
+++ b/src/backend/utils/activity/pgstat_function.c
@@ -190,11 +190,13 @@ pgstat_end_function_usage(PgStat_FunctionCallUsage *fcu, bool finalize)
* false without flushing the entry. Otherwise returns true.
*/
bool
-pgstat_function_flush_cb(PgStat_EntryRef *entry_ref, bool nowait)
+pgstat_function_flush_cb(PgStat_EntryRef *entry_ref, bool nowait, bool anytime_only)
{
PgStat_FunctionCounts *localent;
PgStatShared_Function *shfuncent;
+ Assert(!anytime_only);
+
localent = (PgStat_FunctionCounts *) entry_ref->pending;
shfuncent = (PgStatShared_Function *) entry_ref->shared_stats;
diff --git a/src/backend/utils/activity/pgstat_io.c b/src/backend/utils/activity/pgstat_io.c
index 28de24538dc..7cd32900236 100644
--- a/src/backend/utils/activity/pgstat_io.c
+++ b/src/backend/utils/activity/pgstat_io.c
@@ -19,6 +19,7 @@
#include "executor/instrument.h"
#include "storage/bufmgr.h"
#include "utils/pgstat_internal.h"
+#include "utils/timeout.h"
static PgStat_PendingIO PendingIOStats;
static bool have_iostats = false;
@@ -79,6 +80,9 @@ pgstat_count_io_op(IOObject io_object, IOContext io_context, IOOp io_op,
/* Add the per-backend counts */
pgstat_count_backend_io_op(io_object, io_context, io_op, cnt, bytes);
+ /* Schedule next anytime stats update timeout */
+ pgstat_schedule_anytime_update();
+
have_iostats = true;
pgstat_report_fixed = true;
}
@@ -172,9 +176,9 @@ pgstat_fetch_stat_io(void)
* Simpler wrapper of pgstat_io_flush_cb()
*/
void
-pgstat_flush_io(bool nowait)
+pgstat_flush_io(bool nowait, bool anytime_only)
{
- (void) pgstat_io_flush_cb(nowait);
+ (void) pgstat_io_flush_cb(nowait, anytime_only);
}
/*
@@ -186,7 +190,7 @@ pgstat_flush_io(bool nowait)
* acquired. Otherwise, return false.
*/
bool
-pgstat_io_flush_cb(bool nowait)
+pgstat_io_flush_cb(bool nowait, bool anytime_only)
{
LWLock *bktype_lock;
PgStat_BktypeIO *bktype_shstats;
diff --git a/src/backend/utils/activity/pgstat_relation.c b/src/backend/utils/activity/pgstat_relation.c
index bc8c43b96aa..04d21483d93 100644
--- a/src/backend/utils/activity/pgstat_relation.c
+++ b/src/backend/utils/activity/pgstat_relation.c
@@ -267,8 +267,8 @@ pgstat_report_vacuum(Relation rel, PgStat_Counter livetuples,
* is done -- which will likely vacuum many relations -- or until the
* VACUUM command has processed all tables and committed.
*/
- pgstat_flush_io(false);
- (void) pgstat_flush_backend(false, PGSTAT_BACKEND_FLUSH_IO);
+ pgstat_flush_io(false, true);
+ (void) pgstat_flush_backend(false, PGSTAT_BACKEND_FLUSH_IO, true);
}
/*
@@ -362,8 +362,8 @@ pgstat_report_analyze(Relation rel,
pgstat_unlock_entry(entry_ref);
/* see pgstat_report_vacuum() */
- pgstat_flush_io(false);
- (void) pgstat_flush_backend(false, PGSTAT_BACKEND_FLUSH_IO);
+ pgstat_flush_io(false, true);
+ (void) pgstat_flush_backend(false, PGSTAT_BACKEND_FLUSH_IO, true);
}
/*
@@ -812,7 +812,7 @@ pgstat_twophase_postabort(FullTransactionId fxid, uint16 info,
* entry when successfully flushing.
*/
bool
-pgstat_relation_flush_cb(PgStat_EntryRef *entry_ref, bool nowait)
+pgstat_relation_flush_cb(PgStat_EntryRef *entry_ref, bool nowait, bool anytime_only)
{
Oid dboid;
PgStat_TableStatus *lstats; /* pending stats entry */
@@ -820,6 +820,8 @@ pgstat_relation_flush_cb(PgStat_EntryRef *entry_ref, bool nowait)
PgStat_StatTabEntry *tabentry; /* table entry of shared stats */
PgStat_StatDBEntry *dbentry; /* pending database entry */
+ Assert(!anytime_only);
+
dboid = entry_ref->shared_entry->key.dboid;
lstats = (PgStat_TableStatus *) entry_ref->pending;
shtabstats = (PgStatShared_Relation *) entry_ref->shared_stats;
diff --git a/src/backend/utils/activity/pgstat_slru.c b/src/backend/utils/activity/pgstat_slru.c
index 2190f388eae..bf8a4d58673 100644
--- a/src/backend/utils/activity/pgstat_slru.c
+++ b/src/backend/utils/activity/pgstat_slru.c
@@ -19,6 +19,7 @@
#include "utils/pgstat_internal.h"
#include "utils/timestamp.h"
+#include "utils/timeout.h"
static inline PgStat_SLRUStats *get_slru_entry(int slru_idx);
@@ -139,7 +140,7 @@ pgstat_get_slru_index(const char *name)
* acquired. Otherwise return false.
*/
bool
-pgstat_slru_flush_cb(bool nowait)
+pgstat_slru_flush_cb(bool nowait, bool anytime_only)
{
PgStatShared_SLRU *stats_shmem = &pgStatLocal.shmem->slru;
int i;
@@ -223,6 +224,9 @@ get_slru_entry(int slru_idx)
Assert((slru_idx >= 0) && (slru_idx < SLRU_NUM_ELEMENTS));
+ /* Schedule next anytime stats update timeout */
+ pgstat_schedule_anytime_update();
+
have_slrustats = true;
pgstat_report_fixed = true;
diff --git a/src/backend/utils/activity/pgstat_subscription.c b/src/backend/utils/activity/pgstat_subscription.c
index 500b1899188..c4614817966 100644
--- a/src/backend/utils/activity/pgstat_subscription.c
+++ b/src/backend/utils/activity/pgstat_subscription.c
@@ -116,11 +116,13 @@ pgstat_fetch_stat_subscription(Oid subid)
* false without flushing the entry. Otherwise returns true.
*/
bool
-pgstat_subscription_flush_cb(PgStat_EntryRef *entry_ref, bool nowait)
+pgstat_subscription_flush_cb(PgStat_EntryRef *entry_ref, bool nowait, bool anytime_only)
{
PgStat_BackendSubEntry *localent;
PgStatShared_Subscription *shsubent;
+ Assert(!anytime_only);
+
localent = (PgStat_BackendSubEntry *) entry_ref->pending;
shsubent = (PgStatShared_Subscription *) entry_ref->shared_stats;
diff --git a/src/backend/utils/activity/pgstat_wal.c b/src/backend/utils/activity/pgstat_wal.c
index 183e0a7a97b..2c2f3f10e10 100644
--- a/src/backend/utils/activity/pgstat_wal.c
+++ b/src/backend/utils/activity/pgstat_wal.c
@@ -51,12 +51,12 @@ pgstat_report_wal(bool force)
nowait = !force;
/* flush wal stats */
- (void) pgstat_wal_flush_cb(nowait);
- pgstat_flush_backend(nowait, PGSTAT_BACKEND_FLUSH_WAL);
+ (void) pgstat_wal_flush_cb(nowait, true);
+ (void) pgstat_flush_backend(nowait, PGSTAT_BACKEND_FLUSH_WAL, true);
/* flush IO stats */
- pgstat_flush_io(nowait);
- (void) pgstat_flush_backend(nowait, PGSTAT_BACKEND_FLUSH_IO);
+ pgstat_flush_io(nowait, true);
+ (void) pgstat_flush_backend(nowait, PGSTAT_BACKEND_FLUSH_IO, true);
}
/*
@@ -88,7 +88,7 @@ pgstat_wal_have_pending(void)
* acquired. Otherwise return false.
*/
bool
-pgstat_wal_flush_cb(bool nowait)
+pgstat_wal_flush_cb(bool nowait, bool anytime_only)
{
PgStatShared_Wal *stats_shmem = &pgStatLocal.shmem->wal;
WalUsage wal_usage_diff = {0};
diff --git a/src/backend/utils/init/globals.c b/src/backend/utils/init/globals.c
index 36ad708b360..ad44826c39e 100644
--- a/src/backend/utils/init/globals.c
+++ b/src/backend/utils/init/globals.c
@@ -40,6 +40,7 @@ volatile sig_atomic_t IdleSessionTimeoutPending = false;
volatile sig_atomic_t ProcSignalBarrierPending = false;
volatile sig_atomic_t LogMemoryContextPending = false;
volatile sig_atomic_t IdleStatsUpdateTimeoutPending = false;
+volatile sig_atomic_t AnytimeStatsUpdateTimeoutPending = false;
volatile uint32 InterruptHoldoffCount = 0;
volatile uint32 QueryCancelHoldoffCount = 0;
volatile uint32 CritSectionCount = 0;
diff --git a/src/backend/utils/init/postinit.c b/src/backend/utils/init/postinit.c
index b59e08605cc..eeeac1bf39a 100644
--- a/src/backend/utils/init/postinit.c
+++ b/src/backend/utils/init/postinit.c
@@ -64,6 +64,7 @@
#include "utils/injection_point.h"
#include "utils/memutils.h"
#include "utils/pg_locale.h"
+#include "utils/pgstat_internal.h"
#include "utils/portal.h"
#include "utils/ps_status.h"
#include "utils/snapmgr.h"
@@ -773,6 +774,8 @@ InitPostgres(const char *in_dbname, Oid dboid,
RegisterTimeout(CLIENT_CONNECTION_CHECK_TIMEOUT, ClientCheckTimeoutHandler);
RegisterTimeout(IDLE_STATS_UPDATE_TIMEOUT,
IdleStatsUpdateTimeoutHandler);
+ RegisterTimeout(ANYTIME_STATS_UPDATE_TIMEOUT,
+ AnytimeStatsUpdateTimeoutHandler);
}
/*
diff --git a/src/include/miscadmin.h b/src/include/miscadmin.h
index f16f35659b9..84e698da214 100644
--- a/src/include/miscadmin.h
+++ b/src/include/miscadmin.h
@@ -96,6 +96,7 @@ extern PGDLLIMPORT volatile sig_atomic_t IdleSessionTimeoutPending;
extern PGDLLIMPORT volatile sig_atomic_t ProcSignalBarrierPending;
extern PGDLLIMPORT volatile sig_atomic_t LogMemoryContextPending;
extern PGDLLIMPORT volatile sig_atomic_t IdleStatsUpdateTimeoutPending;
+extern PGDLLIMPORT volatile sig_atomic_t AnytimeStatsUpdateTimeoutPending;
extern PGDLLIMPORT volatile sig_atomic_t CheckClientConnectionPending;
extern PGDLLIMPORT volatile sig_atomic_t ClientConnectionLost;
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index fff7ecc2533..f0f546d419a 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -35,6 +35,9 @@
/* Default directory to store temporary statistics data in */
#define PG_STAT_TMP_DIR "pg_stat_tmp"
+/* Minimum interval non-forced stats flushes */
+#define PGSTAT_MIN_INTERVAL 1000
+
/* Values for track_functions GUC variable --- order is significant! */
typedef enum TrackFunctionsLevel
{
@@ -533,8 +536,24 @@ extern void pgstat_initialize(void);
/* Functions called from backends */
extern long pgstat_report_stat(bool force);
+extern void pgstat_report_anytime_stat(bool force);
extern void pgstat_force_next_flush(void);
+/*
+ * Schedule the next anytime stats update timeout.
+ *
+ * This should be called whenever accumulating statistics that support
+ * FLUSH_ANYTIME flushing mode.
+ */
+#define pgstat_schedule_anytime_update() \
+ do { \
+ if (IsUnderPostmaster && !pgstat_pending_anytime) \
+ { \
+ enable_timeout_after(ANYTIME_STATS_UPDATE_TIMEOUT, PGSTAT_MIN_INTERVAL); \
+ pgstat_pending_anytime = true; \
+ } \
+ } while (0)
+
extern void pgstat_reset_counters(void);
extern void pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid);
extern void pgstat_reset_of_kind(PgStat_Kind kind);
@@ -808,6 +827,8 @@ extern PgStat_WalStats *pgstat_fetch_stat_wal(void);
* Variables in pgstat.c
*/
+extern PGDLLIMPORT bool pgstat_pending_anytime;
+
/* GUC parameters */
extern PGDLLIMPORT bool pgstat_track_counts;
extern PGDLLIMPORT int pgstat_track_functions;
@@ -851,4 +872,5 @@ extern PGDLLIMPORT PgStat_Counter pgStatTransactionIdleTime;
/* updated by the traffic cop and in errfinish() */
extern PGDLLIMPORT SessionEndType pgStatSessionEndCause;
+
#endif /* PGSTAT_H */
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 9b8fbae00ed..607f4255268 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -224,6 +224,19 @@ typedef struct PgStat_SubXactStatus
PgStat_TableXactStatus *first; /* head of list for this subxact */
} PgStat_SubXactStatus;
+/*
+ * Flush mode for statistics kinds.
+ *
+ * FLUSH_AT_TXN_BOUNDARY has to be the first because we want it to be the
+ * default value.
+ */
+typedef enum PgStat_FlushMode
+{
+ FLUSH_AT_TXN_BOUNDARY, /* All fields can only be flushed at
+ * transaction boundary */
+ FLUSH_ANYTIME, /* All fields can be flushed anytime,
+ * including within transactions */
+} PgStat_FlushMode;
/*
* Metadata for a specific kind of statistics.
@@ -251,6 +264,16 @@ typedef struct PgStat_KindInfo
*/
bool track_entry_count:1;
+ /*
+ * The mode of when to flush stats. See PgStat_FlushMode for more details.
+ *
+ * This member only has meaning for statistics kinds that accumulate
+ * pending stats and use flush callbacks. For kinds that write directly to
+ * shared memory (e.g., archiver, bgwriter, checkpointer), this member has
+ * no effect.
+ */
+ PgStat_FlushMode flush_mode;
+
/*
* The size of an entry in the shared stats hash table (pointed to by
* PgStatShared_HashEntry->body). For fixed-numbered statistics, this is
@@ -297,8 +320,10 @@ typedef struct PgStat_KindInfo
* For variable-numbered stats: flush pending stats. Required if pending
* data is used. See flush_static_cb when dealing with stats data that
* that cannot use PgStat_EntryRef->pending.
+ *
+ * The anytime_only parameter indicates whether this is an anytime flush.
*/
- bool (*flush_pending_cb) (PgStat_EntryRef *sr, bool nowait);
+ bool (*flush_pending_cb) (PgStat_EntryRef *sr, bool nowait, bool anytime_only);
/*
* For variable-numbered stats: delete pending stats. Optional.
@@ -366,8 +391,10 @@ typedef struct PgStat_KindInfo
*
* "pgstat_report_fixed" needs to be set to trigger the flush of pending
* stats.
+ *
+ * The anytime_only parameter indicates whether this is an anytime flush.
*/
- bool (*flush_static_cb) (bool nowait);
+ bool (*flush_static_cb) (bool nowait, bool anytime_only);
/*
* For fixed-numbered statistics: Reset All.
@@ -677,6 +704,7 @@ extern PgStat_EntryRef *pgstat_fetch_pending_entry(PgStat_Kind kind,
extern void *pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid);
extern void pgstat_snapshot_fixed(PgStat_Kind kind);
+extern void AnytimeStatsUpdateTimeoutHandler(void);
/*
@@ -696,8 +724,8 @@ extern void pgstat_archiver_snapshot_cb(void);
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
-extern bool pgstat_flush_backend(bool nowait, bits32 flags);
-extern bool pgstat_backend_flush_cb(bool nowait);
+extern bool pgstat_flush_backend(bool nowait, bits32 flags, bool anytime_only);
+extern bool pgstat_backend_flush_cb(bool nowait, bool anytime_only);
extern void pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header,
TimestampTz ts);
@@ -729,7 +757,7 @@ extern void AtEOXact_PgStat_Database(bool isCommit, bool parallel);
extern PgStat_StatDBEntry *pgstat_prep_database_pending(Oid dboid);
extern void pgstat_reset_database_timestamp(Oid dboid, TimestampTz ts);
-extern bool pgstat_database_flush_cb(PgStat_EntryRef *entry_ref, bool nowait);
+extern bool pgstat_database_flush_cb(PgStat_EntryRef *entry_ref, bool nowait, bool anytime_only);
extern void pgstat_database_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts);
@@ -737,7 +765,7 @@ extern void pgstat_database_reset_timestamp_cb(PgStatShared_Common *header, Time
* Functions in pgstat_function.c
*/
-extern bool pgstat_function_flush_cb(PgStat_EntryRef *entry_ref, bool nowait);
+extern bool pgstat_function_flush_cb(PgStat_EntryRef *entry_ref, bool nowait, bool anytime_only);
extern void pgstat_function_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts);
@@ -745,9 +773,9 @@ extern void pgstat_function_reset_timestamp_cb(PgStatShared_Common *header, Time
* Functions in pgstat_io.c
*/
-extern void pgstat_flush_io(bool nowait);
+extern void pgstat_flush_io(bool nowait, bool anytime_only);
-extern bool pgstat_io_flush_cb(bool nowait);
+extern bool pgstat_io_flush_cb(bool nowait, bool anytime_only);
extern void pgstat_io_init_shmem_cb(void *stats);
extern void pgstat_io_reset_all_cb(TimestampTz ts);
extern void pgstat_io_snapshot_cb(void);
@@ -762,7 +790,7 @@ extern void AtEOSubXact_PgStat_Relations(PgStat_SubXactStatus *xact_state, bool
extern void AtPrepare_PgStat_Relations(PgStat_SubXactStatus *xact_state);
extern void PostPrepare_PgStat_Relations(PgStat_SubXactStatus *xact_state);
-extern bool pgstat_relation_flush_cb(PgStat_EntryRef *entry_ref, bool nowait);
+extern bool pgstat_relation_flush_cb(PgStat_EntryRef *entry_ref, bool nowait, bool anytime_only);
extern void pgstat_relation_delete_pending_cb(PgStat_EntryRef *entry_ref);
extern void pgstat_relation_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts);
@@ -809,7 +837,7 @@ extern PgStatShared_Common *pgstat_init_entry(PgStat_Kind kind,
* Functions in pgstat_slru.c
*/
-extern bool pgstat_slru_flush_cb(bool nowait);
+extern bool pgstat_slru_flush_cb(bool nowait, bool anytime_only);
extern void pgstat_slru_init_shmem_cb(void *stats);
extern void pgstat_slru_reset_all_cb(TimestampTz ts);
extern void pgstat_slru_snapshot_cb(void);
@@ -820,7 +848,7 @@ extern void pgstat_slru_snapshot_cb(void);
*/
extern void pgstat_wal_init_backend_cb(void);
-extern bool pgstat_wal_flush_cb(bool nowait);
+extern bool pgstat_wal_flush_cb(bool nowait, bool anytime_only);
extern void pgstat_wal_init_shmem_cb(void *stats);
extern void pgstat_wal_reset_all_cb(TimestampTz ts);
extern void pgstat_wal_snapshot_cb(void);
@@ -830,7 +858,7 @@ extern void pgstat_wal_snapshot_cb(void);
* Functions in pgstat_subscription.c
*/
-extern bool pgstat_subscription_flush_cb(PgStat_EntryRef *entry_ref, bool nowait);
+extern bool pgstat_subscription_flush_cb(PgStat_EntryRef *entry_ref, bool nowait, bool anytime_only);
extern void pgstat_subscription_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts);
diff --git a/src/include/utils/timeout.h b/src/include/utils/timeout.h
index 0965b590b34..10723bb664c 100644
--- a/src/include/utils/timeout.h
+++ b/src/include/utils/timeout.h
@@ -35,6 +35,7 @@ typedef enum TimeoutId
IDLE_SESSION_TIMEOUT,
IDLE_STATS_UPDATE_TIMEOUT,
CLIENT_CONNECTION_CHECK_TIMEOUT,
+ ANYTIME_STATS_UPDATE_TIMEOUT,
STARTUP_PROGRESS_TIMEOUT,
/* First user-definable timeout reason */
USER_TIMEOUT,
diff --git a/src/test/modules/test_custom_stats/test_custom_var_stats.c b/src/test/modules/test_custom_stats/test_custom_var_stats.c
index 64a8fe63cce..bc0b5d6e0eb 100644
--- a/src/test/modules/test_custom_stats/test_custom_var_stats.c
+++ b/src/test/modules/test_custom_stats/test_custom_var_stats.c
@@ -83,7 +83,7 @@ static dsa_area *custom_stats_description_dsa = NULL;
/* Flush callback: merge pending stats into shared memory */
static bool test_custom_stats_var_flush_pending_cb(PgStat_EntryRef *entry_ref,
- bool nowait);
+ bool nowait, bool anytime_only);
/* Serialization callback: write auxiliary entry data */
static void test_custom_stats_var_to_serialized_data(const PgStat_HashKey *key,
@@ -150,7 +150,7 @@ _PG_init(void)
* Returns false only if nowait=true and lock acquisition fails.
*/
static bool
-test_custom_stats_var_flush_pending_cb(PgStat_EntryRef *entry_ref, bool nowait)
+test_custom_stats_var_flush_pending_cb(PgStat_EntryRef *entry_ref, bool nowait, bool anytime_only)
{
PgStat_StatCustomVarEntry *pending_entry;
PgStatShared_CustomVarEntry *shared_entry;
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 241945734ec..1dbc4b96f51 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -2271,6 +2271,7 @@ PgStat_Counter
PgStat_EntryRef
PgStat_EntryRefHashEntry
PgStat_FetchConsistency
+PgStat_FlushMode
PgStat_FunctionCallUsage
PgStat_FunctionCounts
PgStat_HashKey
--
2.34.1
--aq/6bi8L6WORnI+9
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v9-0002-Add-anytime-flush-tests-for-custom-stats.patch"
^ permalink raw reply [nested|flat] 12+ messages in thread
* [PATCH v10 1/5] Add pgstat_report_anytime_stat() for periodic stats flushing
@ 2026-01-05 09:41 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 12+ messages in thread
From: Bertrand Drouvot @ 2026-01-05 09:41 UTC (permalink / raw)
Long running transactions can accumulate significant statistics (WAL, IO, ...)
that remain unflushed until the transaction ends. This delays visibility of
resource usage in monitoring views like pg_stat_io and pg_stat_wal and produces
spikes when flushed.
This commit introduces pgstat_report_anytime_stat(), which flushes
non transactional statistics even inside active transactions. A new timeout
handler fires every second (if enabled while adding pending stats) to call this
function, ensuring timely stats visibility without waiting for transaction completion.
Implementation details:
- Add PgStat_FlushMode enum to classify stats kinds:
* FLUSH_ANYTIME: Stats that can always be flushed (WAL, IO, ...)
* FLUSH_AT_TXN_BOUNDARY: Stats requiring transaction boundaries
- Modify pgstat_flush_pending_entries() and pgstat_flush_fixed_stats()
to accept a boolean anytime_only parameter:
* When false: flushes all stats (existing behavior)
* When true: flushes only FLUSH_ANYTIME stats and skips FLUSH_AT_TXN_BOUNDARY stats
- The flush_pending_cb and flush_static_cb callbacks now receive an anytime_only
boolean parameter. Most of the time it's not used (except for assertions), but it's
preparatory work for moving the relations stats to anytime (without introducin
a new callback).
- Add pgstat_schedule_anytime_update() macro to schedule the next anytime flush,
relying on PGSTAT_MIN_INTERVAL
The force parameter in pgstat_report_anytime_stat() is currently unused (always
called with force=false) but reserved for future use cases requiring immediate
flushing.
---
src/backend/access/transam/xlog.c | 6 +
src/backend/postmaster/bgwriter.c | 9 +-
src/backend/postmaster/checkpointer.c | 10 +-
src/backend/postmaster/startup.c | 2 +
src/backend/postmaster/walsummarizer.c | 9 +-
src/backend/postmaster/walwriter.c | 9 +-
src/backend/replication/walreceiver.c | 9 +-
src/backend/replication/walsender.c | 8 +-
src/backend/tcop/postgres.c | 12 ++
src/backend/utils/activity/pgstat.c | 121 +++++++++++++++---
src/backend/utils/activity/pgstat_backend.c | 13 +-
src/backend/utils/activity/pgstat_bgwriter.c | 2 +-
.../utils/activity/pgstat_checkpointer.c | 2 +-
src/backend/utils/activity/pgstat_database.c | 2 +-
src/backend/utils/activity/pgstat_function.c | 4 +-
src/backend/utils/activity/pgstat_io.c | 10 +-
src/backend/utils/activity/pgstat_relation.c | 12 +-
src/backend/utils/activity/pgstat_slru.c | 6 +-
.../utils/activity/pgstat_subscription.c | 4 +-
src/backend/utils/activity/pgstat_wal.c | 10 +-
src/backend/utils/init/globals.c | 1 +
src/backend/utils/init/postinit.c | 3 +
src/include/miscadmin.h | 1 +
src/include/pgstat.h | 22 ++++
src/include/utils/pgstat_internal.h | 52 ++++++--
src/include/utils/timeout.h | 1 +
.../test_custom_stats/test_custom_var_stats.c | 4 +-
src/tools/pgindent/typedefs.list | 1 +
28 files changed, 279 insertions(+), 66 deletions(-)
10.5% src/backend/postmaster/
5.8% src/backend/replication/
51.0% src/backend/utils/activity/
5.8% src/backend/
18.7% src/include/utils/
6.6% src/include/
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 13cce9b49f1..cf29fc91f70 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -1085,6 +1085,9 @@ XLogInsertRecord(XLogRecData *rdata,
pgWalUsage.wal_fpi += num_fpi;
pgWalUsage.wal_fpi_bytes += fpi_bytes;
+ /* Schedule next anytime stats update timeout */
+ pgstat_schedule_anytime_update();
+
/* Required for the flush of pending stats WAL data */
pgstat_report_fixed = true;
}
@@ -2066,6 +2069,9 @@ AdvanceXLInsertBuffer(XLogRecPtr upto, TimeLineID tli, bool opportunistic)
pgWalUsage.wal_buffers_full++;
TRACE_POSTGRESQL_WAL_BUFFER_WRITE_DIRTY_DONE();
+ /* Schedule next anytime stats update timeout */
+ pgstat_schedule_anytime_update();
+
/*
* Required for the flush of pending stats WAL data, per
* update of pgWalUsage.
diff --git a/src/backend/postmaster/bgwriter.c b/src/backend/postmaster/bgwriter.c
index 0956bd39a85..059c601c3b8 100644
--- a/src/backend/postmaster/bgwriter.c
+++ b/src/backend/postmaster/bgwriter.c
@@ -49,7 +49,9 @@
#include "storage/smgr.h"
#include "storage/standby.h"
#include "utils/memutils.h"
+#include "utils/pgstat_internal.h"
#include "utils/resowner.h"
+#include "utils/timeout.h"
#include "utils/timestamp.h"
/*
@@ -103,7 +105,7 @@ BackgroundWriterMain(const void *startup_data, size_t startup_data_len)
pqsignal(SIGINT, SIG_IGN);
pqsignal(SIGTERM, SignalHandlerForShutdownRequest);
/* SIGQUIT handler was already set up by InitPostmasterChild */
- pqsignal(SIGALRM, SIG_IGN);
+ InitializeTimeouts(); /* establishes SIGALRM handler */
pqsignal(SIGPIPE, SIG_IGN);
pqsignal(SIGUSR1, procsignal_sigusr1_handler);
pqsignal(SIGUSR2, SIG_IGN);
@@ -113,6 +115,11 @@ BackgroundWriterMain(const void *startup_data, size_t startup_data_len)
*/
pqsignal(SIGCHLD, SIG_DFL);
+ /*
+ * Register timeouts needed
+ */
+ RegisterTimeout(ANYTIME_STATS_UPDATE_TIMEOUT, AnytimeStatsUpdateTimeoutHandler);
+
/*
* We just started, assume there has been either a shutdown or
* end-of-recovery snapshot.
diff --git a/src/backend/postmaster/checkpointer.c b/src/backend/postmaster/checkpointer.c
index e03c19123bc..e11c4b099c8 100644
--- a/src/backend/postmaster/checkpointer.c
+++ b/src/backend/postmaster/checkpointer.c
@@ -66,8 +66,9 @@
#include "utils/acl.h"
#include "utils/guc.h"
#include "utils/memutils.h"
+#include "utils/pgstat_internal.h"
#include "utils/resowner.h"
-
+#include "utils/timeout.h"
/*----------
* Shared memory area for communication between checkpointer and backends
@@ -215,7 +216,7 @@ CheckpointerMain(const void *startup_data, size_t startup_data_len)
pqsignal(SIGINT, ReqShutdownXLOG);
pqsignal(SIGTERM, SIG_IGN); /* ignore SIGTERM */
/* SIGQUIT handler was already set up by InitPostmasterChild */
- pqsignal(SIGALRM, SIG_IGN);
+ InitializeTimeouts(); /* establishes SIGALRM handler */
pqsignal(SIGPIPE, SIG_IGN);
pqsignal(SIGUSR1, procsignal_sigusr1_handler);
pqsignal(SIGUSR2, SignalHandlerForShutdownRequest);
@@ -225,6 +226,11 @@ CheckpointerMain(const void *startup_data, size_t startup_data_len)
*/
pqsignal(SIGCHLD, SIG_DFL);
+ /*
+ * Register timeouts needed
+ */
+ RegisterTimeout(ANYTIME_STATS_UPDATE_TIMEOUT, AnytimeStatsUpdateTimeoutHandler);
+
/*
* Initialize so that first time-driven event happens at the correct time.
*/
diff --git a/src/backend/postmaster/startup.c b/src/backend/postmaster/startup.c
index cdbe53dd262..4954fe425b7 100644
--- a/src/backend/postmaster/startup.c
+++ b/src/backend/postmaster/startup.c
@@ -32,6 +32,7 @@
#include "storage/standby.h"
#include "utils/guc.h"
#include "utils/memutils.h"
+#include "utils/pgstat_internal.h"
#include "utils/timeout.h"
@@ -245,6 +246,7 @@ StartupProcessMain(const void *startup_data, size_t startup_data_len)
RegisterTimeout(STANDBY_DEADLOCK_TIMEOUT, StandbyDeadLockHandler);
RegisterTimeout(STANDBY_TIMEOUT, StandbyTimeoutHandler);
RegisterTimeout(STANDBY_LOCK_TIMEOUT, StandbyLockTimeoutHandler);
+ RegisterTimeout(ANYTIME_STATS_UPDATE_TIMEOUT, AnytimeStatsUpdateTimeoutHandler);
/*
* Unblock signals (they were blocked when the postmaster forked us)
diff --git a/src/backend/postmaster/walsummarizer.c b/src/backend/postmaster/walsummarizer.c
index 742137edad6..f1bae9d23d6 100644
--- a/src/backend/postmaster/walsummarizer.c
+++ b/src/backend/postmaster/walsummarizer.c
@@ -48,6 +48,8 @@
#include "storage/shmem.h"
#include "utils/guc.h"
#include "utils/memutils.h"
+#include "utils/pgstat_internal.h"
+#include "utils/timeout.h"
#include "utils/wait_event.h"
/*
@@ -246,7 +248,7 @@ WalSummarizerMain(const void *startup_data, size_t startup_data_len)
pqsignal(SIGINT, SIG_IGN); /* no query to cancel */
pqsignal(SIGTERM, SignalHandlerForShutdownRequest);
/* SIGQUIT handler was already set up by InitPostmasterChild */
- pqsignal(SIGALRM, SIG_IGN);
+ InitializeTimeouts(); /* establishes SIGALRM handler */
pqsignal(SIGPIPE, SIG_IGN);
pqsignal(SIGUSR1, procsignal_sigusr1_handler);
pqsignal(SIGUSR2, SIG_IGN); /* not used */
@@ -268,6 +270,11 @@ WalSummarizerMain(const void *startup_data, size_t startup_data_len)
*/
pqsignal(SIGCHLD, SIG_DFL);
+ /*
+ * Register timeouts needed
+ */
+ RegisterTimeout(ANYTIME_STATS_UPDATE_TIMEOUT, AnytimeStatsUpdateTimeoutHandler);
+
/*
* If an exception is encountered, processing resumes here.
*/
diff --git a/src/backend/postmaster/walwriter.c b/src/backend/postmaster/walwriter.c
index 7c0e2809c17..bcf59227a00 100644
--- a/src/backend/postmaster/walwriter.c
+++ b/src/backend/postmaster/walwriter.c
@@ -61,7 +61,9 @@
#include "storage/smgr.h"
#include "utils/hsearch.h"
#include "utils/memutils.h"
+#include "utils/pgstat_internal.h"
#include "utils/resowner.h"
+#include "utils/timeout.h"
/*
@@ -103,7 +105,7 @@ WalWriterMain(const void *startup_data, size_t startup_data_len)
pqsignal(SIGINT, SIG_IGN); /* no query to cancel */
pqsignal(SIGTERM, SignalHandlerForShutdownRequest);
/* SIGQUIT handler was already set up by InitPostmasterChild */
- pqsignal(SIGALRM, SIG_IGN);
+ InitializeTimeouts(); /* establishes SIGALRM handler */
pqsignal(SIGPIPE, SIG_IGN);
pqsignal(SIGUSR1, procsignal_sigusr1_handler);
pqsignal(SIGUSR2, SIG_IGN); /* not used */
@@ -113,6 +115,11 @@ WalWriterMain(const void *startup_data, size_t startup_data_len)
*/
pqsignal(SIGCHLD, SIG_DFL);
+ /*
+ * Register timeouts needed
+ */
+ RegisterTimeout(ANYTIME_STATS_UPDATE_TIMEOUT, AnytimeStatsUpdateTimeoutHandler);
+
/*
* Create a memory context that we will do all our work in. We do this so
* that we can reset the context during error recovery and thereby avoid
diff --git a/src/backend/replication/walreceiver.c b/src/backend/replication/walreceiver.c
index 7c1b8757d7d..aecc7a127e6 100644
--- a/src/backend/replication/walreceiver.c
+++ b/src/backend/replication/walreceiver.c
@@ -77,7 +77,9 @@
#include "utils/builtins.h"
#include "utils/guc.h"
#include "utils/pg_lsn.h"
+#include "utils/pgstat_internal.h"
#include "utils/ps_status.h"
+#include "utils/timeout.h"
#include "utils/timestamp.h"
@@ -252,7 +254,7 @@ WalReceiverMain(const void *startup_data, size_t startup_data_len)
pqsignal(SIGINT, SIG_IGN);
pqsignal(SIGTERM, die); /* request shutdown */
/* SIGQUIT handler was already set up by InitPostmasterChild */
- pqsignal(SIGALRM, SIG_IGN);
+ InitializeTimeouts(); /* establishes SIGALRM handler */
pqsignal(SIGPIPE, SIG_IGN);
pqsignal(SIGUSR1, procsignal_sigusr1_handler);
pqsignal(SIGUSR2, SIG_IGN);
@@ -260,6 +262,11 @@ WalReceiverMain(const void *startup_data, size_t startup_data_len)
/* Reset some signals that are accepted by postmaster but not here */
pqsignal(SIGCHLD, SIG_DFL);
+ /*
+ * Register timeouts needed
+ */
+ RegisterTimeout(ANYTIME_STATS_UPDATE_TIMEOUT, AnytimeStatsUpdateTimeoutHandler);
+
/* Load the libpq-specific functions */
load_file("libpqwalreceiver", false);
if (WalReceiverFunctions == NULL)
diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c
index 2cde8ebc729..a7214d0dc6f 100644
--- a/src/backend/replication/walsender.c
+++ b/src/backend/replication/walsender.c
@@ -1987,8 +1987,8 @@ WalSndWaitForWal(XLogRecPtr loc)
if (TimestampDifferenceExceeds(last_flush, now,
WALSENDER_STATS_FLUSH_INTERVAL))
{
- pgstat_flush_io(false);
- (void) pgstat_flush_backend(false, PGSTAT_BACKEND_FLUSH_IO);
+ pgstat_flush_io(false, true);
+ (void) pgstat_flush_backend(false, PGSTAT_BACKEND_FLUSH_IO, true);
last_flush = now;
}
@@ -3016,8 +3016,8 @@ WalSndLoop(WalSndSendDataCallback send_data)
if (TimestampDifferenceExceeds(last_flush, now,
WALSENDER_STATS_FLUSH_INTERVAL))
{
- pgstat_flush_io(false);
- (void) pgstat_flush_backend(false, PGSTAT_BACKEND_FLUSH_IO);
+ pgstat_flush_io(false, true);
+ (void) pgstat_flush_backend(false, PGSTAT_BACKEND_FLUSH_IO, true);
last_flush = now;
}
diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c
index d01a09dd0c4..8c30efa2443 100644
--- a/src/backend/tcop/postgres.c
+++ b/src/backend/tcop/postgres.c
@@ -3564,6 +3564,18 @@ ProcessInterrupts(void)
pgstat_report_stat(true);
}
+ /*
+ * Flush stats outside of transaction boundary if the timeout fired.
+ * Unlike transactional stats, these can be flushed even inside a running
+ * transaction.
+ */
+ if (AnytimeStatsUpdateTimeoutPending)
+ {
+ AnytimeStatsUpdateTimeoutPending = false;
+
+ pgstat_report_anytime_stat(false);
+ }
+
if (ProcSignalBarrierPending)
ProcessProcSignalBarrier();
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index 11bb71cad5a..ddd331e2c81 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -108,10 +108,12 @@
#include "pgstat.h"
#include "storage/fd.h"
#include "storage/ipc.h"
+#include "storage/latch.h"
#include "storage/lwlock.h"
#include "utils/guc_hooks.h"
#include "utils/memutils.h"
#include "utils/pgstat_internal.h"
+#include "utils/timeout.h"
#include "utils/timestamp.h"
@@ -122,8 +124,6 @@
* ----------
*/
-/* minimum interval non-forced stats flushes.*/
-#define PGSTAT_MIN_INTERVAL 1000
/* how long until to block flushing pending stats updates */
#define PGSTAT_MAX_INTERVAL 60000
/* when to call pgstat_report_stat() again, even when idle */
@@ -187,7 +187,8 @@ static void pgstat_init_snapshot_fixed(void);
static void pgstat_reset_after_failure(void);
-static bool pgstat_flush_pending_entries(bool nowait);
+static bool pgstat_flush_pending_entries(bool nowait, bool anytime_only);
+static bool pgstat_flush_fixed_stats(bool nowait, bool anytime_only);
static void pgstat_prep_snapshot(void);
static void pgstat_build_snapshot(void);
@@ -218,6 +219,12 @@ PgStat_LocalState pgStatLocal;
*/
bool pgstat_report_fixed = false;
+/*
+ * Track when there is pending anytime flush to avoid relying on
+ * get_timeout_active() in hot pathes.
+ */
+bool pgstat_pending_anytime = false;
+
/* ----------
* Local data
*
@@ -288,6 +295,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = true,
+ .flush_mode = FLUSH_AT_TXN_BOUNDARY,
/* so pg_stat_database entries can be seen in all databases */
.accessed_across_databases = true,
@@ -305,6 +313,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = true,
+ .flush_mode = FLUSH_AT_TXN_BOUNDARY,
.shared_size = sizeof(PgStatShared_Relation),
.shared_data_off = offsetof(PgStatShared_Relation, stats),
@@ -321,6 +330,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = true,
+ .flush_mode = FLUSH_AT_TXN_BOUNDARY,
.shared_size = sizeof(PgStatShared_Function),
.shared_data_off = offsetof(PgStatShared_Function, stats),
@@ -336,6 +346,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = true,
+ .flush_mode = FLUSH_AT_TXN_BOUNDARY,
.accessed_across_databases = true,
@@ -353,6 +364,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = true,
+ .flush_mode = FLUSH_AT_TXN_BOUNDARY,
/* so pg_stat_subscription_stats entries can be seen in all databases */
.accessed_across_databases = true,
@@ -370,6 +382,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = false,
+ .flush_mode = FLUSH_ANYTIME,
.accessed_across_databases = true,
@@ -436,6 +449,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = true,
.write_to_file = true,
+ .flush_mode = FLUSH_ANYTIME,
.snapshot_ctl_off = offsetof(PgStat_Snapshot, io),
.shared_ctl_off = offsetof(PgStat_ShmemControl, io),
@@ -453,6 +467,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = true,
.write_to_file = true,
+ .flush_mode = FLUSH_ANYTIME,
.snapshot_ctl_off = offsetof(PgStat_Snapshot, slru),
.shared_ctl_off = offsetof(PgStat_ShmemControl, slru),
@@ -470,6 +485,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = true,
.write_to_file = true,
+ .flush_mode = FLUSH_ANYTIME,
.snapshot_ctl_off = offsetof(PgStat_Snapshot, wal),
.shared_ctl_off = offsetof(PgStat_ShmemControl, wal),
@@ -775,23 +791,11 @@ pgstat_report_stat(bool force)
partial_flush = false;
/* flush of variable-numbered stats tracked in pending entries list */
- partial_flush |= pgstat_flush_pending_entries(nowait);
+ partial_flush |= pgstat_flush_pending_entries(nowait, false);
/* flush of other stats kinds */
if (pgstat_report_fixed)
- {
- for (PgStat_Kind kind = PGSTAT_KIND_MIN; kind <= PGSTAT_KIND_MAX; kind++)
- {
- const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
-
- if (!kind_info)
- continue;
- if (!kind_info->flush_static_cb)
- continue;
-
- partial_flush |= kind_info->flush_static_cb(nowait);
- }
- }
+ partial_flush |= pgstat_flush_fixed_stats(nowait, false);
last_flush = now;
@@ -1293,7 +1297,8 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
@@ -1345,9 +1350,14 @@ pgstat_delete_pending_entry(PgStat_EntryRef *entry_ref)
/*
* Flush out pending variable-numbered stats.
+ *
+ * If anytime_only is true, only flushes FLUSH_ANYTIME entries.
+ * This is safe to call inside transactions.
+ *
+ * If anytime_only is false, flushes all entries.
*/
static bool
-pgstat_flush_pending_entries(bool nowait)
+pgstat_flush_pending_entries(bool nowait, bool anytime_only)
{
bool have_pending = false;
dlist_node *cur = NULL;
@@ -1377,8 +1387,22 @@ pgstat_flush_pending_entries(bool nowait)
Assert(!kind_info->fixed_amount);
Assert(kind_info->flush_pending_cb != NULL);
+ /* Skip transactional stats if we're in anytime_only mode */
+ if (anytime_only && kind_info->flush_mode == FLUSH_AT_TXN_BOUNDARY)
+ {
+ have_pending = true;
+
+ if (dlist_has_next(&pgStatPending, cur))
+ next = dlist_next_node(&pgStatPending, cur);
+ else
+ next = NULL;
+
+ cur = next;
+ continue;
+ }
+
/* flush the stats, if possible */
- did_flush = kind_info->flush_pending_cb(entry_ref, nowait);
+ did_flush = kind_info->flush_pending_cb(entry_ref, nowait, anytime_only);
Assert(did_flush || nowait);
@@ -1402,6 +1426,33 @@ pgstat_flush_pending_entries(bool nowait)
return have_pending;
}
+/*
+ * Flush fixed-amount stats.
+ *
+ * If anytime_only is true, only flushes FLUSH_ANYTIME stats (safe inside transactions).
+ * If anytime_only is false, flushes all stats with flush_static_cb.
+ */
+static bool
+pgstat_flush_fixed_stats(bool nowait, bool anytime_only)
+{
+ bool partial_flush = false;
+
+ for (PgStat_Kind kind = PGSTAT_KIND_MIN; kind <= PGSTAT_KIND_MAX; kind++)
+ {
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (!kind_info || !kind_info->flush_static_cb)
+ continue;
+
+ /* Skip transactional stats if we're in anytime_only mode */
+ if (anytime_only && kind_info->flush_mode == FLUSH_AT_TXN_BOUNDARY)
+ continue;
+
+ partial_flush |= kind_info->flush_static_cb(nowait, anytime_only);
+ }
+
+ return partial_flush;
+}
/* ------------------------------------------------------------
* Helper / infrastructure functions
@@ -2119,3 +2170,33 @@ assign_stats_fetch_consistency(int newval, void *extra)
if (pgstat_fetch_consistency != newval)
force_stats_snapshot_clear = true;
}
+
+/*
+ * Flushes only FLUSH_ANYTIME stats using non-blocking locks. Transactional
+ * stats (FLUSH_AT_TXN_BOUNDARY) remain pending until transaction boundary.
+ * Safe to call inside transactions.
+ */
+void
+pgstat_report_anytime_stat(bool force)
+{
+ bool nowait = !force;
+
+ pgstat_assert_is_up();
+
+ /* Flush stats outside of transaction boundary */
+ pgstat_flush_pending_entries(nowait, true);
+ pgstat_flush_fixed_stats(nowait, true);
+
+ pgstat_pending_anytime = false;
+}
+
+/*
+ * Timeout handler for flushing anytime stats.
+ */
+void
+AnytimeStatsUpdateTimeoutHandler(void)
+{
+ AnytimeStatsUpdateTimeoutPending = true;
+ InterruptPending = true;
+ SetLatch(MyLatch);
+}
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index f2f8d3ff75f..b09316d3ab3 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -31,6 +31,7 @@
#include "storage/procarray.h"
#include "utils/memutils.h"
#include "utils/pgstat_internal.h"
+#include "utils/timeout.h"
/*
* Backend statistics counts waiting to be flushed out. These counters may be
@@ -66,6 +67,9 @@ pgstat_count_backend_io_op_time(IOObject io_object, IOContext io_context,
INSTR_TIME_ADD(PendingBackendStats.pending_io.pending_times[io_object][io_context][io_op],
io_time);
+ /* Schedule next anytime stats update timeout */
+ pgstat_schedule_anytime_update();
+
backend_has_iostats = true;
pgstat_report_fixed = true;
}
@@ -82,6 +86,9 @@ pgstat_count_backend_io_op(IOObject io_object, IOContext io_context,
PendingBackendStats.pending_io.counts[io_object][io_context][io_op] += cnt;
PendingBackendStats.pending_io.bytes[io_object][io_context][io_op] += bytes;
+ /* Schedule next anytime stats update timeout */
+ pgstat_schedule_anytime_update();
+
backend_has_iostats = true;
pgstat_report_fixed = true;
}
@@ -268,7 +275,7 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
* if some statistics could not be flushed due to lock contention.
*/
bool
-pgstat_flush_backend(bool nowait, bits32 flags)
+pgstat_flush_backend(bool nowait, bits32 flags, bool anytime_only)
{
PgStat_EntryRef *entry_ref;
bool has_pending_data = false;
@@ -311,9 +318,9 @@ pgstat_flush_backend(bool nowait, bits32 flags)
* If some stats could not be flushed due to lock contention, return true.
*/
bool
-pgstat_backend_flush_cb(bool nowait)
+pgstat_backend_flush_cb(bool nowait, bool anytime_only)
{
- return pgstat_flush_backend(nowait, PGSTAT_BACKEND_FLUSH_ALL);
+ return pgstat_flush_backend(nowait, PGSTAT_BACKEND_FLUSH_ALL, anytime_only);
}
/*
diff --git a/src/backend/utils/activity/pgstat_bgwriter.c b/src/backend/utils/activity/pgstat_bgwriter.c
index ed2fd801189..1c5f0c3ec40 100644
--- a/src/backend/utils/activity/pgstat_bgwriter.c
+++ b/src/backend/utils/activity/pgstat_bgwriter.c
@@ -61,7 +61,7 @@ pgstat_report_bgwriter(void)
/*
* Report IO statistics
*/
- pgstat_flush_io(false);
+ pgstat_flush_io(false, true);
}
/*
diff --git a/src/backend/utils/activity/pgstat_checkpointer.c b/src/backend/utils/activity/pgstat_checkpointer.c
index 1f70194b7a7..2d89a082464 100644
--- a/src/backend/utils/activity/pgstat_checkpointer.c
+++ b/src/backend/utils/activity/pgstat_checkpointer.c
@@ -68,7 +68,7 @@ pgstat_report_checkpointer(void)
/*
* Report IO statistics
*/
- pgstat_flush_io(false);
+ pgstat_flush_io(false, true);
}
/*
diff --git a/src/backend/utils/activity/pgstat_database.c b/src/backend/utils/activity/pgstat_database.c
index 933dcb5cae5..8e86df60461 100644
--- a/src/backend/utils/activity/pgstat_database.c
+++ b/src/backend/utils/activity/pgstat_database.c
@@ -435,7 +435,7 @@ pgstat_reset_database_timestamp(Oid dboid, TimestampTz ts)
* false without flushing the entry. Otherwise returns true.
*/
bool
-pgstat_database_flush_cb(PgStat_EntryRef *entry_ref, bool nowait)
+pgstat_database_flush_cb(PgStat_EntryRef *entry_ref, bool nowait, bool anytime_only)
{
PgStatShared_Database *sharedent;
PgStat_StatDBEntry *pendingent;
diff --git a/src/backend/utils/activity/pgstat_function.c b/src/backend/utils/activity/pgstat_function.c
index e6b84283c6c..5ba4958382f 100644
--- a/src/backend/utils/activity/pgstat_function.c
+++ b/src/backend/utils/activity/pgstat_function.c
@@ -190,11 +190,13 @@ pgstat_end_function_usage(PgStat_FunctionCallUsage *fcu, bool finalize)
* false without flushing the entry. Otherwise returns true.
*/
bool
-pgstat_function_flush_cb(PgStat_EntryRef *entry_ref, bool nowait)
+pgstat_function_flush_cb(PgStat_EntryRef *entry_ref, bool nowait, bool anytime_only)
{
PgStat_FunctionCounts *localent;
PgStatShared_Function *shfuncent;
+ Assert(!anytime_only);
+
localent = (PgStat_FunctionCounts *) entry_ref->pending;
shfuncent = (PgStatShared_Function *) entry_ref->shared_stats;
diff --git a/src/backend/utils/activity/pgstat_io.c b/src/backend/utils/activity/pgstat_io.c
index 28de24538dc..7cd32900236 100644
--- a/src/backend/utils/activity/pgstat_io.c
+++ b/src/backend/utils/activity/pgstat_io.c
@@ -19,6 +19,7 @@
#include "executor/instrument.h"
#include "storage/bufmgr.h"
#include "utils/pgstat_internal.h"
+#include "utils/timeout.h"
static PgStat_PendingIO PendingIOStats;
static bool have_iostats = false;
@@ -79,6 +80,9 @@ pgstat_count_io_op(IOObject io_object, IOContext io_context, IOOp io_op,
/* Add the per-backend counts */
pgstat_count_backend_io_op(io_object, io_context, io_op, cnt, bytes);
+ /* Schedule next anytime stats update timeout */
+ pgstat_schedule_anytime_update();
+
have_iostats = true;
pgstat_report_fixed = true;
}
@@ -172,9 +176,9 @@ pgstat_fetch_stat_io(void)
* Simpler wrapper of pgstat_io_flush_cb()
*/
void
-pgstat_flush_io(bool nowait)
+pgstat_flush_io(bool nowait, bool anytime_only)
{
- (void) pgstat_io_flush_cb(nowait);
+ (void) pgstat_io_flush_cb(nowait, anytime_only);
}
/*
@@ -186,7 +190,7 @@ pgstat_flush_io(bool nowait)
* acquired. Otherwise, return false.
*/
bool
-pgstat_io_flush_cb(bool nowait)
+pgstat_io_flush_cb(bool nowait, bool anytime_only)
{
LWLock *bktype_lock;
PgStat_BktypeIO *bktype_shstats;
diff --git a/src/backend/utils/activity/pgstat_relation.c b/src/backend/utils/activity/pgstat_relation.c
index bc8c43b96aa..04d21483d93 100644
--- a/src/backend/utils/activity/pgstat_relation.c
+++ b/src/backend/utils/activity/pgstat_relation.c
@@ -267,8 +267,8 @@ pgstat_report_vacuum(Relation rel, PgStat_Counter livetuples,
* is done -- which will likely vacuum many relations -- or until the
* VACUUM command has processed all tables and committed.
*/
- pgstat_flush_io(false);
- (void) pgstat_flush_backend(false, PGSTAT_BACKEND_FLUSH_IO);
+ pgstat_flush_io(false, true);
+ (void) pgstat_flush_backend(false, PGSTAT_BACKEND_FLUSH_IO, true);
}
/*
@@ -362,8 +362,8 @@ pgstat_report_analyze(Relation rel,
pgstat_unlock_entry(entry_ref);
/* see pgstat_report_vacuum() */
- pgstat_flush_io(false);
- (void) pgstat_flush_backend(false, PGSTAT_BACKEND_FLUSH_IO);
+ pgstat_flush_io(false, true);
+ (void) pgstat_flush_backend(false, PGSTAT_BACKEND_FLUSH_IO, true);
}
/*
@@ -812,7 +812,7 @@ pgstat_twophase_postabort(FullTransactionId fxid, uint16 info,
* entry when successfully flushing.
*/
bool
-pgstat_relation_flush_cb(PgStat_EntryRef *entry_ref, bool nowait)
+pgstat_relation_flush_cb(PgStat_EntryRef *entry_ref, bool nowait, bool anytime_only)
{
Oid dboid;
PgStat_TableStatus *lstats; /* pending stats entry */
@@ -820,6 +820,8 @@ pgstat_relation_flush_cb(PgStat_EntryRef *entry_ref, bool nowait)
PgStat_StatTabEntry *tabentry; /* table entry of shared stats */
PgStat_StatDBEntry *dbentry; /* pending database entry */
+ Assert(!anytime_only);
+
dboid = entry_ref->shared_entry->key.dboid;
lstats = (PgStat_TableStatus *) entry_ref->pending;
shtabstats = (PgStatShared_Relation *) entry_ref->shared_stats;
diff --git a/src/backend/utils/activity/pgstat_slru.c b/src/backend/utils/activity/pgstat_slru.c
index 2190f388eae..bf8a4d58673 100644
--- a/src/backend/utils/activity/pgstat_slru.c
+++ b/src/backend/utils/activity/pgstat_slru.c
@@ -19,6 +19,7 @@
#include "utils/pgstat_internal.h"
#include "utils/timestamp.h"
+#include "utils/timeout.h"
static inline PgStat_SLRUStats *get_slru_entry(int slru_idx);
@@ -139,7 +140,7 @@ pgstat_get_slru_index(const char *name)
* acquired. Otherwise return false.
*/
bool
-pgstat_slru_flush_cb(bool nowait)
+pgstat_slru_flush_cb(bool nowait, bool anytime_only)
{
PgStatShared_SLRU *stats_shmem = &pgStatLocal.shmem->slru;
int i;
@@ -223,6 +224,9 @@ get_slru_entry(int slru_idx)
Assert((slru_idx >= 0) && (slru_idx < SLRU_NUM_ELEMENTS));
+ /* Schedule next anytime stats update timeout */
+ pgstat_schedule_anytime_update();
+
have_slrustats = true;
pgstat_report_fixed = true;
diff --git a/src/backend/utils/activity/pgstat_subscription.c b/src/backend/utils/activity/pgstat_subscription.c
index 3277cf88a4e..6b6eec7578d 100644
--- a/src/backend/utils/activity/pgstat_subscription.c
+++ b/src/backend/utils/activity/pgstat_subscription.c
@@ -117,11 +117,13 @@ pgstat_fetch_stat_subscription(Oid subid)
* false without flushing the entry. Otherwise returns true.
*/
bool
-pgstat_subscription_flush_cb(PgStat_EntryRef *entry_ref, bool nowait)
+pgstat_subscription_flush_cb(PgStat_EntryRef *entry_ref, bool nowait, bool anytime_only)
{
PgStat_BackendSubEntry *localent;
PgStatShared_Subscription *shsubent;
+ Assert(!anytime_only);
+
localent = (PgStat_BackendSubEntry *) entry_ref->pending;
shsubent = (PgStatShared_Subscription *) entry_ref->shared_stats;
diff --git a/src/backend/utils/activity/pgstat_wal.c b/src/backend/utils/activity/pgstat_wal.c
index 183e0a7a97b..2c2f3f10e10 100644
--- a/src/backend/utils/activity/pgstat_wal.c
+++ b/src/backend/utils/activity/pgstat_wal.c
@@ -51,12 +51,12 @@ pgstat_report_wal(bool force)
nowait = !force;
/* flush wal stats */
- (void) pgstat_wal_flush_cb(nowait);
- pgstat_flush_backend(nowait, PGSTAT_BACKEND_FLUSH_WAL);
+ (void) pgstat_wal_flush_cb(nowait, true);
+ (void) pgstat_flush_backend(nowait, PGSTAT_BACKEND_FLUSH_WAL, true);
/* flush IO stats */
- pgstat_flush_io(nowait);
- (void) pgstat_flush_backend(nowait, PGSTAT_BACKEND_FLUSH_IO);
+ pgstat_flush_io(nowait, true);
+ (void) pgstat_flush_backend(nowait, PGSTAT_BACKEND_FLUSH_IO, true);
}
/*
@@ -88,7 +88,7 @@ pgstat_wal_have_pending(void)
* acquired. Otherwise return false.
*/
bool
-pgstat_wal_flush_cb(bool nowait)
+pgstat_wal_flush_cb(bool nowait, bool anytime_only)
{
PgStatShared_Wal *stats_shmem = &pgStatLocal.shmem->wal;
WalUsage wal_usage_diff = {0};
diff --git a/src/backend/utils/init/globals.c b/src/backend/utils/init/globals.c
index 36ad708b360..ad44826c39e 100644
--- a/src/backend/utils/init/globals.c
+++ b/src/backend/utils/init/globals.c
@@ -40,6 +40,7 @@ volatile sig_atomic_t IdleSessionTimeoutPending = false;
volatile sig_atomic_t ProcSignalBarrierPending = false;
volatile sig_atomic_t LogMemoryContextPending = false;
volatile sig_atomic_t IdleStatsUpdateTimeoutPending = false;
+volatile sig_atomic_t AnytimeStatsUpdateTimeoutPending = false;
volatile uint32 InterruptHoldoffCount = 0;
volatile uint32 QueryCancelHoldoffCount = 0;
volatile uint32 CritSectionCount = 0;
diff --git a/src/backend/utils/init/postinit.c b/src/backend/utils/init/postinit.c
index b59e08605cc..eeeac1bf39a 100644
--- a/src/backend/utils/init/postinit.c
+++ b/src/backend/utils/init/postinit.c
@@ -64,6 +64,7 @@
#include "utils/injection_point.h"
#include "utils/memutils.h"
#include "utils/pg_locale.h"
+#include "utils/pgstat_internal.h"
#include "utils/portal.h"
#include "utils/ps_status.h"
#include "utils/snapmgr.h"
@@ -773,6 +774,8 @@ InitPostgres(const char *in_dbname, Oid dboid,
RegisterTimeout(CLIENT_CONNECTION_CHECK_TIMEOUT, ClientCheckTimeoutHandler);
RegisterTimeout(IDLE_STATS_UPDATE_TIMEOUT,
IdleStatsUpdateTimeoutHandler);
+ RegisterTimeout(ANYTIME_STATS_UPDATE_TIMEOUT,
+ AnytimeStatsUpdateTimeoutHandler);
}
/*
diff --git a/src/include/miscadmin.h b/src/include/miscadmin.h
index f16f35659b9..84e698da214 100644
--- a/src/include/miscadmin.h
+++ b/src/include/miscadmin.h
@@ -96,6 +96,7 @@ extern PGDLLIMPORT volatile sig_atomic_t IdleSessionTimeoutPending;
extern PGDLLIMPORT volatile sig_atomic_t ProcSignalBarrierPending;
extern PGDLLIMPORT volatile sig_atomic_t LogMemoryContextPending;
extern PGDLLIMPORT volatile sig_atomic_t IdleStatsUpdateTimeoutPending;
+extern PGDLLIMPORT volatile sig_atomic_t AnytimeStatsUpdateTimeoutPending;
extern PGDLLIMPORT volatile sig_atomic_t CheckClientConnectionPending;
extern PGDLLIMPORT volatile sig_atomic_t ClientConnectionLost;
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9bb777c3d5a..b011a315679 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -34,6 +34,9 @@
/* Default directory to store temporary statistics data in */
#define PG_STAT_TMP_DIR "pg_stat_tmp"
+/* Minimum interval non-forced stats flushes */
+#define PGSTAT_MIN_INTERVAL 1000
+
/* Values for track_functions GUC variable --- order is significant! */
typedef enum TrackFunctionsLevel
{
@@ -532,8 +535,24 @@ extern void pgstat_initialize(void);
/* Functions called from backends */
extern long pgstat_report_stat(bool force);
+extern void pgstat_report_anytime_stat(bool force);
extern void pgstat_force_next_flush(void);
+/*
+ * Schedule the next anytime stats update timeout.
+ *
+ * This should be called whenever accumulating statistics that support
+ * FLUSH_ANYTIME flushing mode.
+ */
+#define pgstat_schedule_anytime_update() \
+ do { \
+ if (IsUnderPostmaster && !pgstat_pending_anytime) \
+ { \
+ enable_timeout_after(ANYTIME_STATS_UPDATE_TIMEOUT, PGSTAT_MIN_INTERVAL); \
+ pgstat_pending_anytime = true; \
+ } \
+ } while (0)
+
extern void pgstat_reset_counters(void);
extern void pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid);
extern void pgstat_reset_of_kind(PgStat_Kind kind);
@@ -806,6 +825,8 @@ extern PgStat_WalStats *pgstat_fetch_stat_wal(void);
* Variables in pgstat.c
*/
+extern PGDLLIMPORT bool pgstat_pending_anytime;
+
/* GUC parameters */
extern PGDLLIMPORT bool pgstat_track_counts;
extern PGDLLIMPORT int pgstat_track_functions;
@@ -849,4 +870,5 @@ extern PGDLLIMPORT PgStat_Counter pgStatTransactionIdleTime;
/* updated by the traffic cop and in errfinish() */
extern PGDLLIMPORT SessionEndType pgStatSessionEndCause;
+
#endif /* PGSTAT_H */
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 9b8fbae00ed..607f4255268 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -224,6 +224,19 @@ typedef struct PgStat_SubXactStatus
PgStat_TableXactStatus *first; /* head of list for this subxact */
} PgStat_SubXactStatus;
+/*
+ * Flush mode for statistics kinds.
+ *
+ * FLUSH_AT_TXN_BOUNDARY has to be the first because we want it to be the
+ * default value.
+ */
+typedef enum PgStat_FlushMode
+{
+ FLUSH_AT_TXN_BOUNDARY, /* All fields can only be flushed at
+ * transaction boundary */
+ FLUSH_ANYTIME, /* All fields can be flushed anytime,
+ * including within transactions */
+} PgStat_FlushMode;
/*
* Metadata for a specific kind of statistics.
@@ -251,6 +264,16 @@ typedef struct PgStat_KindInfo
*/
bool track_entry_count:1;
+ /*
+ * The mode of when to flush stats. See PgStat_FlushMode for more details.
+ *
+ * This member only has meaning for statistics kinds that accumulate
+ * pending stats and use flush callbacks. For kinds that write directly to
+ * shared memory (e.g., archiver, bgwriter, checkpointer), this member has
+ * no effect.
+ */
+ PgStat_FlushMode flush_mode;
+
/*
* The size of an entry in the shared stats hash table (pointed to by
* PgStatShared_HashEntry->body). For fixed-numbered statistics, this is
@@ -297,8 +320,10 @@ typedef struct PgStat_KindInfo
* For variable-numbered stats: flush pending stats. Required if pending
* data is used. See flush_static_cb when dealing with stats data that
* that cannot use PgStat_EntryRef->pending.
+ *
+ * The anytime_only parameter indicates whether this is an anytime flush.
*/
- bool (*flush_pending_cb) (PgStat_EntryRef *sr, bool nowait);
+ bool (*flush_pending_cb) (PgStat_EntryRef *sr, bool nowait, bool anytime_only);
/*
* For variable-numbered stats: delete pending stats. Optional.
@@ -366,8 +391,10 @@ typedef struct PgStat_KindInfo
*
* "pgstat_report_fixed" needs to be set to trigger the flush of pending
* stats.
+ *
+ * The anytime_only parameter indicates whether this is an anytime flush.
*/
- bool (*flush_static_cb) (bool nowait);
+ bool (*flush_static_cb) (bool nowait, bool anytime_only);
/*
* For fixed-numbered statistics: Reset All.
@@ -677,6 +704,7 @@ extern PgStat_EntryRef *pgstat_fetch_pending_entry(PgStat_Kind kind,
extern void *pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid);
extern void pgstat_snapshot_fixed(PgStat_Kind kind);
+extern void AnytimeStatsUpdateTimeoutHandler(void);
/*
@@ -696,8 +724,8 @@ extern void pgstat_archiver_snapshot_cb(void);
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
-extern bool pgstat_flush_backend(bool nowait, bits32 flags);
-extern bool pgstat_backend_flush_cb(bool nowait);
+extern bool pgstat_flush_backend(bool nowait, bits32 flags, bool anytime_only);
+extern bool pgstat_backend_flush_cb(bool nowait, bool anytime_only);
extern void pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header,
TimestampTz ts);
@@ -729,7 +757,7 @@ extern void AtEOXact_PgStat_Database(bool isCommit, bool parallel);
extern PgStat_StatDBEntry *pgstat_prep_database_pending(Oid dboid);
extern void pgstat_reset_database_timestamp(Oid dboid, TimestampTz ts);
-extern bool pgstat_database_flush_cb(PgStat_EntryRef *entry_ref, bool nowait);
+extern bool pgstat_database_flush_cb(PgStat_EntryRef *entry_ref, bool nowait, bool anytime_only);
extern void pgstat_database_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts);
@@ -737,7 +765,7 @@ extern void pgstat_database_reset_timestamp_cb(PgStatShared_Common *header, Time
* Functions in pgstat_function.c
*/
-extern bool pgstat_function_flush_cb(PgStat_EntryRef *entry_ref, bool nowait);
+extern bool pgstat_function_flush_cb(PgStat_EntryRef *entry_ref, bool nowait, bool anytime_only);
extern void pgstat_function_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts);
@@ -745,9 +773,9 @@ extern void pgstat_function_reset_timestamp_cb(PgStatShared_Common *header, Time
* Functions in pgstat_io.c
*/
-extern void pgstat_flush_io(bool nowait);
+extern void pgstat_flush_io(bool nowait, bool anytime_only);
-extern bool pgstat_io_flush_cb(bool nowait);
+extern bool pgstat_io_flush_cb(bool nowait, bool anytime_only);
extern void pgstat_io_init_shmem_cb(void *stats);
extern void pgstat_io_reset_all_cb(TimestampTz ts);
extern void pgstat_io_snapshot_cb(void);
@@ -762,7 +790,7 @@ extern void AtEOSubXact_PgStat_Relations(PgStat_SubXactStatus *xact_state, bool
extern void AtPrepare_PgStat_Relations(PgStat_SubXactStatus *xact_state);
extern void PostPrepare_PgStat_Relations(PgStat_SubXactStatus *xact_state);
-extern bool pgstat_relation_flush_cb(PgStat_EntryRef *entry_ref, bool nowait);
+extern bool pgstat_relation_flush_cb(PgStat_EntryRef *entry_ref, bool nowait, bool anytime_only);
extern void pgstat_relation_delete_pending_cb(PgStat_EntryRef *entry_ref);
extern void pgstat_relation_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts);
@@ -809,7 +837,7 @@ extern PgStatShared_Common *pgstat_init_entry(PgStat_Kind kind,
* Functions in pgstat_slru.c
*/
-extern bool pgstat_slru_flush_cb(bool nowait);
+extern bool pgstat_slru_flush_cb(bool nowait, bool anytime_only);
extern void pgstat_slru_init_shmem_cb(void *stats);
extern void pgstat_slru_reset_all_cb(TimestampTz ts);
extern void pgstat_slru_snapshot_cb(void);
@@ -820,7 +848,7 @@ extern void pgstat_slru_snapshot_cb(void);
*/
extern void pgstat_wal_init_backend_cb(void);
-extern bool pgstat_wal_flush_cb(bool nowait);
+extern bool pgstat_wal_flush_cb(bool nowait, bool anytime_only);
extern void pgstat_wal_init_shmem_cb(void *stats);
extern void pgstat_wal_reset_all_cb(TimestampTz ts);
extern void pgstat_wal_snapshot_cb(void);
@@ -830,7 +858,7 @@ extern void pgstat_wal_snapshot_cb(void);
* Functions in pgstat_subscription.c
*/
-extern bool pgstat_subscription_flush_cb(PgStat_EntryRef *entry_ref, bool nowait);
+extern bool pgstat_subscription_flush_cb(PgStat_EntryRef *entry_ref, bool nowait, bool anytime_only);
extern void pgstat_subscription_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts);
diff --git a/src/include/utils/timeout.h b/src/include/utils/timeout.h
index 0965b590b34..10723bb664c 100644
--- a/src/include/utils/timeout.h
+++ b/src/include/utils/timeout.h
@@ -35,6 +35,7 @@ typedef enum TimeoutId
IDLE_SESSION_TIMEOUT,
IDLE_STATS_UPDATE_TIMEOUT,
CLIENT_CONNECTION_CHECK_TIMEOUT,
+ ANYTIME_STATS_UPDATE_TIMEOUT,
STARTUP_PROGRESS_TIMEOUT,
/* First user-definable timeout reason */
USER_TIMEOUT,
diff --git a/src/test/modules/test_custom_stats/test_custom_var_stats.c b/src/test/modules/test_custom_stats/test_custom_var_stats.c
index da28afbd929..4c207611236 100644
--- a/src/test/modules/test_custom_stats/test_custom_var_stats.c
+++ b/src/test/modules/test_custom_stats/test_custom_var_stats.c
@@ -84,7 +84,7 @@ static dsa_area *custom_stats_description_dsa = NULL;
/* Flush callback: merge pending stats into shared memory */
static bool test_custom_stats_var_flush_pending_cb(PgStat_EntryRef *entry_ref,
- bool nowait);
+ bool nowait, bool anytime_only);
/* Serialization callback: write auxiliary entry data */
static void test_custom_stats_var_to_serialized_data(const PgStat_HashKey *key,
@@ -151,7 +151,7 @@ _PG_init(void)
* Returns false only if nowait=true and lock acquisition fails.
*/
static bool
-test_custom_stats_var_flush_pending_cb(PgStat_EntryRef *entry_ref, bool nowait)
+test_custom_stats_var_flush_pending_cb(PgStat_EntryRef *entry_ref, bool nowait, bool anytime_only)
{
PgStat_StatCustomVarEntry *pending_entry;
PgStatShared_CustomVarEntry *shared_entry;
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 241945734ec..1dbc4b96f51 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -2271,6 +2271,7 @@ PgStat_Counter
PgStat_EntryRef
PgStat_EntryRefHashEntry
PgStat_FetchConsistency
+PgStat_FlushMode
PgStat_FunctionCallUsage
PgStat_FunctionCounts
PgStat_HashKey
--
2.34.1
--NVvBxFuyV/R+1/8/
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v10-0002-Add-anytime-flush-tests-for-custom-stats.patch"
^ permalink raw reply [nested|flat] 12+ messages in thread
* [PATCH v11 1/5] Add pgstat_report_anytime_stat() for periodic stats flushing
@ 2026-01-05 09:41 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 12+ messages in thread
From: Bertrand Drouvot @ 2026-01-05 09:41 UTC (permalink / raw)
Long running transactions can accumulate significant statistics (WAL, IO, ...)
that remain unflushed until the transaction ends. This delays visibility of
resource usage in monitoring views like pg_stat_io and pg_stat_wal and produces
spikes when flushed.
This commit introduces pgstat_report_anytime_stat(), which flushes
non transactional statistics even inside active transactions. A new timeout
handler fires every second (if enabled while adding pending stats) to call this
function, ensuring timely stats visibility without waiting for transaction completion.
Implementation details:
- Add PgStat_FlushMode enum to classify stats kinds:
* FLUSH_ANYTIME: Stats that can always be flushed (WAL, IO, ...)
* FLUSH_AT_TXN_BOUNDARY: Stats requiring transaction boundaries
- Modify pgstat_flush_pending_entries() and pgstat_flush_fixed_stats()
to accept a boolean anytime_only parameter:
* When false: flushes all stats (existing behavior)
* When true: flushes only FLUSH_ANYTIME stats and skips FLUSH_AT_TXN_BOUNDARY stats
- The flush_pending_cb and flush_static_cb callbacks now receive an anytime_only
boolean parameter. Most of the time it's not used (except for assertions), but it's
preparatory work for moving the relations stats to anytime (without introducin
a new callback).
- Add pgstat_schedule_anytime_update() macro to schedule the next anytime flush,
relying on PGSTAT_MIN_INTERVAL
The force parameter in pgstat_report_anytime_stat() is currently unused (always
called with force=false) but reserved for future use cases requiring immediate
flushing.
---
src/backend/access/transam/xlog.c | 6 +
src/backend/postmaster/bgwriter.c | 9 +-
src/backend/postmaster/checkpointer.c | 10 +-
src/backend/postmaster/startup.c | 2 +
src/backend/postmaster/walsummarizer.c | 9 +-
src/backend/postmaster/walwriter.c | 9 +-
src/backend/replication/walreceiver.c | 9 +-
src/backend/replication/walsender.c | 8 +-
src/backend/tcop/postgres.c | 12 ++
src/backend/utils/activity/pgstat.c | 121 +++++++++++++++---
src/backend/utils/activity/pgstat_backend.c | 13 +-
src/backend/utils/activity/pgstat_bgwriter.c | 2 +-
.../utils/activity/pgstat_checkpointer.c | 2 +-
src/backend/utils/activity/pgstat_database.c | 2 +-
src/backend/utils/activity/pgstat_function.c | 4 +-
src/backend/utils/activity/pgstat_io.c | 10 +-
src/backend/utils/activity/pgstat_relation.c | 12 +-
src/backend/utils/activity/pgstat_slru.c | 6 +-
.../utils/activity/pgstat_subscription.c | 4 +-
src/backend/utils/activity/pgstat_wal.c | 10 +-
src/backend/utils/init/globals.c | 1 +
src/backend/utils/init/postinit.c | 3 +
src/include/miscadmin.h | 1 +
src/include/pgstat.h | 22 ++++
src/include/utils/pgstat_internal.h | 52 ++++++--
src/include/utils/timeout.h | 1 +
.../test_custom_stats/test_custom_var_stats.c | 4 +-
src/tools/pgindent/typedefs.list | 1 +
28 files changed, 279 insertions(+), 66 deletions(-)
10.5% src/backend/postmaster/
5.8% src/backend/replication/
51.0% src/backend/utils/activity/
5.8% src/backend/
18.7% src/include/utils/
6.6% src/include/
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 13cce9b49f1..cf29fc91f70 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -1085,6 +1085,9 @@ XLogInsertRecord(XLogRecData *rdata,
pgWalUsage.wal_fpi += num_fpi;
pgWalUsage.wal_fpi_bytes += fpi_bytes;
+ /* Schedule next anytime stats update timeout */
+ pgstat_schedule_anytime_update();
+
/* Required for the flush of pending stats WAL data */
pgstat_report_fixed = true;
}
@@ -2066,6 +2069,9 @@ AdvanceXLInsertBuffer(XLogRecPtr upto, TimeLineID tli, bool opportunistic)
pgWalUsage.wal_buffers_full++;
TRACE_POSTGRESQL_WAL_BUFFER_WRITE_DIRTY_DONE();
+ /* Schedule next anytime stats update timeout */
+ pgstat_schedule_anytime_update();
+
/*
* Required for the flush of pending stats WAL data, per
* update of pgWalUsage.
diff --git a/src/backend/postmaster/bgwriter.c b/src/backend/postmaster/bgwriter.c
index 0956bd39a85..059c601c3b8 100644
--- a/src/backend/postmaster/bgwriter.c
+++ b/src/backend/postmaster/bgwriter.c
@@ -49,7 +49,9 @@
#include "storage/smgr.h"
#include "storage/standby.h"
#include "utils/memutils.h"
+#include "utils/pgstat_internal.h"
#include "utils/resowner.h"
+#include "utils/timeout.h"
#include "utils/timestamp.h"
/*
@@ -103,7 +105,7 @@ BackgroundWriterMain(const void *startup_data, size_t startup_data_len)
pqsignal(SIGINT, SIG_IGN);
pqsignal(SIGTERM, SignalHandlerForShutdownRequest);
/* SIGQUIT handler was already set up by InitPostmasterChild */
- pqsignal(SIGALRM, SIG_IGN);
+ InitializeTimeouts(); /* establishes SIGALRM handler */
pqsignal(SIGPIPE, SIG_IGN);
pqsignal(SIGUSR1, procsignal_sigusr1_handler);
pqsignal(SIGUSR2, SIG_IGN);
@@ -113,6 +115,11 @@ BackgroundWriterMain(const void *startup_data, size_t startup_data_len)
*/
pqsignal(SIGCHLD, SIG_DFL);
+ /*
+ * Register timeouts needed
+ */
+ RegisterTimeout(ANYTIME_STATS_UPDATE_TIMEOUT, AnytimeStatsUpdateTimeoutHandler);
+
/*
* We just started, assume there has been either a shutdown or
* end-of-recovery snapshot.
diff --git a/src/backend/postmaster/checkpointer.c b/src/backend/postmaster/checkpointer.c
index e03c19123bc..e11c4b099c8 100644
--- a/src/backend/postmaster/checkpointer.c
+++ b/src/backend/postmaster/checkpointer.c
@@ -66,8 +66,9 @@
#include "utils/acl.h"
#include "utils/guc.h"
#include "utils/memutils.h"
+#include "utils/pgstat_internal.h"
#include "utils/resowner.h"
-
+#include "utils/timeout.h"
/*----------
* Shared memory area for communication between checkpointer and backends
@@ -215,7 +216,7 @@ CheckpointerMain(const void *startup_data, size_t startup_data_len)
pqsignal(SIGINT, ReqShutdownXLOG);
pqsignal(SIGTERM, SIG_IGN); /* ignore SIGTERM */
/* SIGQUIT handler was already set up by InitPostmasterChild */
- pqsignal(SIGALRM, SIG_IGN);
+ InitializeTimeouts(); /* establishes SIGALRM handler */
pqsignal(SIGPIPE, SIG_IGN);
pqsignal(SIGUSR1, procsignal_sigusr1_handler);
pqsignal(SIGUSR2, SignalHandlerForShutdownRequest);
@@ -225,6 +226,11 @@ CheckpointerMain(const void *startup_data, size_t startup_data_len)
*/
pqsignal(SIGCHLD, SIG_DFL);
+ /*
+ * Register timeouts needed
+ */
+ RegisterTimeout(ANYTIME_STATS_UPDATE_TIMEOUT, AnytimeStatsUpdateTimeoutHandler);
+
/*
* Initialize so that first time-driven event happens at the correct time.
*/
diff --git a/src/backend/postmaster/startup.c b/src/backend/postmaster/startup.c
index cdbe53dd262..4954fe425b7 100644
--- a/src/backend/postmaster/startup.c
+++ b/src/backend/postmaster/startup.c
@@ -32,6 +32,7 @@
#include "storage/standby.h"
#include "utils/guc.h"
#include "utils/memutils.h"
+#include "utils/pgstat_internal.h"
#include "utils/timeout.h"
@@ -245,6 +246,7 @@ StartupProcessMain(const void *startup_data, size_t startup_data_len)
RegisterTimeout(STANDBY_DEADLOCK_TIMEOUT, StandbyDeadLockHandler);
RegisterTimeout(STANDBY_TIMEOUT, StandbyTimeoutHandler);
RegisterTimeout(STANDBY_LOCK_TIMEOUT, StandbyLockTimeoutHandler);
+ RegisterTimeout(ANYTIME_STATS_UPDATE_TIMEOUT, AnytimeStatsUpdateTimeoutHandler);
/*
* Unblock signals (they were blocked when the postmaster forked us)
diff --git a/src/backend/postmaster/walsummarizer.c b/src/backend/postmaster/walsummarizer.c
index 742137edad6..f1bae9d23d6 100644
--- a/src/backend/postmaster/walsummarizer.c
+++ b/src/backend/postmaster/walsummarizer.c
@@ -48,6 +48,8 @@
#include "storage/shmem.h"
#include "utils/guc.h"
#include "utils/memutils.h"
+#include "utils/pgstat_internal.h"
+#include "utils/timeout.h"
#include "utils/wait_event.h"
/*
@@ -246,7 +248,7 @@ WalSummarizerMain(const void *startup_data, size_t startup_data_len)
pqsignal(SIGINT, SIG_IGN); /* no query to cancel */
pqsignal(SIGTERM, SignalHandlerForShutdownRequest);
/* SIGQUIT handler was already set up by InitPostmasterChild */
- pqsignal(SIGALRM, SIG_IGN);
+ InitializeTimeouts(); /* establishes SIGALRM handler */
pqsignal(SIGPIPE, SIG_IGN);
pqsignal(SIGUSR1, procsignal_sigusr1_handler);
pqsignal(SIGUSR2, SIG_IGN); /* not used */
@@ -268,6 +270,11 @@ WalSummarizerMain(const void *startup_data, size_t startup_data_len)
*/
pqsignal(SIGCHLD, SIG_DFL);
+ /*
+ * Register timeouts needed
+ */
+ RegisterTimeout(ANYTIME_STATS_UPDATE_TIMEOUT, AnytimeStatsUpdateTimeoutHandler);
+
/*
* If an exception is encountered, processing resumes here.
*/
diff --git a/src/backend/postmaster/walwriter.c b/src/backend/postmaster/walwriter.c
index 7c0e2809c17..bcf59227a00 100644
--- a/src/backend/postmaster/walwriter.c
+++ b/src/backend/postmaster/walwriter.c
@@ -61,7 +61,9 @@
#include "storage/smgr.h"
#include "utils/hsearch.h"
#include "utils/memutils.h"
+#include "utils/pgstat_internal.h"
#include "utils/resowner.h"
+#include "utils/timeout.h"
/*
@@ -103,7 +105,7 @@ WalWriterMain(const void *startup_data, size_t startup_data_len)
pqsignal(SIGINT, SIG_IGN); /* no query to cancel */
pqsignal(SIGTERM, SignalHandlerForShutdownRequest);
/* SIGQUIT handler was already set up by InitPostmasterChild */
- pqsignal(SIGALRM, SIG_IGN);
+ InitializeTimeouts(); /* establishes SIGALRM handler */
pqsignal(SIGPIPE, SIG_IGN);
pqsignal(SIGUSR1, procsignal_sigusr1_handler);
pqsignal(SIGUSR2, SIG_IGN); /* not used */
@@ -113,6 +115,11 @@ WalWriterMain(const void *startup_data, size_t startup_data_len)
*/
pqsignal(SIGCHLD, SIG_DFL);
+ /*
+ * Register timeouts needed
+ */
+ RegisterTimeout(ANYTIME_STATS_UPDATE_TIMEOUT, AnytimeStatsUpdateTimeoutHandler);
+
/*
* Create a memory context that we will do all our work in. We do this so
* that we can reset the context during error recovery and thereby avoid
diff --git a/src/backend/replication/walreceiver.c b/src/backend/replication/walreceiver.c
index 7c1b8757d7d..aecc7a127e6 100644
--- a/src/backend/replication/walreceiver.c
+++ b/src/backend/replication/walreceiver.c
@@ -77,7 +77,9 @@
#include "utils/builtins.h"
#include "utils/guc.h"
#include "utils/pg_lsn.h"
+#include "utils/pgstat_internal.h"
#include "utils/ps_status.h"
+#include "utils/timeout.h"
#include "utils/timestamp.h"
@@ -252,7 +254,7 @@ WalReceiverMain(const void *startup_data, size_t startup_data_len)
pqsignal(SIGINT, SIG_IGN);
pqsignal(SIGTERM, die); /* request shutdown */
/* SIGQUIT handler was already set up by InitPostmasterChild */
- pqsignal(SIGALRM, SIG_IGN);
+ InitializeTimeouts(); /* establishes SIGALRM handler */
pqsignal(SIGPIPE, SIG_IGN);
pqsignal(SIGUSR1, procsignal_sigusr1_handler);
pqsignal(SIGUSR2, SIG_IGN);
@@ -260,6 +262,11 @@ WalReceiverMain(const void *startup_data, size_t startup_data_len)
/* Reset some signals that are accepted by postmaster but not here */
pqsignal(SIGCHLD, SIG_DFL);
+ /*
+ * Register timeouts needed
+ */
+ RegisterTimeout(ANYTIME_STATS_UPDATE_TIMEOUT, AnytimeStatsUpdateTimeoutHandler);
+
/* Load the libpq-specific functions */
load_file("libpqwalreceiver", false);
if (WalReceiverFunctions == NULL)
diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c
index 2cde8ebc729..a7214d0dc6f 100644
--- a/src/backend/replication/walsender.c
+++ b/src/backend/replication/walsender.c
@@ -1987,8 +1987,8 @@ WalSndWaitForWal(XLogRecPtr loc)
if (TimestampDifferenceExceeds(last_flush, now,
WALSENDER_STATS_FLUSH_INTERVAL))
{
- pgstat_flush_io(false);
- (void) pgstat_flush_backend(false, PGSTAT_BACKEND_FLUSH_IO);
+ pgstat_flush_io(false, true);
+ (void) pgstat_flush_backend(false, PGSTAT_BACKEND_FLUSH_IO, true);
last_flush = now;
}
@@ -3016,8 +3016,8 @@ WalSndLoop(WalSndSendDataCallback send_data)
if (TimestampDifferenceExceeds(last_flush, now,
WALSENDER_STATS_FLUSH_INTERVAL))
{
- pgstat_flush_io(false);
- (void) pgstat_flush_backend(false, PGSTAT_BACKEND_FLUSH_IO);
+ pgstat_flush_io(false, true);
+ (void) pgstat_flush_backend(false, PGSTAT_BACKEND_FLUSH_IO, true);
last_flush = now;
}
diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c
index d01a09dd0c4..8c30efa2443 100644
--- a/src/backend/tcop/postgres.c
+++ b/src/backend/tcop/postgres.c
@@ -3564,6 +3564,18 @@ ProcessInterrupts(void)
pgstat_report_stat(true);
}
+ /*
+ * Flush stats outside of transaction boundary if the timeout fired.
+ * Unlike transactional stats, these can be flushed even inside a running
+ * transaction.
+ */
+ if (AnytimeStatsUpdateTimeoutPending)
+ {
+ AnytimeStatsUpdateTimeoutPending = false;
+
+ pgstat_report_anytime_stat(false);
+ }
+
if (ProcSignalBarrierPending)
ProcessProcSignalBarrier();
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index 11bb71cad5a..ddd331e2c81 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -108,10 +108,12 @@
#include "pgstat.h"
#include "storage/fd.h"
#include "storage/ipc.h"
+#include "storage/latch.h"
#include "storage/lwlock.h"
#include "utils/guc_hooks.h"
#include "utils/memutils.h"
#include "utils/pgstat_internal.h"
+#include "utils/timeout.h"
#include "utils/timestamp.h"
@@ -122,8 +124,6 @@
* ----------
*/
-/* minimum interval non-forced stats flushes.*/
-#define PGSTAT_MIN_INTERVAL 1000
/* how long until to block flushing pending stats updates */
#define PGSTAT_MAX_INTERVAL 60000
/* when to call pgstat_report_stat() again, even when idle */
@@ -187,7 +187,8 @@ static void pgstat_init_snapshot_fixed(void);
static void pgstat_reset_after_failure(void);
-static bool pgstat_flush_pending_entries(bool nowait);
+static bool pgstat_flush_pending_entries(bool nowait, bool anytime_only);
+static bool pgstat_flush_fixed_stats(bool nowait, bool anytime_only);
static void pgstat_prep_snapshot(void);
static void pgstat_build_snapshot(void);
@@ -218,6 +219,12 @@ PgStat_LocalState pgStatLocal;
*/
bool pgstat_report_fixed = false;
+/*
+ * Track when there is pending anytime flush to avoid relying on
+ * get_timeout_active() in hot pathes.
+ */
+bool pgstat_pending_anytime = false;
+
/* ----------
* Local data
*
@@ -288,6 +295,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = true,
+ .flush_mode = FLUSH_AT_TXN_BOUNDARY,
/* so pg_stat_database entries can be seen in all databases */
.accessed_across_databases = true,
@@ -305,6 +313,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = true,
+ .flush_mode = FLUSH_AT_TXN_BOUNDARY,
.shared_size = sizeof(PgStatShared_Relation),
.shared_data_off = offsetof(PgStatShared_Relation, stats),
@@ -321,6 +330,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = true,
+ .flush_mode = FLUSH_AT_TXN_BOUNDARY,
.shared_size = sizeof(PgStatShared_Function),
.shared_data_off = offsetof(PgStatShared_Function, stats),
@@ -336,6 +346,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = true,
+ .flush_mode = FLUSH_AT_TXN_BOUNDARY,
.accessed_across_databases = true,
@@ -353,6 +364,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = true,
+ .flush_mode = FLUSH_AT_TXN_BOUNDARY,
/* so pg_stat_subscription_stats entries can be seen in all databases */
.accessed_across_databases = true,
@@ -370,6 +382,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = false,
+ .flush_mode = FLUSH_ANYTIME,
.accessed_across_databases = true,
@@ -436,6 +449,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = true,
.write_to_file = true,
+ .flush_mode = FLUSH_ANYTIME,
.snapshot_ctl_off = offsetof(PgStat_Snapshot, io),
.shared_ctl_off = offsetof(PgStat_ShmemControl, io),
@@ -453,6 +467,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = true,
.write_to_file = true,
+ .flush_mode = FLUSH_ANYTIME,
.snapshot_ctl_off = offsetof(PgStat_Snapshot, slru),
.shared_ctl_off = offsetof(PgStat_ShmemControl, slru),
@@ -470,6 +485,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = true,
.write_to_file = true,
+ .flush_mode = FLUSH_ANYTIME,
.snapshot_ctl_off = offsetof(PgStat_Snapshot, wal),
.shared_ctl_off = offsetof(PgStat_ShmemControl, wal),
@@ -775,23 +791,11 @@ pgstat_report_stat(bool force)
partial_flush = false;
/* flush of variable-numbered stats tracked in pending entries list */
- partial_flush |= pgstat_flush_pending_entries(nowait);
+ partial_flush |= pgstat_flush_pending_entries(nowait, false);
/* flush of other stats kinds */
if (pgstat_report_fixed)
- {
- for (PgStat_Kind kind = PGSTAT_KIND_MIN; kind <= PGSTAT_KIND_MAX; kind++)
- {
- const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
-
- if (!kind_info)
- continue;
- if (!kind_info->flush_static_cb)
- continue;
-
- partial_flush |= kind_info->flush_static_cb(nowait);
- }
- }
+ partial_flush |= pgstat_flush_fixed_stats(nowait, false);
last_flush = now;
@@ -1293,7 +1297,8 @@ pgstat_prep_pending_entry(PgStat_Kind kind, Oid dboid, uint64 objid, bool *creat
if (entry_ref->pending == NULL)
{
- size_t entrysize = pgstat_get_kind_info(kind)->pending_size;
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+ size_t entrysize = kind_info->pending_size;
Assert(entrysize != (size_t) -1);
@@ -1345,9 +1350,14 @@ pgstat_delete_pending_entry(PgStat_EntryRef *entry_ref)
/*
* Flush out pending variable-numbered stats.
+ *
+ * If anytime_only is true, only flushes FLUSH_ANYTIME entries.
+ * This is safe to call inside transactions.
+ *
+ * If anytime_only is false, flushes all entries.
*/
static bool
-pgstat_flush_pending_entries(bool nowait)
+pgstat_flush_pending_entries(bool nowait, bool anytime_only)
{
bool have_pending = false;
dlist_node *cur = NULL;
@@ -1377,8 +1387,22 @@ pgstat_flush_pending_entries(bool nowait)
Assert(!kind_info->fixed_amount);
Assert(kind_info->flush_pending_cb != NULL);
+ /* Skip transactional stats if we're in anytime_only mode */
+ if (anytime_only && kind_info->flush_mode == FLUSH_AT_TXN_BOUNDARY)
+ {
+ have_pending = true;
+
+ if (dlist_has_next(&pgStatPending, cur))
+ next = dlist_next_node(&pgStatPending, cur);
+ else
+ next = NULL;
+
+ cur = next;
+ continue;
+ }
+
/* flush the stats, if possible */
- did_flush = kind_info->flush_pending_cb(entry_ref, nowait);
+ did_flush = kind_info->flush_pending_cb(entry_ref, nowait, anytime_only);
Assert(did_flush || nowait);
@@ -1402,6 +1426,33 @@ pgstat_flush_pending_entries(bool nowait)
return have_pending;
}
+/*
+ * Flush fixed-amount stats.
+ *
+ * If anytime_only is true, only flushes FLUSH_ANYTIME stats (safe inside transactions).
+ * If anytime_only is false, flushes all stats with flush_static_cb.
+ */
+static bool
+pgstat_flush_fixed_stats(bool nowait, bool anytime_only)
+{
+ bool partial_flush = false;
+
+ for (PgStat_Kind kind = PGSTAT_KIND_MIN; kind <= PGSTAT_KIND_MAX; kind++)
+ {
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (!kind_info || !kind_info->flush_static_cb)
+ continue;
+
+ /* Skip transactional stats if we're in anytime_only mode */
+ if (anytime_only && kind_info->flush_mode == FLUSH_AT_TXN_BOUNDARY)
+ continue;
+
+ partial_flush |= kind_info->flush_static_cb(nowait, anytime_only);
+ }
+
+ return partial_flush;
+}
/* ------------------------------------------------------------
* Helper / infrastructure functions
@@ -2119,3 +2170,33 @@ assign_stats_fetch_consistency(int newval, void *extra)
if (pgstat_fetch_consistency != newval)
force_stats_snapshot_clear = true;
}
+
+/*
+ * Flushes only FLUSH_ANYTIME stats using non-blocking locks. Transactional
+ * stats (FLUSH_AT_TXN_BOUNDARY) remain pending until transaction boundary.
+ * Safe to call inside transactions.
+ */
+void
+pgstat_report_anytime_stat(bool force)
+{
+ bool nowait = !force;
+
+ pgstat_assert_is_up();
+
+ /* Flush stats outside of transaction boundary */
+ pgstat_flush_pending_entries(nowait, true);
+ pgstat_flush_fixed_stats(nowait, true);
+
+ pgstat_pending_anytime = false;
+}
+
+/*
+ * Timeout handler for flushing anytime stats.
+ */
+void
+AnytimeStatsUpdateTimeoutHandler(void)
+{
+ AnytimeStatsUpdateTimeoutPending = true;
+ InterruptPending = true;
+ SetLatch(MyLatch);
+}
diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c
index f2f8d3ff75f..b09316d3ab3 100644
--- a/src/backend/utils/activity/pgstat_backend.c
+++ b/src/backend/utils/activity/pgstat_backend.c
@@ -31,6 +31,7 @@
#include "storage/procarray.h"
#include "utils/memutils.h"
#include "utils/pgstat_internal.h"
+#include "utils/timeout.h"
/*
* Backend statistics counts waiting to be flushed out. These counters may be
@@ -66,6 +67,9 @@ pgstat_count_backend_io_op_time(IOObject io_object, IOContext io_context,
INSTR_TIME_ADD(PendingBackendStats.pending_io.pending_times[io_object][io_context][io_op],
io_time);
+ /* Schedule next anytime stats update timeout */
+ pgstat_schedule_anytime_update();
+
backend_has_iostats = true;
pgstat_report_fixed = true;
}
@@ -82,6 +86,9 @@ pgstat_count_backend_io_op(IOObject io_object, IOContext io_context,
PendingBackendStats.pending_io.counts[io_object][io_context][io_op] += cnt;
PendingBackendStats.pending_io.bytes[io_object][io_context][io_op] += bytes;
+ /* Schedule next anytime stats update timeout */
+ pgstat_schedule_anytime_update();
+
backend_has_iostats = true;
pgstat_report_fixed = true;
}
@@ -268,7 +275,7 @@ pgstat_flush_backend_entry_wal(PgStat_EntryRef *entry_ref)
* if some statistics could not be flushed due to lock contention.
*/
bool
-pgstat_flush_backend(bool nowait, bits32 flags)
+pgstat_flush_backend(bool nowait, bits32 flags, bool anytime_only)
{
PgStat_EntryRef *entry_ref;
bool has_pending_data = false;
@@ -311,9 +318,9 @@ pgstat_flush_backend(bool nowait, bits32 flags)
* If some stats could not be flushed due to lock contention, return true.
*/
bool
-pgstat_backend_flush_cb(bool nowait)
+pgstat_backend_flush_cb(bool nowait, bool anytime_only)
{
- return pgstat_flush_backend(nowait, PGSTAT_BACKEND_FLUSH_ALL);
+ return pgstat_flush_backend(nowait, PGSTAT_BACKEND_FLUSH_ALL, anytime_only);
}
/*
diff --git a/src/backend/utils/activity/pgstat_bgwriter.c b/src/backend/utils/activity/pgstat_bgwriter.c
index ed2fd801189..1c5f0c3ec40 100644
--- a/src/backend/utils/activity/pgstat_bgwriter.c
+++ b/src/backend/utils/activity/pgstat_bgwriter.c
@@ -61,7 +61,7 @@ pgstat_report_bgwriter(void)
/*
* Report IO statistics
*/
- pgstat_flush_io(false);
+ pgstat_flush_io(false, true);
}
/*
diff --git a/src/backend/utils/activity/pgstat_checkpointer.c b/src/backend/utils/activity/pgstat_checkpointer.c
index 1f70194b7a7..2d89a082464 100644
--- a/src/backend/utils/activity/pgstat_checkpointer.c
+++ b/src/backend/utils/activity/pgstat_checkpointer.c
@@ -68,7 +68,7 @@ pgstat_report_checkpointer(void)
/*
* Report IO statistics
*/
- pgstat_flush_io(false);
+ pgstat_flush_io(false, true);
}
/*
diff --git a/src/backend/utils/activity/pgstat_database.c b/src/backend/utils/activity/pgstat_database.c
index 933dcb5cae5..8e86df60461 100644
--- a/src/backend/utils/activity/pgstat_database.c
+++ b/src/backend/utils/activity/pgstat_database.c
@@ -435,7 +435,7 @@ pgstat_reset_database_timestamp(Oid dboid, TimestampTz ts)
* false without flushing the entry. Otherwise returns true.
*/
bool
-pgstat_database_flush_cb(PgStat_EntryRef *entry_ref, bool nowait)
+pgstat_database_flush_cb(PgStat_EntryRef *entry_ref, bool nowait, bool anytime_only)
{
PgStatShared_Database *sharedent;
PgStat_StatDBEntry *pendingent;
diff --git a/src/backend/utils/activity/pgstat_function.c b/src/backend/utils/activity/pgstat_function.c
index e6b84283c6c..5ba4958382f 100644
--- a/src/backend/utils/activity/pgstat_function.c
+++ b/src/backend/utils/activity/pgstat_function.c
@@ -190,11 +190,13 @@ pgstat_end_function_usage(PgStat_FunctionCallUsage *fcu, bool finalize)
* false without flushing the entry. Otherwise returns true.
*/
bool
-pgstat_function_flush_cb(PgStat_EntryRef *entry_ref, bool nowait)
+pgstat_function_flush_cb(PgStat_EntryRef *entry_ref, bool nowait, bool anytime_only)
{
PgStat_FunctionCounts *localent;
PgStatShared_Function *shfuncent;
+ Assert(!anytime_only);
+
localent = (PgStat_FunctionCounts *) entry_ref->pending;
shfuncent = (PgStatShared_Function *) entry_ref->shared_stats;
diff --git a/src/backend/utils/activity/pgstat_io.c b/src/backend/utils/activity/pgstat_io.c
index 28de24538dc..7cd32900236 100644
--- a/src/backend/utils/activity/pgstat_io.c
+++ b/src/backend/utils/activity/pgstat_io.c
@@ -19,6 +19,7 @@
#include "executor/instrument.h"
#include "storage/bufmgr.h"
#include "utils/pgstat_internal.h"
+#include "utils/timeout.h"
static PgStat_PendingIO PendingIOStats;
static bool have_iostats = false;
@@ -79,6 +80,9 @@ pgstat_count_io_op(IOObject io_object, IOContext io_context, IOOp io_op,
/* Add the per-backend counts */
pgstat_count_backend_io_op(io_object, io_context, io_op, cnt, bytes);
+ /* Schedule next anytime stats update timeout */
+ pgstat_schedule_anytime_update();
+
have_iostats = true;
pgstat_report_fixed = true;
}
@@ -172,9 +176,9 @@ pgstat_fetch_stat_io(void)
* Simpler wrapper of pgstat_io_flush_cb()
*/
void
-pgstat_flush_io(bool nowait)
+pgstat_flush_io(bool nowait, bool anytime_only)
{
- (void) pgstat_io_flush_cb(nowait);
+ (void) pgstat_io_flush_cb(nowait, anytime_only);
}
/*
@@ -186,7 +190,7 @@ pgstat_flush_io(bool nowait)
* acquired. Otherwise, return false.
*/
bool
-pgstat_io_flush_cb(bool nowait)
+pgstat_io_flush_cb(bool nowait, bool anytime_only)
{
LWLock *bktype_lock;
PgStat_BktypeIO *bktype_shstats;
diff --git a/src/backend/utils/activity/pgstat_relation.c b/src/backend/utils/activity/pgstat_relation.c
index bc8c43b96aa..04d21483d93 100644
--- a/src/backend/utils/activity/pgstat_relation.c
+++ b/src/backend/utils/activity/pgstat_relation.c
@@ -267,8 +267,8 @@ pgstat_report_vacuum(Relation rel, PgStat_Counter livetuples,
* is done -- which will likely vacuum many relations -- or until the
* VACUUM command has processed all tables and committed.
*/
- pgstat_flush_io(false);
- (void) pgstat_flush_backend(false, PGSTAT_BACKEND_FLUSH_IO);
+ pgstat_flush_io(false, true);
+ (void) pgstat_flush_backend(false, PGSTAT_BACKEND_FLUSH_IO, true);
}
/*
@@ -362,8 +362,8 @@ pgstat_report_analyze(Relation rel,
pgstat_unlock_entry(entry_ref);
/* see pgstat_report_vacuum() */
- pgstat_flush_io(false);
- (void) pgstat_flush_backend(false, PGSTAT_BACKEND_FLUSH_IO);
+ pgstat_flush_io(false, true);
+ (void) pgstat_flush_backend(false, PGSTAT_BACKEND_FLUSH_IO, true);
}
/*
@@ -812,7 +812,7 @@ pgstat_twophase_postabort(FullTransactionId fxid, uint16 info,
* entry when successfully flushing.
*/
bool
-pgstat_relation_flush_cb(PgStat_EntryRef *entry_ref, bool nowait)
+pgstat_relation_flush_cb(PgStat_EntryRef *entry_ref, bool nowait, bool anytime_only)
{
Oid dboid;
PgStat_TableStatus *lstats; /* pending stats entry */
@@ -820,6 +820,8 @@ pgstat_relation_flush_cb(PgStat_EntryRef *entry_ref, bool nowait)
PgStat_StatTabEntry *tabentry; /* table entry of shared stats */
PgStat_StatDBEntry *dbentry; /* pending database entry */
+ Assert(!anytime_only);
+
dboid = entry_ref->shared_entry->key.dboid;
lstats = (PgStat_TableStatus *) entry_ref->pending;
shtabstats = (PgStatShared_Relation *) entry_ref->shared_stats;
diff --git a/src/backend/utils/activity/pgstat_slru.c b/src/backend/utils/activity/pgstat_slru.c
index 2190f388eae..bf8a4d58673 100644
--- a/src/backend/utils/activity/pgstat_slru.c
+++ b/src/backend/utils/activity/pgstat_slru.c
@@ -19,6 +19,7 @@
#include "utils/pgstat_internal.h"
#include "utils/timestamp.h"
+#include "utils/timeout.h"
static inline PgStat_SLRUStats *get_slru_entry(int slru_idx);
@@ -139,7 +140,7 @@ pgstat_get_slru_index(const char *name)
* acquired. Otherwise return false.
*/
bool
-pgstat_slru_flush_cb(bool nowait)
+pgstat_slru_flush_cb(bool nowait, bool anytime_only)
{
PgStatShared_SLRU *stats_shmem = &pgStatLocal.shmem->slru;
int i;
@@ -223,6 +224,9 @@ get_slru_entry(int slru_idx)
Assert((slru_idx >= 0) && (slru_idx < SLRU_NUM_ELEMENTS));
+ /* Schedule next anytime stats update timeout */
+ pgstat_schedule_anytime_update();
+
have_slrustats = true;
pgstat_report_fixed = true;
diff --git a/src/backend/utils/activity/pgstat_subscription.c b/src/backend/utils/activity/pgstat_subscription.c
index 3277cf88a4e..6b6eec7578d 100644
--- a/src/backend/utils/activity/pgstat_subscription.c
+++ b/src/backend/utils/activity/pgstat_subscription.c
@@ -117,11 +117,13 @@ pgstat_fetch_stat_subscription(Oid subid)
* false without flushing the entry. Otherwise returns true.
*/
bool
-pgstat_subscription_flush_cb(PgStat_EntryRef *entry_ref, bool nowait)
+pgstat_subscription_flush_cb(PgStat_EntryRef *entry_ref, bool nowait, bool anytime_only)
{
PgStat_BackendSubEntry *localent;
PgStatShared_Subscription *shsubent;
+ Assert(!anytime_only);
+
localent = (PgStat_BackendSubEntry *) entry_ref->pending;
shsubent = (PgStatShared_Subscription *) entry_ref->shared_stats;
diff --git a/src/backend/utils/activity/pgstat_wal.c b/src/backend/utils/activity/pgstat_wal.c
index 183e0a7a97b..2c2f3f10e10 100644
--- a/src/backend/utils/activity/pgstat_wal.c
+++ b/src/backend/utils/activity/pgstat_wal.c
@@ -51,12 +51,12 @@ pgstat_report_wal(bool force)
nowait = !force;
/* flush wal stats */
- (void) pgstat_wal_flush_cb(nowait);
- pgstat_flush_backend(nowait, PGSTAT_BACKEND_FLUSH_WAL);
+ (void) pgstat_wal_flush_cb(nowait, true);
+ (void) pgstat_flush_backend(nowait, PGSTAT_BACKEND_FLUSH_WAL, true);
/* flush IO stats */
- pgstat_flush_io(nowait);
- (void) pgstat_flush_backend(nowait, PGSTAT_BACKEND_FLUSH_IO);
+ pgstat_flush_io(nowait, true);
+ (void) pgstat_flush_backend(nowait, PGSTAT_BACKEND_FLUSH_IO, true);
}
/*
@@ -88,7 +88,7 @@ pgstat_wal_have_pending(void)
* acquired. Otherwise return false.
*/
bool
-pgstat_wal_flush_cb(bool nowait)
+pgstat_wal_flush_cb(bool nowait, bool anytime_only)
{
PgStatShared_Wal *stats_shmem = &pgStatLocal.shmem->wal;
WalUsage wal_usage_diff = {0};
diff --git a/src/backend/utils/init/globals.c b/src/backend/utils/init/globals.c
index 36ad708b360..ad44826c39e 100644
--- a/src/backend/utils/init/globals.c
+++ b/src/backend/utils/init/globals.c
@@ -40,6 +40,7 @@ volatile sig_atomic_t IdleSessionTimeoutPending = false;
volatile sig_atomic_t ProcSignalBarrierPending = false;
volatile sig_atomic_t LogMemoryContextPending = false;
volatile sig_atomic_t IdleStatsUpdateTimeoutPending = false;
+volatile sig_atomic_t AnytimeStatsUpdateTimeoutPending = false;
volatile uint32 InterruptHoldoffCount = 0;
volatile uint32 QueryCancelHoldoffCount = 0;
volatile uint32 CritSectionCount = 0;
diff --git a/src/backend/utils/init/postinit.c b/src/backend/utils/init/postinit.c
index b59e08605cc..eeeac1bf39a 100644
--- a/src/backend/utils/init/postinit.c
+++ b/src/backend/utils/init/postinit.c
@@ -64,6 +64,7 @@
#include "utils/injection_point.h"
#include "utils/memutils.h"
#include "utils/pg_locale.h"
+#include "utils/pgstat_internal.h"
#include "utils/portal.h"
#include "utils/ps_status.h"
#include "utils/snapmgr.h"
@@ -773,6 +774,8 @@ InitPostgres(const char *in_dbname, Oid dboid,
RegisterTimeout(CLIENT_CONNECTION_CHECK_TIMEOUT, ClientCheckTimeoutHandler);
RegisterTimeout(IDLE_STATS_UPDATE_TIMEOUT,
IdleStatsUpdateTimeoutHandler);
+ RegisterTimeout(ANYTIME_STATS_UPDATE_TIMEOUT,
+ AnytimeStatsUpdateTimeoutHandler);
}
/*
diff --git a/src/include/miscadmin.h b/src/include/miscadmin.h
index f16f35659b9..84e698da214 100644
--- a/src/include/miscadmin.h
+++ b/src/include/miscadmin.h
@@ -96,6 +96,7 @@ extern PGDLLIMPORT volatile sig_atomic_t IdleSessionTimeoutPending;
extern PGDLLIMPORT volatile sig_atomic_t ProcSignalBarrierPending;
extern PGDLLIMPORT volatile sig_atomic_t LogMemoryContextPending;
extern PGDLLIMPORT volatile sig_atomic_t IdleStatsUpdateTimeoutPending;
+extern PGDLLIMPORT volatile sig_atomic_t AnytimeStatsUpdateTimeoutPending;
extern PGDLLIMPORT volatile sig_atomic_t CheckClientConnectionPending;
extern PGDLLIMPORT volatile sig_atomic_t ClientConnectionLost;
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 9bb777c3d5a..b011a315679 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -34,6 +34,9 @@
/* Default directory to store temporary statistics data in */
#define PG_STAT_TMP_DIR "pg_stat_tmp"
+/* Minimum interval non-forced stats flushes */
+#define PGSTAT_MIN_INTERVAL 1000
+
/* Values for track_functions GUC variable --- order is significant! */
typedef enum TrackFunctionsLevel
{
@@ -532,8 +535,24 @@ extern void pgstat_initialize(void);
/* Functions called from backends */
extern long pgstat_report_stat(bool force);
+extern void pgstat_report_anytime_stat(bool force);
extern void pgstat_force_next_flush(void);
+/*
+ * Schedule the next anytime stats update timeout.
+ *
+ * This should be called whenever accumulating statistics that support
+ * FLUSH_ANYTIME flushing mode.
+ */
+#define pgstat_schedule_anytime_update() \
+ do { \
+ if (IsUnderPostmaster && !pgstat_pending_anytime) \
+ { \
+ enable_timeout_after(ANYTIME_STATS_UPDATE_TIMEOUT, PGSTAT_MIN_INTERVAL); \
+ pgstat_pending_anytime = true; \
+ } \
+ } while (0)
+
extern void pgstat_reset_counters(void);
extern void pgstat_reset(PgStat_Kind kind, Oid dboid, uint64 objid);
extern void pgstat_reset_of_kind(PgStat_Kind kind);
@@ -806,6 +825,8 @@ extern PgStat_WalStats *pgstat_fetch_stat_wal(void);
* Variables in pgstat.c
*/
+extern PGDLLIMPORT bool pgstat_pending_anytime;
+
/* GUC parameters */
extern PGDLLIMPORT bool pgstat_track_counts;
extern PGDLLIMPORT int pgstat_track_functions;
@@ -849,4 +870,5 @@ extern PGDLLIMPORT PgStat_Counter pgStatTransactionIdleTime;
/* updated by the traffic cop and in errfinish() */
extern PGDLLIMPORT SessionEndType pgStatSessionEndCause;
+
#endif /* PGSTAT_H */
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 9b8fbae00ed..607f4255268 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -224,6 +224,19 @@ typedef struct PgStat_SubXactStatus
PgStat_TableXactStatus *first; /* head of list for this subxact */
} PgStat_SubXactStatus;
+/*
+ * Flush mode for statistics kinds.
+ *
+ * FLUSH_AT_TXN_BOUNDARY has to be the first because we want it to be the
+ * default value.
+ */
+typedef enum PgStat_FlushMode
+{
+ FLUSH_AT_TXN_BOUNDARY, /* All fields can only be flushed at
+ * transaction boundary */
+ FLUSH_ANYTIME, /* All fields can be flushed anytime,
+ * including within transactions */
+} PgStat_FlushMode;
/*
* Metadata for a specific kind of statistics.
@@ -251,6 +264,16 @@ typedef struct PgStat_KindInfo
*/
bool track_entry_count:1;
+ /*
+ * The mode of when to flush stats. See PgStat_FlushMode for more details.
+ *
+ * This member only has meaning for statistics kinds that accumulate
+ * pending stats and use flush callbacks. For kinds that write directly to
+ * shared memory (e.g., archiver, bgwriter, checkpointer), this member has
+ * no effect.
+ */
+ PgStat_FlushMode flush_mode;
+
/*
* The size of an entry in the shared stats hash table (pointed to by
* PgStatShared_HashEntry->body). For fixed-numbered statistics, this is
@@ -297,8 +320,10 @@ typedef struct PgStat_KindInfo
* For variable-numbered stats: flush pending stats. Required if pending
* data is used. See flush_static_cb when dealing with stats data that
* that cannot use PgStat_EntryRef->pending.
+ *
+ * The anytime_only parameter indicates whether this is an anytime flush.
*/
- bool (*flush_pending_cb) (PgStat_EntryRef *sr, bool nowait);
+ bool (*flush_pending_cb) (PgStat_EntryRef *sr, bool nowait, bool anytime_only);
/*
* For variable-numbered stats: delete pending stats. Optional.
@@ -366,8 +391,10 @@ typedef struct PgStat_KindInfo
*
* "pgstat_report_fixed" needs to be set to trigger the flush of pending
* stats.
+ *
+ * The anytime_only parameter indicates whether this is an anytime flush.
*/
- bool (*flush_static_cb) (bool nowait);
+ bool (*flush_static_cb) (bool nowait, bool anytime_only);
/*
* For fixed-numbered statistics: Reset All.
@@ -677,6 +704,7 @@ extern PgStat_EntryRef *pgstat_fetch_pending_entry(PgStat_Kind kind,
extern void *pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid);
extern void pgstat_snapshot_fixed(PgStat_Kind kind);
+extern void AnytimeStatsUpdateTimeoutHandler(void);
/*
@@ -696,8 +724,8 @@ extern void pgstat_archiver_snapshot_cb(void);
#define PGSTAT_BACKEND_FLUSH_WAL (1 << 1) /* Flush WAL statistics */
#define PGSTAT_BACKEND_FLUSH_ALL (PGSTAT_BACKEND_FLUSH_IO | PGSTAT_BACKEND_FLUSH_WAL)
-extern bool pgstat_flush_backend(bool nowait, bits32 flags);
-extern bool pgstat_backend_flush_cb(bool nowait);
+extern bool pgstat_flush_backend(bool nowait, bits32 flags, bool anytime_only);
+extern bool pgstat_backend_flush_cb(bool nowait, bool anytime_only);
extern void pgstat_backend_reset_timestamp_cb(PgStatShared_Common *header,
TimestampTz ts);
@@ -729,7 +757,7 @@ extern void AtEOXact_PgStat_Database(bool isCommit, bool parallel);
extern PgStat_StatDBEntry *pgstat_prep_database_pending(Oid dboid);
extern void pgstat_reset_database_timestamp(Oid dboid, TimestampTz ts);
-extern bool pgstat_database_flush_cb(PgStat_EntryRef *entry_ref, bool nowait);
+extern bool pgstat_database_flush_cb(PgStat_EntryRef *entry_ref, bool nowait, bool anytime_only);
extern void pgstat_database_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts);
@@ -737,7 +765,7 @@ extern void pgstat_database_reset_timestamp_cb(PgStatShared_Common *header, Time
* Functions in pgstat_function.c
*/
-extern bool pgstat_function_flush_cb(PgStat_EntryRef *entry_ref, bool nowait);
+extern bool pgstat_function_flush_cb(PgStat_EntryRef *entry_ref, bool nowait, bool anytime_only);
extern void pgstat_function_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts);
@@ -745,9 +773,9 @@ extern void pgstat_function_reset_timestamp_cb(PgStatShared_Common *header, Time
* Functions in pgstat_io.c
*/
-extern void pgstat_flush_io(bool nowait);
+extern void pgstat_flush_io(bool nowait, bool anytime_only);
-extern bool pgstat_io_flush_cb(bool nowait);
+extern bool pgstat_io_flush_cb(bool nowait, bool anytime_only);
extern void pgstat_io_init_shmem_cb(void *stats);
extern void pgstat_io_reset_all_cb(TimestampTz ts);
extern void pgstat_io_snapshot_cb(void);
@@ -762,7 +790,7 @@ extern void AtEOSubXact_PgStat_Relations(PgStat_SubXactStatus *xact_state, bool
extern void AtPrepare_PgStat_Relations(PgStat_SubXactStatus *xact_state);
extern void PostPrepare_PgStat_Relations(PgStat_SubXactStatus *xact_state);
-extern bool pgstat_relation_flush_cb(PgStat_EntryRef *entry_ref, bool nowait);
+extern bool pgstat_relation_flush_cb(PgStat_EntryRef *entry_ref, bool nowait, bool anytime_only);
extern void pgstat_relation_delete_pending_cb(PgStat_EntryRef *entry_ref);
extern void pgstat_relation_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts);
@@ -809,7 +837,7 @@ extern PgStatShared_Common *pgstat_init_entry(PgStat_Kind kind,
* Functions in pgstat_slru.c
*/
-extern bool pgstat_slru_flush_cb(bool nowait);
+extern bool pgstat_slru_flush_cb(bool nowait, bool anytime_only);
extern void pgstat_slru_init_shmem_cb(void *stats);
extern void pgstat_slru_reset_all_cb(TimestampTz ts);
extern void pgstat_slru_snapshot_cb(void);
@@ -820,7 +848,7 @@ extern void pgstat_slru_snapshot_cb(void);
*/
extern void pgstat_wal_init_backend_cb(void);
-extern bool pgstat_wal_flush_cb(bool nowait);
+extern bool pgstat_wal_flush_cb(bool nowait, bool anytime_only);
extern void pgstat_wal_init_shmem_cb(void *stats);
extern void pgstat_wal_reset_all_cb(TimestampTz ts);
extern void pgstat_wal_snapshot_cb(void);
@@ -830,7 +858,7 @@ extern void pgstat_wal_snapshot_cb(void);
* Functions in pgstat_subscription.c
*/
-extern bool pgstat_subscription_flush_cb(PgStat_EntryRef *entry_ref, bool nowait);
+extern bool pgstat_subscription_flush_cb(PgStat_EntryRef *entry_ref, bool nowait, bool anytime_only);
extern void pgstat_subscription_reset_timestamp_cb(PgStatShared_Common *header, TimestampTz ts);
diff --git a/src/include/utils/timeout.h b/src/include/utils/timeout.h
index 0965b590b34..10723bb664c 100644
--- a/src/include/utils/timeout.h
+++ b/src/include/utils/timeout.h
@@ -35,6 +35,7 @@ typedef enum TimeoutId
IDLE_SESSION_TIMEOUT,
IDLE_STATS_UPDATE_TIMEOUT,
CLIENT_CONNECTION_CHECK_TIMEOUT,
+ ANYTIME_STATS_UPDATE_TIMEOUT,
STARTUP_PROGRESS_TIMEOUT,
/* First user-definable timeout reason */
USER_TIMEOUT,
diff --git a/src/test/modules/test_custom_stats/test_custom_var_stats.c b/src/test/modules/test_custom_stats/test_custom_var_stats.c
index da28afbd929..4c207611236 100644
--- a/src/test/modules/test_custom_stats/test_custom_var_stats.c
+++ b/src/test/modules/test_custom_stats/test_custom_var_stats.c
@@ -84,7 +84,7 @@ static dsa_area *custom_stats_description_dsa = NULL;
/* Flush callback: merge pending stats into shared memory */
static bool test_custom_stats_var_flush_pending_cb(PgStat_EntryRef *entry_ref,
- bool nowait);
+ bool nowait, bool anytime_only);
/* Serialization callback: write auxiliary entry data */
static void test_custom_stats_var_to_serialized_data(const PgStat_HashKey *key,
@@ -151,7 +151,7 @@ _PG_init(void)
* Returns false only if nowait=true and lock acquisition fails.
*/
static bool
-test_custom_stats_var_flush_pending_cb(PgStat_EntryRef *entry_ref, bool nowait)
+test_custom_stats_var_flush_pending_cb(PgStat_EntryRef *entry_ref, bool nowait, bool anytime_only)
{
PgStat_StatCustomVarEntry *pending_entry;
PgStatShared_CustomVarEntry *shared_entry;
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 241945734ec..1dbc4b96f51 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -2271,6 +2271,7 @@ PgStat_Counter
PgStat_EntryRef
PgStat_EntryRefHashEntry
PgStat_FetchConsistency
+PgStat_FlushMode
PgStat_FunctionCallUsage
PgStat_FunctionCounts
PgStat_HashKey
--
2.34.1
--2MEBAGW8+kohXisi
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v11-0002-Add-anytime-flush-tests-for-custom-stats.patch"
^ permalink raw reply [nested|flat] 12+ messages in thread
* [PATCH v1 1/3] Add pgstat_report_anytime_stat() for periodic stats flushing
@ 2026-01-05 09:41 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 12+ messages in thread
From: Bertrand Drouvot @ 2026-01-05 09:41 UTC (permalink / raw)
Long running transactions can accumulate significant statistics (WAL, IO, ...)
that remain unflushed until the transaction ends. This delays visibility of
resource usage in monitoring views like pg_stat_io and pg_stat_wal.
This commit introduces pgstat_report_anytime_stat(), which flushes
non transactional statistics even inside active transactions. A new timeout
handler fires every second to call this function, ensuring timely stats visibility
without waiting for transaction completion.
Implementation details:
- Add PgStat_FlushBehavior enum to classify stats kinds:
* FLUSH_ANYTIME: Stats that can always be flushed (WAL, IO, ...)
* FLUSH_AT_TXN_BOUNDARY: Stats requiring transaction boundaries
- Modify pgstat_flush_pending_entries() and pgstat_flush_fixed_stats()
to accept a boolean anytime_only parameter:
* When false: flushes all stats (existing behavior)
* When true: flushes only FLUSH_ANYTIME stats and skips FLUSH_AT_TXN_BOUNDARY stats
- Register ANYTIME_STATS_UPDATE_TIMEOUT that fires every 1 second, calling
pgstat_report_anytime_stat(false)
The force parameter in pgstat_report_anytime_stat() is currently unused (always
called with force=false) but reserved for future use cases requiring immediate
flushing.
---
src/backend/tcop/postgres.c | 18 +++++
src/backend/utils/activity/pgstat.c | 119 ++++++++++++++++++++++++----
src/backend/utils/init/globals.c | 1 +
src/backend/utils/init/postinit.c | 15 ++++
src/include/miscadmin.h | 1 +
src/include/pgstat.h | 4 +
src/include/utils/pgstat_internal.h | 11 +++
src/include/utils/timeout.h | 1 +
src/tools/pgindent/typedefs.list | 1 +
9 files changed, 154 insertions(+), 17 deletions(-)
9.7% src/backend/tcop/
70.2% src/backend/utils/activity/
9.3% src/backend/utils/init/
6.0% src/include/utils/
4.3% src/include/
diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c
index e54bf1e760f..6a91543f80a 100644
--- a/src/backend/tcop/postgres.c
+++ b/src/backend/tcop/postgres.c
@@ -3530,6 +3530,24 @@ ProcessInterrupts(void)
pgstat_report_stat(true);
}
+ /*
+ * Flush stats outside of transaction boundary if the timeout fired.
+ * Unlike transactional stats, these can be flushed even inside a running
+ * transaction.
+ */
+ if (AnytimeStatsUpdateTimeoutPending)
+ {
+ AnytimeStatsUpdateTimeoutPending = false;
+
+ /* Skip if completely idle */
+ if (!DoingCommandRead || IsTransactionOrTransactionBlock())
+ pgstat_report_anytime_stat(false);
+
+ /* Schedule next timeout */
+ enable_timeout_after(ANYTIME_STATS_UPDATE_TIMEOUT,
+ PGSTAT_ANYTIME_FLUSH_INTERVAL);
+ }
+
if (ProcSignalBarrierPending)
ProcessProcSignalBarrier();
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index 11bb71cad5a..f7942e47475 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -187,7 +187,8 @@ static void pgstat_init_snapshot_fixed(void);
static void pgstat_reset_after_failure(void);
-static bool pgstat_flush_pending_entries(bool nowait);
+static bool pgstat_flush_pending_entries(bool nowait, bool anytime_only);
+static bool pgstat_flush_fixed_stats(bool nowait, bool anytime_only);
static void pgstat_prep_snapshot(void);
static void pgstat_build_snapshot(void);
@@ -288,6 +289,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = true,
+ .flush_behavior = FLUSH_AT_TXN_BOUNDARY,
/* so pg_stat_database entries can be seen in all databases */
.accessed_across_databases = true,
@@ -305,6 +307,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = true,
+ .flush_behavior = FLUSH_AT_TXN_BOUNDARY,
.shared_size = sizeof(PgStatShared_Relation),
.shared_data_off = offsetof(PgStatShared_Relation, stats),
@@ -321,6 +324,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = true,
+ .flush_behavior = FLUSH_AT_TXN_BOUNDARY,
.shared_size = sizeof(PgStatShared_Function),
.shared_data_off = offsetof(PgStatShared_Function, stats),
@@ -336,6 +340,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = true,
+ .flush_behavior = FLUSH_AT_TXN_BOUNDARY,
.accessed_across_databases = true,
@@ -353,6 +358,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = true,
+ .flush_behavior = FLUSH_AT_TXN_BOUNDARY,
/* so pg_stat_subscription_stats entries can be seen in all databases */
.accessed_across_databases = true,
@@ -370,6 +376,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = false,
+ .flush_behavior = FLUSH_ANYTIME,
.accessed_across_databases = true,
@@ -388,6 +395,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = true,
.write_to_file = true,
+ .flush_behavior = FLUSH_ANYTIME,
.snapshot_ctl_off = offsetof(PgStat_Snapshot, archiver),
.shared_ctl_off = offsetof(PgStat_ShmemControl, archiver),
@@ -404,6 +412,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = true,
.write_to_file = true,
+ .flush_behavior = FLUSH_ANYTIME,
.snapshot_ctl_off = offsetof(PgStat_Snapshot, bgwriter),
.shared_ctl_off = offsetof(PgStat_ShmemControl, bgwriter),
@@ -420,6 +429,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = true,
.write_to_file = true,
+ .flush_behavior = FLUSH_ANYTIME,
.snapshot_ctl_off = offsetof(PgStat_Snapshot, checkpointer),
.shared_ctl_off = offsetof(PgStat_ShmemControl, checkpointer),
@@ -436,6 +446,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = true,
.write_to_file = true,
+ .flush_behavior = FLUSH_ANYTIME,
.snapshot_ctl_off = offsetof(PgStat_Snapshot, io),
.shared_ctl_off = offsetof(PgStat_ShmemControl, io),
@@ -453,6 +464,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = true,
.write_to_file = true,
+ .flush_behavior = FLUSH_ANYTIME,
.snapshot_ctl_off = offsetof(PgStat_Snapshot, slru),
.shared_ctl_off = offsetof(PgStat_ShmemControl, slru),
@@ -470,6 +482,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = true,
.write_to_file = true,
+ .flush_behavior = FLUSH_ANYTIME,
.snapshot_ctl_off = offsetof(PgStat_Snapshot, wal),
.shared_ctl_off = offsetof(PgStat_ShmemControl, wal),
@@ -775,23 +788,11 @@ pgstat_report_stat(bool force)
partial_flush = false;
/* flush of variable-numbered stats tracked in pending entries list */
- partial_flush |= pgstat_flush_pending_entries(nowait);
+ partial_flush |= pgstat_flush_pending_entries(nowait, false);
/* flush of other stats kinds */
if (pgstat_report_fixed)
- {
- for (PgStat_Kind kind = PGSTAT_KIND_MIN; kind <= PGSTAT_KIND_MAX; kind++)
- {
- const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
-
- if (!kind_info)
- continue;
- if (!kind_info->flush_static_cb)
- continue;
-
- partial_flush |= kind_info->flush_static_cb(nowait);
- }
- }
+ partial_flush |= pgstat_flush_fixed_stats(nowait, false);
last_flush = now;
@@ -1345,9 +1346,14 @@ pgstat_delete_pending_entry(PgStat_EntryRef *entry_ref)
/*
* Flush out pending variable-numbered stats.
+ *
+ * If anytime_only is true, only flushes FLUSH_ANYTIME entries.
+ * This is safe to call inside transactions.
+ *
+ * If anytime_only is false, flushes all entries.
*/
static bool
-pgstat_flush_pending_entries(bool nowait)
+pgstat_flush_pending_entries(bool nowait, bool anytime_only)
{
bool have_pending = false;
dlist_node *cur = NULL;
@@ -1377,6 +1383,20 @@ pgstat_flush_pending_entries(bool nowait)
Assert(!kind_info->fixed_amount);
Assert(kind_info->flush_pending_cb != NULL);
+ /* Skip transactional stats if we're in anytime_only mode */
+ if (anytime_only && kind_info->flush_behavior == FLUSH_AT_TXN_BOUNDARY)
+ {
+ have_pending = true;
+
+ if (dlist_has_next(&pgStatPending, cur))
+ next = dlist_next_node(&pgStatPending, cur);
+ else
+ next = NULL;
+
+ cur = next;
+ continue;
+ }
+
/* flush the stats, if possible */
did_flush = kind_info->flush_pending_cb(entry_ref, nowait);
@@ -1397,11 +1417,42 @@ pgstat_flush_pending_entries(bool nowait)
cur = next;
}
- Assert(dlist_is_empty(&pgStatPending) == !have_pending);
+ /*
+ * When in anytime_only mode, the list may not be empty because
+ * FLUSH_AT_TXN_BOUNDARY entries were skipped.
+ */
+ Assert(!anytime_only || dlist_is_empty(&pgStatPending) == !have_pending);
return have_pending;
}
+/*
+ * Flush fixed-amount stats.
+ *
+ * If anytime_only is true, only flushes FLUSH_ANYTIME stats (safe inside transactions).
+ * If anytime_only is false, flushes all stats with flush_static_cb.
+ */
+static bool
+pgstat_flush_fixed_stats(bool nowait, bool anytime_only)
+{
+ bool partial_flush = false;
+
+ for (PgStat_Kind kind = PGSTAT_KIND_MIN; kind <= PGSTAT_KIND_MAX; kind++)
+ {
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (!kind_info || !kind_info->flush_static_cb)
+ continue;
+
+ /* Skip transactional stats if we're in anytime_only mode */
+ if (anytime_only && kind_info->flush_behavior == FLUSH_AT_TXN_BOUNDARY)
+ continue;
+
+ partial_flush |= kind_info->flush_static_cb(nowait);
+ }
+
+ return partial_flush;
+}
/* ------------------------------------------------------------
* Helper / infrastructure functions
@@ -2119,3 +2170,37 @@ assign_stats_fetch_consistency(int newval, void *extra)
if (pgstat_fetch_consistency != newval)
force_stats_snapshot_clear = true;
}
+
+/*
+ * Flush non-transactional stats
+ *
+ * This is safe to call even inside a transaction. It only flushes stats
+ * kinds marked as FLUSH_ANYTIME.
+ *
+ * This allows long running transactions to report activity without waiting
+ * for transaction to finish.
+ */
+void
+pgstat_report_anytime_stat(bool force)
+{
+ bool nowait = !force;
+
+ pgstat_assert_is_up();
+
+ /*
+ * Exit if no pending stats at all. This avoids unnecessary work when
+ * backends are idle or in sessions without stats accumulation.
+ *
+ * Note: This check isn't precise as there might be only transactional
+ * stats pending, which we'll skip during the flush. However, maintaining
+ * precise tracking would add complexity that does not seem worth it from
+ * a performance point of view (no noticeable performance regression has
+ * been observed with the current implementation).
+ */
+ if (dlist_is_empty(&pgStatPending) && !pgstat_report_fixed)
+ return;
+
+ /* Flush stats outside of transaction boundary */
+ pgstat_flush_pending_entries(nowait, true);
+ pgstat_flush_fixed_stats(nowait, true);
+}
diff --git a/src/backend/utils/init/globals.c b/src/backend/utils/init/globals.c
index 36ad708b360..ad44826c39e 100644
--- a/src/backend/utils/init/globals.c
+++ b/src/backend/utils/init/globals.c
@@ -40,6 +40,7 @@ volatile sig_atomic_t IdleSessionTimeoutPending = false;
volatile sig_atomic_t ProcSignalBarrierPending = false;
volatile sig_atomic_t LogMemoryContextPending = false;
volatile sig_atomic_t IdleStatsUpdateTimeoutPending = false;
+volatile sig_atomic_t AnytimeStatsUpdateTimeoutPending = false;
volatile uint32 InterruptHoldoffCount = 0;
volatile uint32 QueryCancelHoldoffCount = 0;
volatile uint32 CritSectionCount = 0;
diff --git a/src/backend/utils/init/postinit.c b/src/backend/utils/init/postinit.c
index 3f401faf3de..cb0f6aecad1 100644
--- a/src/backend/utils/init/postinit.c
+++ b/src/backend/utils/init/postinit.c
@@ -82,6 +82,7 @@ static void TransactionTimeoutHandler(void);
static void IdleSessionTimeoutHandler(void);
static void IdleStatsUpdateTimeoutHandler(void);
static void ClientCheckTimeoutHandler(void);
+static void AnytimeStatsUpdateTimeoutHandler(void);
static bool ThereIsAtLeastOneRole(void);
static void process_startup_options(Port *port, bool am_superuser);
static void process_settings(Oid databaseid, Oid roleid);
@@ -765,6 +766,9 @@ InitPostgres(const char *in_dbname, Oid dboid,
RegisterTimeout(CLIENT_CONNECTION_CHECK_TIMEOUT, ClientCheckTimeoutHandler);
RegisterTimeout(IDLE_STATS_UPDATE_TIMEOUT,
IdleStatsUpdateTimeoutHandler);
+ RegisterTimeout(ANYTIME_STATS_UPDATE_TIMEOUT,
+ AnytimeStatsUpdateTimeoutHandler);
+ enable_timeout_after(ANYTIME_STATS_UPDATE_TIMEOUT, PGSTAT_ANYTIME_FLUSH_INTERVAL);
}
/*
@@ -1446,3 +1450,14 @@ ThereIsAtLeastOneRole(void)
return result;
}
+
+/*
+ * Timeout handler for flushing non-transactional stats.
+ */
+static void
+AnytimeStatsUpdateTimeoutHandler(void)
+{
+ AnytimeStatsUpdateTimeoutPending = true;
+ InterruptPending = true;
+ SetLatch(MyLatch);
+}
diff --git a/src/include/miscadmin.h b/src/include/miscadmin.h
index db559b39c4d..8aeb9628871 100644
--- a/src/include/miscadmin.h
+++ b/src/include/miscadmin.h
@@ -96,6 +96,7 @@ extern PGDLLIMPORT volatile sig_atomic_t IdleSessionTimeoutPending;
extern PGDLLIMPORT volatile sig_atomic_t ProcSignalBarrierPending;
extern PGDLLIMPORT volatile sig_atomic_t LogMemoryContextPending;
extern PGDLLIMPORT volatile sig_atomic_t IdleStatsUpdateTimeoutPending;
+extern PGDLLIMPORT volatile sig_atomic_t AnytimeStatsUpdateTimeoutPending;
extern PGDLLIMPORT volatile sig_atomic_t CheckClientConnectionPending;
extern PGDLLIMPORT volatile sig_atomic_t ClientConnectionLost;
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index fff7ecc2533..86e65397614 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -35,6 +35,9 @@
/* Default directory to store temporary statistics data in */
#define PG_STAT_TMP_DIR "pg_stat_tmp"
+/* When to call pgstat_report_anytime_stat() again */
+#define PGSTAT_ANYTIME_FLUSH_INTERVAL 1000
+
/* Values for track_functions GUC variable --- order is significant! */
typedef enum TrackFunctionsLevel
{
@@ -533,6 +536,7 @@ extern void pgstat_initialize(void);
/* Functions called from backends */
extern long pgstat_report_stat(bool force);
+extern void pgstat_report_anytime_stat(bool force);
extern void pgstat_force_next_flush(void);
extern void pgstat_reset_counters(void);
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 9b8fbae00ed..02f4f13fc0f 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -224,6 +224,14 @@ typedef struct PgStat_SubXactStatus
PgStat_TableXactStatus *first; /* head of list for this subxact */
} PgStat_SubXactStatus;
+/*
+ * Flush behavior for statistics kinds.
+ */
+typedef enum PgStat_FlushBehavior
+{
+ FLUSH_ANYTIME, /* All fields can flush anytime */
+ FLUSH_AT_TXN_BOUNDARY, /* All fields need transaction boundary */
+} PgStat_FlushBehavior;
/*
* Metadata for a specific kind of statistics.
@@ -251,6 +259,9 @@ typedef struct PgStat_KindInfo
*/
bool track_entry_count:1;
+ /* Flush behavior */
+ PgStat_FlushBehavior flush_behavior;
+
/*
* The size of an entry in the shared stats hash table (pointed to by
* PgStatShared_HashEntry->body). For fixed-numbered statistics, this is
diff --git a/src/include/utils/timeout.h b/src/include/utils/timeout.h
index 0965b590b34..10723bb664c 100644
--- a/src/include/utils/timeout.h
+++ b/src/include/utils/timeout.h
@@ -35,6 +35,7 @@ typedef enum TimeoutId
IDLE_SESSION_TIMEOUT,
IDLE_STATS_UPDATE_TIMEOUT,
CLIENT_CONNECTION_CHECK_TIMEOUT,
+ ANYTIME_STATS_UPDATE_TIMEOUT,
STARTUP_PROGRESS_TIMEOUT,
/* First user-definable timeout reason */
USER_TIMEOUT,
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 09e7f1d420e..9aabb325f16 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -2261,6 +2261,7 @@ PgStat_Counter
PgStat_EntryRef
PgStat_EntryRefHashEntry
PgStat_FetchConsistency
+PgStat_FlushBehavior
PgStat_FunctionCallUsage
PgStat_FunctionCounts
PgStat_HashKey
--
2.34.1
--tjEWjIIwfNIHQLgt
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v1-0002-Remove-useless-calls-to-flush-some-stats.patch"
^ permalink raw reply [nested|flat] 12+ messages in thread
* [PATCH v2 1/3] Add pgstat_report_anytime_stat() for periodic stats flushing
@ 2026-01-05 09:41 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 12+ messages in thread
From: Bertrand Drouvot @ 2026-01-05 09:41 UTC (permalink / raw)
Long running transactions can accumulate significant statistics (WAL, IO, ...)
that remain unflushed until the transaction ends. This delays visibility of
resource usage in monitoring views like pg_stat_io and pg_stat_wal.
This commit introduces pgstat_report_anytime_stat(), which flushes
non transactional statistics even inside active transactions. A new timeout
handler fires every second to call this function, ensuring timely stats visibility
without waiting for transaction completion.
Implementation details:
- Add PgStat_FlushBehavior enum to classify stats kinds:
* FLUSH_ANYTIME: Stats that can always be flushed (WAL, IO, ...)
* FLUSH_AT_TXN_BOUNDARY: Stats requiring transaction boundaries
- Modify pgstat_flush_pending_entries() and pgstat_flush_fixed_stats()
to accept a boolean anytime_only parameter:
* When false: flushes all stats (existing behavior)
* When true: flushes only FLUSH_ANYTIME stats and skips FLUSH_AT_TXN_BOUNDARY stats
- Register ANYTIME_STATS_UPDATE_TIMEOUT that fires every 1 second, calling
pgstat_report_anytime_stat(false)
The force parameter in pgstat_report_anytime_stat() is currently unused (always
called with force=false) but reserved for future use cases requiring immediate
flushing.
---
src/backend/tcop/postgres.c | 16 ++++
src/backend/utils/activity/pgstat.c | 113 ++++++++++++++++++++++++----
src/backend/utils/init/globals.c | 1 +
src/backend/utils/init/postinit.c | 15 ++++
src/include/miscadmin.h | 1 +
src/include/pgstat.h | 4 +
src/include/utils/pgstat_internal.h | 13 ++++
src/include/utils/timeout.h | 1 +
src/tools/pgindent/typedefs.list | 1 +
9 files changed, 149 insertions(+), 16 deletions(-)
8.2% src/backend/tcop/
69.3% src/backend/utils/activity/
9.7% src/backend/utils/init/
7.7% src/include/utils/
4.5% src/include/
diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c
index e54bf1e760f..9c4a9078ee0 100644
--- a/src/backend/tcop/postgres.c
+++ b/src/backend/tcop/postgres.c
@@ -3530,6 +3530,22 @@ ProcessInterrupts(void)
pgstat_report_stat(true);
}
+ /*
+ * Flush stats outside of transaction boundary if the timeout fired.
+ * Unlike transactional stats, these can be flushed even inside a running
+ * transaction.
+ */
+ if (AnytimeStatsUpdateTimeoutPending)
+ {
+ AnytimeStatsUpdateTimeoutPending = false;
+
+ pgstat_report_anytime_stat(false);
+
+ /* Schedule next timeout */
+ enable_timeout_after(ANYTIME_STATS_UPDATE_TIMEOUT,
+ PGSTAT_ANYTIME_FLUSH_INTERVAL);
+ }
+
if (ProcSignalBarrierPending)
ProcessProcSignalBarrier();
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index 11bb71cad5a..0f45a7d165e 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -187,7 +187,8 @@ static void pgstat_init_snapshot_fixed(void);
static void pgstat_reset_after_failure(void);
-static bool pgstat_flush_pending_entries(bool nowait);
+static bool pgstat_flush_pending_entries(bool nowait, bool anytime_only);
+static bool pgstat_flush_fixed_stats(bool nowait, bool anytime_only);
static void pgstat_prep_snapshot(void);
static void pgstat_build_snapshot(void);
@@ -288,6 +289,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = true,
+ .flush_behavior = FLUSH_AT_TXN_BOUNDARY,
/* so pg_stat_database entries can be seen in all databases */
.accessed_across_databases = true,
@@ -305,6 +307,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = true,
+ .flush_behavior = FLUSH_AT_TXN_BOUNDARY,
.shared_size = sizeof(PgStatShared_Relation),
.shared_data_off = offsetof(PgStatShared_Relation, stats),
@@ -321,6 +324,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = true,
+ .flush_behavior = FLUSH_AT_TXN_BOUNDARY,
.shared_size = sizeof(PgStatShared_Function),
.shared_data_off = offsetof(PgStatShared_Function, stats),
@@ -336,6 +340,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = true,
+ .flush_behavior = FLUSH_AT_TXN_BOUNDARY,
.accessed_across_databases = true,
@@ -353,6 +358,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = true,
+ .flush_behavior = FLUSH_AT_TXN_BOUNDARY,
/* so pg_stat_subscription_stats entries can be seen in all databases */
.accessed_across_databases = true,
@@ -370,6 +376,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = false,
+ .flush_behavior = FLUSH_ANYTIME,
.accessed_across_databases = true,
@@ -388,6 +395,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = true,
.write_to_file = true,
+ .flush_behavior = FLUSH_ANYTIME,
.snapshot_ctl_off = offsetof(PgStat_Snapshot, archiver),
.shared_ctl_off = offsetof(PgStat_ShmemControl, archiver),
@@ -404,6 +412,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = true,
.write_to_file = true,
+ .flush_behavior = FLUSH_ANYTIME,
.snapshot_ctl_off = offsetof(PgStat_Snapshot, bgwriter),
.shared_ctl_off = offsetof(PgStat_ShmemControl, bgwriter),
@@ -420,6 +429,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = true,
.write_to_file = true,
+ .flush_behavior = FLUSH_ANYTIME,
.snapshot_ctl_off = offsetof(PgStat_Snapshot, checkpointer),
.shared_ctl_off = offsetof(PgStat_ShmemControl, checkpointer),
@@ -436,6 +446,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = true,
.write_to_file = true,
+ .flush_behavior = FLUSH_ANYTIME,
.snapshot_ctl_off = offsetof(PgStat_Snapshot, io),
.shared_ctl_off = offsetof(PgStat_ShmemControl, io),
@@ -453,6 +464,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = true,
.write_to_file = true,
+ .flush_behavior = FLUSH_ANYTIME,
.snapshot_ctl_off = offsetof(PgStat_Snapshot, slru),
.shared_ctl_off = offsetof(PgStat_ShmemControl, slru),
@@ -470,6 +482,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = true,
.write_to_file = true,
+ .flush_behavior = FLUSH_ANYTIME,
.snapshot_ctl_off = offsetof(PgStat_Snapshot, wal),
.shared_ctl_off = offsetof(PgStat_ShmemControl, wal),
@@ -775,23 +788,11 @@ pgstat_report_stat(bool force)
partial_flush = false;
/* flush of variable-numbered stats tracked in pending entries list */
- partial_flush |= pgstat_flush_pending_entries(nowait);
+ partial_flush |= pgstat_flush_pending_entries(nowait, false);
/* flush of other stats kinds */
if (pgstat_report_fixed)
- {
- for (PgStat_Kind kind = PGSTAT_KIND_MIN; kind <= PGSTAT_KIND_MAX; kind++)
- {
- const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
-
- if (!kind_info)
- continue;
- if (!kind_info->flush_static_cb)
- continue;
-
- partial_flush |= kind_info->flush_static_cb(nowait);
- }
- }
+ partial_flush |= pgstat_flush_fixed_stats(nowait, false);
last_flush = now;
@@ -1345,9 +1346,14 @@ pgstat_delete_pending_entry(PgStat_EntryRef *entry_ref)
/*
* Flush out pending variable-numbered stats.
+ *
+ * If anytime_only is true, only flushes FLUSH_ANYTIME entries.
+ * This is safe to call inside transactions.
+ *
+ * If anytime_only is false, flushes all entries.
*/
static bool
-pgstat_flush_pending_entries(bool nowait)
+pgstat_flush_pending_entries(bool nowait, bool anytime_only)
{
bool have_pending = false;
dlist_node *cur = NULL;
@@ -1377,6 +1383,20 @@ pgstat_flush_pending_entries(bool nowait)
Assert(!kind_info->fixed_amount);
Assert(kind_info->flush_pending_cb != NULL);
+ /* Skip transactional stats if we're in anytime_only mode */
+ if (anytime_only && kind_info->flush_behavior == FLUSH_AT_TXN_BOUNDARY)
+ {
+ have_pending = true;
+
+ if (dlist_has_next(&pgStatPending, cur))
+ next = dlist_next_node(&pgStatPending, cur);
+ else
+ next = NULL;
+
+ cur = next;
+ continue;
+ }
+
/* flush the stats, if possible */
did_flush = kind_info->flush_pending_cb(entry_ref, nowait);
@@ -1397,11 +1417,42 @@ pgstat_flush_pending_entries(bool nowait)
cur = next;
}
+ /*
+ * When in anytime_only mode, the list may not be empty because
+ * FLUSH_AT_TXN_BOUNDARY entries were skipped.
+ */
Assert(dlist_is_empty(&pgStatPending) == !have_pending);
return have_pending;
}
+/*
+ * Flush fixed-amount stats.
+ *
+ * If anytime_only is true, only flushes FLUSH_ANYTIME stats (safe inside transactions).
+ * If anytime_only is false, flushes all stats with flush_static_cb.
+ */
+static bool
+pgstat_flush_fixed_stats(bool nowait, bool anytime_only)
+{
+ bool partial_flush = false;
+
+ for (PgStat_Kind kind = PGSTAT_KIND_MIN; kind <= PGSTAT_KIND_MAX; kind++)
+ {
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (!kind_info || !kind_info->flush_static_cb)
+ continue;
+
+ /* Skip transactional stats if we're in anytime_only mode */
+ if (anytime_only && kind_info->flush_behavior == FLUSH_AT_TXN_BOUNDARY)
+ continue;
+
+ partial_flush |= kind_info->flush_static_cb(nowait);
+ }
+
+ return partial_flush;
+}
/* ------------------------------------------------------------
* Helper / infrastructure functions
@@ -2119,3 +2170,33 @@ assign_stats_fetch_consistency(int newval, void *extra)
if (pgstat_fetch_consistency != newval)
force_stats_snapshot_clear = true;
}
+
+/*
+ * Flushes only FLUSH_ANYTIME stats using non-blocking locks. Transactional
+ * stats (FLUSH_AT_TXN_BOUNDARY) remain pending until transaction boundary.
+ * Safe to call inside transactions.
+ */
+void
+pgstat_report_anytime_stat(bool force)
+{
+ bool nowait = !force;
+
+ pgstat_assert_is_up();
+
+ /*
+ * Exit if no pending stats at all. This avoids unnecessary work when
+ * backends are idle or in sessions without stats accumulation.
+ *
+ * Note: This check isn't precise as there might be only transactional
+ * stats pending, which we'll skip during the flush. However, maintaining
+ * precise tracking would add complexity that does not seem worth it from
+ * a performance point of view (no noticeable performance regression has
+ * been observed with the current implementation).
+ */
+ if (dlist_is_empty(&pgStatPending) && !pgstat_report_fixed)
+ return;
+
+ /* Flush stats outside of transaction boundary */
+ pgstat_flush_pending_entries(nowait, true);
+ pgstat_flush_fixed_stats(nowait, true);
+}
diff --git a/src/backend/utils/init/globals.c b/src/backend/utils/init/globals.c
index 36ad708b360..ad44826c39e 100644
--- a/src/backend/utils/init/globals.c
+++ b/src/backend/utils/init/globals.c
@@ -40,6 +40,7 @@ volatile sig_atomic_t IdleSessionTimeoutPending = false;
volatile sig_atomic_t ProcSignalBarrierPending = false;
volatile sig_atomic_t LogMemoryContextPending = false;
volatile sig_atomic_t IdleStatsUpdateTimeoutPending = false;
+volatile sig_atomic_t AnytimeStatsUpdateTimeoutPending = false;
volatile uint32 InterruptHoldoffCount = 0;
volatile uint32 QueryCancelHoldoffCount = 0;
volatile uint32 CritSectionCount = 0;
diff --git a/src/backend/utils/init/postinit.c b/src/backend/utils/init/postinit.c
index 3f401faf3de..cb0f6aecad1 100644
--- a/src/backend/utils/init/postinit.c
+++ b/src/backend/utils/init/postinit.c
@@ -82,6 +82,7 @@ static void TransactionTimeoutHandler(void);
static void IdleSessionTimeoutHandler(void);
static void IdleStatsUpdateTimeoutHandler(void);
static void ClientCheckTimeoutHandler(void);
+static void AnytimeStatsUpdateTimeoutHandler(void);
static bool ThereIsAtLeastOneRole(void);
static void process_startup_options(Port *port, bool am_superuser);
static void process_settings(Oid databaseid, Oid roleid);
@@ -765,6 +766,9 @@ InitPostgres(const char *in_dbname, Oid dboid,
RegisterTimeout(CLIENT_CONNECTION_CHECK_TIMEOUT, ClientCheckTimeoutHandler);
RegisterTimeout(IDLE_STATS_UPDATE_TIMEOUT,
IdleStatsUpdateTimeoutHandler);
+ RegisterTimeout(ANYTIME_STATS_UPDATE_TIMEOUT,
+ AnytimeStatsUpdateTimeoutHandler);
+ enable_timeout_after(ANYTIME_STATS_UPDATE_TIMEOUT, PGSTAT_ANYTIME_FLUSH_INTERVAL);
}
/*
@@ -1446,3 +1450,14 @@ ThereIsAtLeastOneRole(void)
return result;
}
+
+/*
+ * Timeout handler for flushing non-transactional stats.
+ */
+static void
+AnytimeStatsUpdateTimeoutHandler(void)
+{
+ AnytimeStatsUpdateTimeoutPending = true;
+ InterruptPending = true;
+ SetLatch(MyLatch);
+}
diff --git a/src/include/miscadmin.h b/src/include/miscadmin.h
index db559b39c4d..8aeb9628871 100644
--- a/src/include/miscadmin.h
+++ b/src/include/miscadmin.h
@@ -96,6 +96,7 @@ extern PGDLLIMPORT volatile sig_atomic_t IdleSessionTimeoutPending;
extern PGDLLIMPORT volatile sig_atomic_t ProcSignalBarrierPending;
extern PGDLLIMPORT volatile sig_atomic_t LogMemoryContextPending;
extern PGDLLIMPORT volatile sig_atomic_t IdleStatsUpdateTimeoutPending;
+extern PGDLLIMPORT volatile sig_atomic_t AnytimeStatsUpdateTimeoutPending;
extern PGDLLIMPORT volatile sig_atomic_t CheckClientConnectionPending;
extern PGDLLIMPORT volatile sig_atomic_t ClientConnectionLost;
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index fff7ecc2533..86e65397614 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -35,6 +35,9 @@
/* Default directory to store temporary statistics data in */
#define PG_STAT_TMP_DIR "pg_stat_tmp"
+/* When to call pgstat_report_anytime_stat() again */
+#define PGSTAT_ANYTIME_FLUSH_INTERVAL 1000
+
/* Values for track_functions GUC variable --- order is significant! */
typedef enum TrackFunctionsLevel
{
@@ -533,6 +536,7 @@ extern void pgstat_initialize(void);
/* Functions called from backends */
extern long pgstat_report_stat(bool force);
+extern void pgstat_report_anytime_stat(bool force);
extern void pgstat_force_next_flush(void);
extern void pgstat_reset_counters(void);
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 9b8fbae00ed..63feae640d1 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -224,6 +224,16 @@ typedef struct PgStat_SubXactStatus
PgStat_TableXactStatus *first; /* head of list for this subxact */
} PgStat_SubXactStatus;
+/*
+ * Flush behavior for statistics kinds.
+ */
+typedef enum PgStat_FlushBehavior
+{
+ FLUSH_ANYTIME, /* All fields can be flushed anytime,
+ * including within transactions */
+ FLUSH_AT_TXN_BOUNDARY, /* All fields can only be flushed at
+ * transaction boundary */
+} PgStat_FlushBehavior;
/*
* Metadata for a specific kind of statistics.
@@ -251,6 +261,9 @@ typedef struct PgStat_KindInfo
*/
bool track_entry_count:1;
+ /* Flush behavior */
+ PgStat_FlushBehavior flush_behavior;
+
/*
* The size of an entry in the shared stats hash table (pointed to by
* PgStatShared_HashEntry->body). For fixed-numbered statistics, this is
diff --git a/src/include/utils/timeout.h b/src/include/utils/timeout.h
index 0965b590b34..10723bb664c 100644
--- a/src/include/utils/timeout.h
+++ b/src/include/utils/timeout.h
@@ -35,6 +35,7 @@ typedef enum TimeoutId
IDLE_SESSION_TIMEOUT,
IDLE_STATS_UPDATE_TIMEOUT,
CLIENT_CONNECTION_CHECK_TIMEOUT,
+ ANYTIME_STATS_UPDATE_TIMEOUT,
STARTUP_PROGRESS_TIMEOUT,
/* First user-definable timeout reason */
USER_TIMEOUT,
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 3f3a888fd0e..610b35a9b31 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -2268,6 +2268,7 @@ PgStat_Counter
PgStat_EntryRef
PgStat_EntryRefHashEntry
PgStat_FetchConsistency
+PgStat_FlushBehavior
PgStat_FunctionCallUsage
PgStat_FunctionCounts
PgStat_HashKey
--
2.34.1
--OFsrIl+bjhifp5hk
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v2-0002-Remove-useless-calls-to-flush-some-stats.patch"
^ permalink raw reply [nested|flat] 12+ messages in thread
* [PATCH v3 1/3] Add pgstat_report_anytime_stat() for periodic stats flushing
@ 2026-01-05 09:41 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 12+ messages in thread
From: Bertrand Drouvot @ 2026-01-05 09:41 UTC (permalink / raw)
Long running transactions can accumulate significant statistics (WAL, IO, ...)
that remain unflushed until the transaction ends. This delays visibility of
resource usage in monitoring views like pg_stat_io and pg_stat_wal.
This commit introduces pgstat_report_anytime_stat(), which flushes
non transactional statistics even inside active transactions. A new timeout
handler fires every second to call this function, ensuring timely stats visibility
without waiting for transaction completion.
Implementation details:
- Add PgStat_FlushMode enum to classify stats kinds:
* FLUSH_ANYTIME: Stats that can always be flushed (WAL, IO, ...)
* FLUSH_AT_TXN_BOUNDARY: Stats requiring transaction boundaries
- Modify pgstat_flush_pending_entries() and pgstat_flush_fixed_stats()
to accept a boolean anytime_only parameter:
* When false: flushes all stats (existing behavior)
* When true: flushes only FLUSH_ANYTIME stats and skips FLUSH_AT_TXN_BOUNDARY stats
- This relies on the existing PGSTAT_MIN_INTERVAL to fire every 1 second, calling
pgstat_report_anytime_stat(false)
The force parameter in pgstat_report_anytime_stat() is currently unused (always
called with force=false) but reserved for future use cases requiring immediate
flushing.
---
src/backend/tcop/postgres.c | 16 ++++
src/backend/utils/activity/pgstat.c | 111 +++++++++++++++++++++++-----
src/backend/utils/init/globals.c | 1 +
src/backend/utils/init/postinit.c | 15 ++++
src/include/miscadmin.h | 1 +
src/include/pgstat.h | 4 +
src/include/utils/pgstat_internal.h | 16 ++++
src/include/utils/timeout.h | 1 +
src/tools/pgindent/typedefs.list | 1 +
9 files changed, 148 insertions(+), 18 deletions(-)
8.1% src/backend/tcop/
68.4% src/backend/utils/activity/
9.6% src/backend/utils/init/
9.2% src/include/utils/
4.1% src/include/
diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c
index e54bf1e760f..132fae61423 100644
--- a/src/backend/tcop/postgres.c
+++ b/src/backend/tcop/postgres.c
@@ -3530,6 +3530,22 @@ ProcessInterrupts(void)
pgstat_report_stat(true);
}
+ /*
+ * Flush stats outside of transaction boundary if the timeout fired.
+ * Unlike transactional stats, these can be flushed even inside a running
+ * transaction.
+ */
+ if (AnytimeStatsUpdateTimeoutPending)
+ {
+ AnytimeStatsUpdateTimeoutPending = false;
+
+ pgstat_report_anytime_stat(false);
+
+ /* Schedule next timeout */
+ enable_timeout_after(ANYTIME_STATS_UPDATE_TIMEOUT,
+ PGSTAT_MIN_INTERVAL);
+ }
+
if (ProcSignalBarrierPending)
ProcessProcSignalBarrier();
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index 11bb71cad5a..ab4d9088a9a 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -122,8 +122,6 @@
* ----------
*/
-/* minimum interval non-forced stats flushes.*/
-#define PGSTAT_MIN_INTERVAL 1000
/* how long until to block flushing pending stats updates */
#define PGSTAT_MAX_INTERVAL 60000
/* when to call pgstat_report_stat() again, even when idle */
@@ -187,7 +185,8 @@ static void pgstat_init_snapshot_fixed(void);
static void pgstat_reset_after_failure(void);
-static bool pgstat_flush_pending_entries(bool nowait);
+static bool pgstat_flush_pending_entries(bool nowait, bool anytime_only);
+static bool pgstat_flush_fixed_stats(bool nowait, bool anytime_only);
static void pgstat_prep_snapshot(void);
static void pgstat_build_snapshot(void);
@@ -288,6 +287,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = true,
+ .flush_mode = FLUSH_AT_TXN_BOUNDARY,
/* so pg_stat_database entries can be seen in all databases */
.accessed_across_databases = true,
@@ -305,6 +305,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = true,
+ .flush_mode = FLUSH_AT_TXN_BOUNDARY,
.shared_size = sizeof(PgStatShared_Relation),
.shared_data_off = offsetof(PgStatShared_Relation, stats),
@@ -321,6 +322,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = true,
+ .flush_mode = FLUSH_AT_TXN_BOUNDARY,
.shared_size = sizeof(PgStatShared_Function),
.shared_data_off = offsetof(PgStatShared_Function, stats),
@@ -336,6 +338,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = true,
+ .flush_mode = FLUSH_AT_TXN_BOUNDARY,
.accessed_across_databases = true,
@@ -353,6 +356,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = true,
+ .flush_mode = FLUSH_AT_TXN_BOUNDARY,
/* so pg_stat_subscription_stats entries can be seen in all databases */
.accessed_across_databases = true,
@@ -370,6 +374,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = false,
+ .flush_mode = FLUSH_ANYTIME,
.accessed_across_databases = true,
@@ -388,6 +393,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = true,
.write_to_file = true,
+ .flush_mode = FLUSH_ANYTIME,
.snapshot_ctl_off = offsetof(PgStat_Snapshot, archiver),
.shared_ctl_off = offsetof(PgStat_ShmemControl, archiver),
@@ -404,6 +410,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = true,
.write_to_file = true,
+ .flush_mode = FLUSH_ANYTIME,
.snapshot_ctl_off = offsetof(PgStat_Snapshot, bgwriter),
.shared_ctl_off = offsetof(PgStat_ShmemControl, bgwriter),
@@ -420,6 +427,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = true,
.write_to_file = true,
+ .flush_mode = FLUSH_ANYTIME,
.snapshot_ctl_off = offsetof(PgStat_Snapshot, checkpointer),
.shared_ctl_off = offsetof(PgStat_ShmemControl, checkpointer),
@@ -436,6 +444,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = true,
.write_to_file = true,
+ .flush_mode = FLUSH_ANYTIME,
.snapshot_ctl_off = offsetof(PgStat_Snapshot, io),
.shared_ctl_off = offsetof(PgStat_ShmemControl, io),
@@ -453,6 +462,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = true,
.write_to_file = true,
+ .flush_mode = FLUSH_ANYTIME,
.snapshot_ctl_off = offsetof(PgStat_Snapshot, slru),
.shared_ctl_off = offsetof(PgStat_ShmemControl, slru),
@@ -470,6 +480,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = true,
.write_to_file = true,
+ .flush_mode = FLUSH_ANYTIME,
.snapshot_ctl_off = offsetof(PgStat_Snapshot, wal),
.shared_ctl_off = offsetof(PgStat_ShmemControl, wal),
@@ -775,23 +786,11 @@ pgstat_report_stat(bool force)
partial_flush = false;
/* flush of variable-numbered stats tracked in pending entries list */
- partial_flush |= pgstat_flush_pending_entries(nowait);
+ partial_flush |= pgstat_flush_pending_entries(nowait, false);
/* flush of other stats kinds */
if (pgstat_report_fixed)
- {
- for (PgStat_Kind kind = PGSTAT_KIND_MIN; kind <= PGSTAT_KIND_MAX; kind++)
- {
- const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
-
- if (!kind_info)
- continue;
- if (!kind_info->flush_static_cb)
- continue;
-
- partial_flush |= kind_info->flush_static_cb(nowait);
- }
- }
+ partial_flush |= pgstat_flush_fixed_stats(nowait, false);
last_flush = now;
@@ -1345,9 +1344,14 @@ pgstat_delete_pending_entry(PgStat_EntryRef *entry_ref)
/*
* Flush out pending variable-numbered stats.
+ *
+ * If anytime_only is true, only flushes FLUSH_ANYTIME entries.
+ * This is safe to call inside transactions.
+ *
+ * If anytime_only is false, flushes all entries.
*/
static bool
-pgstat_flush_pending_entries(bool nowait)
+pgstat_flush_pending_entries(bool nowait, bool anytime_only)
{
bool have_pending = false;
dlist_node *cur = NULL;
@@ -1377,6 +1381,20 @@ pgstat_flush_pending_entries(bool nowait)
Assert(!kind_info->fixed_amount);
Assert(kind_info->flush_pending_cb != NULL);
+ /* Skip transactional stats if we're in anytime_only mode */
+ if (anytime_only && kind_info->flush_mode == FLUSH_AT_TXN_BOUNDARY)
+ {
+ have_pending = true;
+
+ if (dlist_has_next(&pgStatPending, cur))
+ next = dlist_next_node(&pgStatPending, cur);
+ else
+ next = NULL;
+
+ cur = next;
+ continue;
+ }
+
/* flush the stats, if possible */
did_flush = kind_info->flush_pending_cb(entry_ref, nowait);
@@ -1402,6 +1420,33 @@ pgstat_flush_pending_entries(bool nowait)
return have_pending;
}
+/*
+ * Flush fixed-amount stats.
+ *
+ * If anytime_only is true, only flushes FLUSH_ANYTIME stats (safe inside transactions).
+ * If anytime_only is false, flushes all stats with flush_static_cb.
+ */
+static bool
+pgstat_flush_fixed_stats(bool nowait, bool anytime_only)
+{
+ bool partial_flush = false;
+
+ for (PgStat_Kind kind = PGSTAT_KIND_MIN; kind <= PGSTAT_KIND_MAX; kind++)
+ {
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (!kind_info || !kind_info->flush_static_cb)
+ continue;
+
+ /* Skip transactional stats if we're in anytime_only mode */
+ if (anytime_only && kind_info->flush_mode == FLUSH_AT_TXN_BOUNDARY)
+ continue;
+
+ partial_flush |= kind_info->flush_static_cb(nowait);
+ }
+
+ return partial_flush;
+}
/* ------------------------------------------------------------
* Helper / infrastructure functions
@@ -2119,3 +2164,33 @@ assign_stats_fetch_consistency(int newval, void *extra)
if (pgstat_fetch_consistency != newval)
force_stats_snapshot_clear = true;
}
+
+/*
+ * Flushes only FLUSH_ANYTIME stats using non-blocking locks. Transactional
+ * stats (FLUSH_AT_TXN_BOUNDARY) remain pending until transaction boundary.
+ * Safe to call inside transactions.
+ */
+void
+pgstat_report_anytime_stat(bool force)
+{
+ bool nowait = !force;
+
+ pgstat_assert_is_up();
+
+ /*
+ * Exit if no pending stats at all. This avoids unnecessary work when
+ * backends are idle or in sessions without stats accumulation.
+ *
+ * Note: This check isn't precise as there might be only transactional
+ * stats pending, which we'll skip during the flush. However, maintaining
+ * precise tracking would add complexity that does not seem worth it from
+ * a performance point of view (no noticeable performance regression has
+ * been observed with the current implementation).
+ */
+ if (dlist_is_empty(&pgStatPending) && !pgstat_report_fixed)
+ return;
+
+ /* Flush stats outside of transaction boundary */
+ pgstat_flush_pending_entries(nowait, true);
+ pgstat_flush_fixed_stats(nowait, true);
+}
diff --git a/src/backend/utils/init/globals.c b/src/backend/utils/init/globals.c
index 36ad708b360..ad44826c39e 100644
--- a/src/backend/utils/init/globals.c
+++ b/src/backend/utils/init/globals.c
@@ -40,6 +40,7 @@ volatile sig_atomic_t IdleSessionTimeoutPending = false;
volatile sig_atomic_t ProcSignalBarrierPending = false;
volatile sig_atomic_t LogMemoryContextPending = false;
volatile sig_atomic_t IdleStatsUpdateTimeoutPending = false;
+volatile sig_atomic_t AnytimeStatsUpdateTimeoutPending = false;
volatile uint32 InterruptHoldoffCount = 0;
volatile uint32 QueryCancelHoldoffCount = 0;
volatile uint32 CritSectionCount = 0;
diff --git a/src/backend/utils/init/postinit.c b/src/backend/utils/init/postinit.c
index 3f401faf3de..6076f531c4a 100644
--- a/src/backend/utils/init/postinit.c
+++ b/src/backend/utils/init/postinit.c
@@ -82,6 +82,7 @@ static void TransactionTimeoutHandler(void);
static void IdleSessionTimeoutHandler(void);
static void IdleStatsUpdateTimeoutHandler(void);
static void ClientCheckTimeoutHandler(void);
+static void AnytimeStatsUpdateTimeoutHandler(void);
static bool ThereIsAtLeastOneRole(void);
static void process_startup_options(Port *port, bool am_superuser);
static void process_settings(Oid databaseid, Oid roleid);
@@ -765,6 +766,9 @@ InitPostgres(const char *in_dbname, Oid dboid,
RegisterTimeout(CLIENT_CONNECTION_CHECK_TIMEOUT, ClientCheckTimeoutHandler);
RegisterTimeout(IDLE_STATS_UPDATE_TIMEOUT,
IdleStatsUpdateTimeoutHandler);
+ RegisterTimeout(ANYTIME_STATS_UPDATE_TIMEOUT,
+ AnytimeStatsUpdateTimeoutHandler);
+ enable_timeout_after(ANYTIME_STATS_UPDATE_TIMEOUT, PGSTAT_MIN_INTERVAL);
}
/*
@@ -1446,3 +1450,14 @@ ThereIsAtLeastOneRole(void)
return result;
}
+
+/*
+ * Timeout handler for flushing non-transactional stats.
+ */
+static void
+AnytimeStatsUpdateTimeoutHandler(void)
+{
+ AnytimeStatsUpdateTimeoutPending = true;
+ InterruptPending = true;
+ SetLatch(MyLatch);
+}
diff --git a/src/include/miscadmin.h b/src/include/miscadmin.h
index db559b39c4d..8aeb9628871 100644
--- a/src/include/miscadmin.h
+++ b/src/include/miscadmin.h
@@ -96,6 +96,7 @@ extern PGDLLIMPORT volatile sig_atomic_t IdleSessionTimeoutPending;
extern PGDLLIMPORT volatile sig_atomic_t ProcSignalBarrierPending;
extern PGDLLIMPORT volatile sig_atomic_t LogMemoryContextPending;
extern PGDLLIMPORT volatile sig_atomic_t IdleStatsUpdateTimeoutPending;
+extern PGDLLIMPORT volatile sig_atomic_t AnytimeStatsUpdateTimeoutPending;
extern PGDLLIMPORT volatile sig_atomic_t CheckClientConnectionPending;
extern PGDLLIMPORT volatile sig_atomic_t ClientConnectionLost;
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index fff7ecc2533..1651f16f966 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -35,6 +35,9 @@
/* Default directory to store temporary statistics data in */
#define PG_STAT_TMP_DIR "pg_stat_tmp"
+/* Minimum interval non-forced stats flushes */
+#define PGSTAT_MIN_INTERVAL 1000
+
/* Values for track_functions GUC variable --- order is significant! */
typedef enum TrackFunctionsLevel
{
@@ -533,6 +536,7 @@ extern void pgstat_initialize(void);
/* Functions called from backends */
extern long pgstat_report_stat(bool force);
+extern void pgstat_report_anytime_stat(bool force);
extern void pgstat_force_next_flush(void);
extern void pgstat_reset_counters(void);
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 9b8fbae00ed..46ce90c9624 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -224,6 +224,19 @@ typedef struct PgStat_SubXactStatus
PgStat_TableXactStatus *first; /* head of list for this subxact */
} PgStat_SubXactStatus;
+/*
+ * Flush mode for statistics kinds.
+ *
+ * FLUSH_AT_TXN_BOUNDARY has to be the first because we want it to be the
+ * default value.
+ */
+typedef enum PgStat_FlushMode
+{
+ FLUSH_AT_TXN_BOUNDARY, /* All fields can only be flushed at
+ * transaction boundary */
+ FLUSH_ANYTIME, /* All fields can be flushed anytime,
+ * including within transactions */
+} PgStat_FlushMode;
/*
* Metadata for a specific kind of statistics.
@@ -251,6 +264,9 @@ typedef struct PgStat_KindInfo
*/
bool track_entry_count:1;
+ /* Flush mode */
+ PgStat_FlushMode flush_mode;
+
/*
* The size of an entry in the shared stats hash table (pointed to by
* PgStatShared_HashEntry->body). For fixed-numbered statistics, this is
diff --git a/src/include/utils/timeout.h b/src/include/utils/timeout.h
index 0965b590b34..10723bb664c 100644
--- a/src/include/utils/timeout.h
+++ b/src/include/utils/timeout.h
@@ -35,6 +35,7 @@ typedef enum TimeoutId
IDLE_SESSION_TIMEOUT,
IDLE_STATS_UPDATE_TIMEOUT,
CLIENT_CONNECTION_CHECK_TIMEOUT,
+ ANYTIME_STATS_UPDATE_TIMEOUT,
STARTUP_PROGRESS_TIMEOUT,
/* First user-definable timeout reason */
USER_TIMEOUT,
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 3f3a888fd0e..d3912b43fdc 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -2268,6 +2268,7 @@ PgStat_Counter
PgStat_EntryRef
PgStat_EntryRefHashEntry
PgStat_FetchConsistency
+PgStat_FlushMode
PgStat_FunctionCallUsage
PgStat_FunctionCounts
PgStat_HashKey
--
2.34.1
--lCc1MWfC7i2uqs8g
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v3-0002-Remove-useless-calls-to-flush-some-stats.patch"
^ permalink raw reply [nested|flat] 12+ messages in thread
* [PATCH v4 1/4] Add pgstat_report_anytime_stat() for periodic stats flushing
@ 2026-01-05 09:41 Bertrand Drouvot <[email protected]>
0 siblings, 0 replies; 12+ messages in thread
From: Bertrand Drouvot @ 2026-01-05 09:41 UTC (permalink / raw)
Long running transactions can accumulate significant statistics (WAL, IO, ...)
that remain unflushed until the transaction ends. This delays visibility of
resource usage in monitoring views like pg_stat_io and pg_stat_wal.
This commit introduces pgstat_report_anytime_stat(), which flushes
non transactional statistics even inside active transactions. A new timeout
handler fires every second to call this function, ensuring timely stats visibility
without waiting for transaction completion.
Implementation details:
- Add PgStat_FlushMode enum to classify stats kinds:
* FLUSH_ANYTIME: Stats that can always be flushed (WAL, IO, ...)
* FLUSH_AT_TXN_BOUNDARY: Stats requiring transaction boundaries
- Modify pgstat_flush_pending_entries() and pgstat_flush_fixed_stats()
to accept a boolean anytime_only parameter:
* When false: flushes all stats (existing behavior)
* When true: flushes only FLUSH_ANYTIME stats and skips FLUSH_AT_TXN_BOUNDARY stats
- This relies on the existing PGSTAT_MIN_INTERVAL to fire every 1 second, calling
pgstat_report_anytime_stat(false)
The force parameter in pgstat_report_anytime_stat() is currently unused (always
called with force=false) but reserved for future use cases requiring immediate
flushing.
---
src/backend/storage/lmgr/proc.c | 10 +++
src/backend/tcop/postgres.c | 16 ++++
src/backend/utils/activity/pgstat.c | 111 +++++++++++++++++++++++-----
src/backend/utils/init/globals.c | 1 +
src/backend/utils/init/postinit.c | 15 ++++
src/include/miscadmin.h | 1 +
src/include/pgstat.h | 4 +
src/include/utils/pgstat_internal.h | 20 +++++
src/include/utils/timeout.h | 1 +
src/tools/pgindent/typedefs.list | 1 +
10 files changed, 162 insertions(+), 18 deletions(-)
7.0% src/backend/storage/lmgr/
7.3% src/backend/tcop/
61.1% src/backend/utils/activity/
8.6% src/backend/utils/init/
11.8% src/include/utils/
3.6% src/include/
diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c
index 063826ae576..012705a2ee6 100644
--- a/src/backend/storage/lmgr/proc.c
+++ b/src/backend/storage/lmgr/proc.c
@@ -1322,6 +1322,7 @@ ProcSleep(LOCALLOCK *locallock)
bool allow_autovacuum_cancel = true;
bool logged_recovery_conflict = false;
ProcWaitStatus myWaitStatus;
+ bool anytime_timeout_was_active = false;
/* The caller must've armed the on-error cleanup mechanism */
Assert(GetAwaitedLock() == locallock);
@@ -1398,6 +1399,12 @@ ProcSleep(LOCALLOCK *locallock)
standbyWaitStart = GetCurrentTimestamp();
}
+ anytime_timeout_was_active = get_timeout_active(ANYTIME_STATS_UPDATE_TIMEOUT);
+
+ /* No need to try to flush the statistics while the process is sleeping */
+ if (anytime_timeout_was_active)
+ disable_timeout(ANYTIME_STATS_UPDATE_TIMEOUT, false);
+
/*
* If somebody wakes us between LWLockRelease and WaitLatch, the latch
* will not wait. But a set latch does not necessarily mean that the lock
@@ -1661,6 +1668,9 @@ ProcSleep(LOCALLOCK *locallock)
}
} while (myWaitStatus == PROC_WAIT_STATUS_WAITING);
+ if (anytime_timeout_was_active)
+ enable_timeout_after(ANYTIME_STATS_UPDATE_TIMEOUT, PGSTAT_MIN_INTERVAL);
+
/*
* Disable the timers, if they are still running. As in LockErrorCleanup,
* we must preserve the LOCK_TIMEOUT indicator flag: if a lock timeout has
diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c
index e54bf1e760f..132fae61423 100644
--- a/src/backend/tcop/postgres.c
+++ b/src/backend/tcop/postgres.c
@@ -3530,6 +3530,22 @@ ProcessInterrupts(void)
pgstat_report_stat(true);
}
+ /*
+ * Flush stats outside of transaction boundary if the timeout fired.
+ * Unlike transactional stats, these can be flushed even inside a running
+ * transaction.
+ */
+ if (AnytimeStatsUpdateTimeoutPending)
+ {
+ AnytimeStatsUpdateTimeoutPending = false;
+
+ pgstat_report_anytime_stat(false);
+
+ /* Schedule next timeout */
+ enable_timeout_after(ANYTIME_STATS_UPDATE_TIMEOUT,
+ PGSTAT_MIN_INTERVAL);
+ }
+
if (ProcSignalBarrierPending)
ProcessProcSignalBarrier();
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index 11bb71cad5a..ab4d9088a9a 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -122,8 +122,6 @@
* ----------
*/
-/* minimum interval non-forced stats flushes.*/
-#define PGSTAT_MIN_INTERVAL 1000
/* how long until to block flushing pending stats updates */
#define PGSTAT_MAX_INTERVAL 60000
/* when to call pgstat_report_stat() again, even when idle */
@@ -187,7 +185,8 @@ static void pgstat_init_snapshot_fixed(void);
static void pgstat_reset_after_failure(void);
-static bool pgstat_flush_pending_entries(bool nowait);
+static bool pgstat_flush_pending_entries(bool nowait, bool anytime_only);
+static bool pgstat_flush_fixed_stats(bool nowait, bool anytime_only);
static void pgstat_prep_snapshot(void);
static void pgstat_build_snapshot(void);
@@ -288,6 +287,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = true,
+ .flush_mode = FLUSH_AT_TXN_BOUNDARY,
/* so pg_stat_database entries can be seen in all databases */
.accessed_across_databases = true,
@@ -305,6 +305,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = true,
+ .flush_mode = FLUSH_AT_TXN_BOUNDARY,
.shared_size = sizeof(PgStatShared_Relation),
.shared_data_off = offsetof(PgStatShared_Relation, stats),
@@ -321,6 +322,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = true,
+ .flush_mode = FLUSH_AT_TXN_BOUNDARY,
.shared_size = sizeof(PgStatShared_Function),
.shared_data_off = offsetof(PgStatShared_Function, stats),
@@ -336,6 +338,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = true,
+ .flush_mode = FLUSH_AT_TXN_BOUNDARY,
.accessed_across_databases = true,
@@ -353,6 +356,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = true,
+ .flush_mode = FLUSH_AT_TXN_BOUNDARY,
/* so pg_stat_subscription_stats entries can be seen in all databases */
.accessed_across_databases = true,
@@ -370,6 +374,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = false,
.write_to_file = false,
+ .flush_mode = FLUSH_ANYTIME,
.accessed_across_databases = true,
@@ -388,6 +393,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = true,
.write_to_file = true,
+ .flush_mode = FLUSH_ANYTIME,
.snapshot_ctl_off = offsetof(PgStat_Snapshot, archiver),
.shared_ctl_off = offsetof(PgStat_ShmemControl, archiver),
@@ -404,6 +410,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = true,
.write_to_file = true,
+ .flush_mode = FLUSH_ANYTIME,
.snapshot_ctl_off = offsetof(PgStat_Snapshot, bgwriter),
.shared_ctl_off = offsetof(PgStat_ShmemControl, bgwriter),
@@ -420,6 +427,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = true,
.write_to_file = true,
+ .flush_mode = FLUSH_ANYTIME,
.snapshot_ctl_off = offsetof(PgStat_Snapshot, checkpointer),
.shared_ctl_off = offsetof(PgStat_ShmemControl, checkpointer),
@@ -436,6 +444,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = true,
.write_to_file = true,
+ .flush_mode = FLUSH_ANYTIME,
.snapshot_ctl_off = offsetof(PgStat_Snapshot, io),
.shared_ctl_off = offsetof(PgStat_ShmemControl, io),
@@ -453,6 +462,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = true,
.write_to_file = true,
+ .flush_mode = FLUSH_ANYTIME,
.snapshot_ctl_off = offsetof(PgStat_Snapshot, slru),
.shared_ctl_off = offsetof(PgStat_ShmemControl, slru),
@@ -470,6 +480,7 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE]
.fixed_amount = true,
.write_to_file = true,
+ .flush_mode = FLUSH_ANYTIME,
.snapshot_ctl_off = offsetof(PgStat_Snapshot, wal),
.shared_ctl_off = offsetof(PgStat_ShmemControl, wal),
@@ -775,23 +786,11 @@ pgstat_report_stat(bool force)
partial_flush = false;
/* flush of variable-numbered stats tracked in pending entries list */
- partial_flush |= pgstat_flush_pending_entries(nowait);
+ partial_flush |= pgstat_flush_pending_entries(nowait, false);
/* flush of other stats kinds */
if (pgstat_report_fixed)
- {
- for (PgStat_Kind kind = PGSTAT_KIND_MIN; kind <= PGSTAT_KIND_MAX; kind++)
- {
- const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
-
- if (!kind_info)
- continue;
- if (!kind_info->flush_static_cb)
- continue;
-
- partial_flush |= kind_info->flush_static_cb(nowait);
- }
- }
+ partial_flush |= pgstat_flush_fixed_stats(nowait, false);
last_flush = now;
@@ -1345,9 +1344,14 @@ pgstat_delete_pending_entry(PgStat_EntryRef *entry_ref)
/*
* Flush out pending variable-numbered stats.
+ *
+ * If anytime_only is true, only flushes FLUSH_ANYTIME entries.
+ * This is safe to call inside transactions.
+ *
+ * If anytime_only is false, flushes all entries.
*/
static bool
-pgstat_flush_pending_entries(bool nowait)
+pgstat_flush_pending_entries(bool nowait, bool anytime_only)
{
bool have_pending = false;
dlist_node *cur = NULL;
@@ -1377,6 +1381,20 @@ pgstat_flush_pending_entries(bool nowait)
Assert(!kind_info->fixed_amount);
Assert(kind_info->flush_pending_cb != NULL);
+ /* Skip transactional stats if we're in anytime_only mode */
+ if (anytime_only && kind_info->flush_mode == FLUSH_AT_TXN_BOUNDARY)
+ {
+ have_pending = true;
+
+ if (dlist_has_next(&pgStatPending, cur))
+ next = dlist_next_node(&pgStatPending, cur);
+ else
+ next = NULL;
+
+ cur = next;
+ continue;
+ }
+
/* flush the stats, if possible */
did_flush = kind_info->flush_pending_cb(entry_ref, nowait);
@@ -1402,6 +1420,33 @@ pgstat_flush_pending_entries(bool nowait)
return have_pending;
}
+/*
+ * Flush fixed-amount stats.
+ *
+ * If anytime_only is true, only flushes FLUSH_ANYTIME stats (safe inside transactions).
+ * If anytime_only is false, flushes all stats with flush_static_cb.
+ */
+static bool
+pgstat_flush_fixed_stats(bool nowait, bool anytime_only)
+{
+ bool partial_flush = false;
+
+ for (PgStat_Kind kind = PGSTAT_KIND_MIN; kind <= PGSTAT_KIND_MAX; kind++)
+ {
+ const PgStat_KindInfo *kind_info = pgstat_get_kind_info(kind);
+
+ if (!kind_info || !kind_info->flush_static_cb)
+ continue;
+
+ /* Skip transactional stats if we're in anytime_only mode */
+ if (anytime_only && kind_info->flush_mode == FLUSH_AT_TXN_BOUNDARY)
+ continue;
+
+ partial_flush |= kind_info->flush_static_cb(nowait);
+ }
+
+ return partial_flush;
+}
/* ------------------------------------------------------------
* Helper / infrastructure functions
@@ -2119,3 +2164,33 @@ assign_stats_fetch_consistency(int newval, void *extra)
if (pgstat_fetch_consistency != newval)
force_stats_snapshot_clear = true;
}
+
+/*
+ * Flushes only FLUSH_ANYTIME stats using non-blocking locks. Transactional
+ * stats (FLUSH_AT_TXN_BOUNDARY) remain pending until transaction boundary.
+ * Safe to call inside transactions.
+ */
+void
+pgstat_report_anytime_stat(bool force)
+{
+ bool nowait = !force;
+
+ pgstat_assert_is_up();
+
+ /*
+ * Exit if no pending stats at all. This avoids unnecessary work when
+ * backends are idle or in sessions without stats accumulation.
+ *
+ * Note: This check isn't precise as there might be only transactional
+ * stats pending, which we'll skip during the flush. However, maintaining
+ * precise tracking would add complexity that does not seem worth it from
+ * a performance point of view (no noticeable performance regression has
+ * been observed with the current implementation).
+ */
+ if (dlist_is_empty(&pgStatPending) && !pgstat_report_fixed)
+ return;
+
+ /* Flush stats outside of transaction boundary */
+ pgstat_flush_pending_entries(nowait, true);
+ pgstat_flush_fixed_stats(nowait, true);
+}
diff --git a/src/backend/utils/init/globals.c b/src/backend/utils/init/globals.c
index 36ad708b360..ad44826c39e 100644
--- a/src/backend/utils/init/globals.c
+++ b/src/backend/utils/init/globals.c
@@ -40,6 +40,7 @@ volatile sig_atomic_t IdleSessionTimeoutPending = false;
volatile sig_atomic_t ProcSignalBarrierPending = false;
volatile sig_atomic_t LogMemoryContextPending = false;
volatile sig_atomic_t IdleStatsUpdateTimeoutPending = false;
+volatile sig_atomic_t AnytimeStatsUpdateTimeoutPending = false;
volatile uint32 InterruptHoldoffCount = 0;
volatile uint32 QueryCancelHoldoffCount = 0;
volatile uint32 CritSectionCount = 0;
diff --git a/src/backend/utils/init/postinit.c b/src/backend/utils/init/postinit.c
index 3f401faf3de..6076f531c4a 100644
--- a/src/backend/utils/init/postinit.c
+++ b/src/backend/utils/init/postinit.c
@@ -82,6 +82,7 @@ static void TransactionTimeoutHandler(void);
static void IdleSessionTimeoutHandler(void);
static void IdleStatsUpdateTimeoutHandler(void);
static void ClientCheckTimeoutHandler(void);
+static void AnytimeStatsUpdateTimeoutHandler(void);
static bool ThereIsAtLeastOneRole(void);
static void process_startup_options(Port *port, bool am_superuser);
static void process_settings(Oid databaseid, Oid roleid);
@@ -765,6 +766,9 @@ InitPostgres(const char *in_dbname, Oid dboid,
RegisterTimeout(CLIENT_CONNECTION_CHECK_TIMEOUT, ClientCheckTimeoutHandler);
RegisterTimeout(IDLE_STATS_UPDATE_TIMEOUT,
IdleStatsUpdateTimeoutHandler);
+ RegisterTimeout(ANYTIME_STATS_UPDATE_TIMEOUT,
+ AnytimeStatsUpdateTimeoutHandler);
+ enable_timeout_after(ANYTIME_STATS_UPDATE_TIMEOUT, PGSTAT_MIN_INTERVAL);
}
/*
@@ -1446,3 +1450,14 @@ ThereIsAtLeastOneRole(void)
return result;
}
+
+/*
+ * Timeout handler for flushing non-transactional stats.
+ */
+static void
+AnytimeStatsUpdateTimeoutHandler(void)
+{
+ AnytimeStatsUpdateTimeoutPending = true;
+ InterruptPending = true;
+ SetLatch(MyLatch);
+}
diff --git a/src/include/miscadmin.h b/src/include/miscadmin.h
index db559b39c4d..8aeb9628871 100644
--- a/src/include/miscadmin.h
+++ b/src/include/miscadmin.h
@@ -96,6 +96,7 @@ extern PGDLLIMPORT volatile sig_atomic_t IdleSessionTimeoutPending;
extern PGDLLIMPORT volatile sig_atomic_t ProcSignalBarrierPending;
extern PGDLLIMPORT volatile sig_atomic_t LogMemoryContextPending;
extern PGDLLIMPORT volatile sig_atomic_t IdleStatsUpdateTimeoutPending;
+extern PGDLLIMPORT volatile sig_atomic_t AnytimeStatsUpdateTimeoutPending;
extern PGDLLIMPORT volatile sig_atomic_t CheckClientConnectionPending;
extern PGDLLIMPORT volatile sig_atomic_t ClientConnectionLost;
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index fff7ecc2533..1651f16f966 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -35,6 +35,9 @@
/* Default directory to store temporary statistics data in */
#define PG_STAT_TMP_DIR "pg_stat_tmp"
+/* Minimum interval non-forced stats flushes */
+#define PGSTAT_MIN_INTERVAL 1000
+
/* Values for track_functions GUC variable --- order is significant! */
typedef enum TrackFunctionsLevel
{
@@ -533,6 +536,7 @@ extern void pgstat_initialize(void);
/* Functions called from backends */
extern long pgstat_report_stat(bool force);
+extern void pgstat_report_anytime_stat(bool force);
extern void pgstat_force_next_flush(void);
extern void pgstat_reset_counters(void);
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index 9b8fbae00ed..9ca39ea9a9a 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -224,6 +224,19 @@ typedef struct PgStat_SubXactStatus
PgStat_TableXactStatus *first; /* head of list for this subxact */
} PgStat_SubXactStatus;
+/*
+ * Flush mode for statistics kinds.
+ *
+ * FLUSH_AT_TXN_BOUNDARY has to be the first because we want it to be the
+ * default value.
+ */
+typedef enum PgStat_FlushMode
+{
+ FLUSH_AT_TXN_BOUNDARY, /* All fields can only be flushed at
+ * transaction boundary */
+ FLUSH_ANYTIME, /* All fields can be flushed anytime,
+ * including within transactions */
+} PgStat_FlushMode;
/*
* Metadata for a specific kind of statistics.
@@ -251,6 +264,13 @@ typedef struct PgStat_KindInfo
*/
bool track_entry_count:1;
+ /*
+ * Some stats have to be updated only at transaction boundaries (such as
+ * tuples_inserted updated, deleted), so it's very important to set the
+ * right flush mode (FLUSH_AT_TXN_BOUNDARY being the default).
+ */
+ PgStat_FlushMode flush_mode;
+
/*
* The size of an entry in the shared stats hash table (pointed to by
* PgStatShared_HashEntry->body). For fixed-numbered statistics, this is
diff --git a/src/include/utils/timeout.h b/src/include/utils/timeout.h
index 0965b590b34..10723bb664c 100644
--- a/src/include/utils/timeout.h
+++ b/src/include/utils/timeout.h
@@ -35,6 +35,7 @@ typedef enum TimeoutId
IDLE_SESSION_TIMEOUT,
IDLE_STATS_UPDATE_TIMEOUT,
CLIENT_CONNECTION_CHECK_TIMEOUT,
+ ANYTIME_STATS_UPDATE_TIMEOUT,
STARTUP_PROGRESS_TIMEOUT,
/* First user-definable timeout reason */
USER_TIMEOUT,
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index ddbe4c64971..af21c87234a 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -2268,6 +2268,7 @@ PgStat_Counter
PgStat_EntryRef
PgStat_EntryRefHashEntry
PgStat_FetchConsistency
+PgStat_FlushMode
PgStat_FunctionCallUsage
PgStat_FunctionCounts
PgStat_HashKey
--
2.34.1
--wR/mWGXukst4NraF
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
filename="v4-0002-Add-GUC-to-specify-non-transactional-statistics-f.patch"
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2023-07-22 22:04 [PATCH v8 1/4] Make binaryheap available to frontend code. Nathan Bossart <[email protected]>
2026-01-05 09:41 [PATCH v5 1/4] Add pgstat_report_anytime_stat() for periodic stats flushing Bertrand Drouvot <[email protected]>
2026-01-05 09:41 [PATCH v7 1/5] Add pgstat_report_anytime_stat() for periodic stats flushing Bertrand Drouvot <[email protected]>
2026-01-05 09:41 [PATCH v10 1/5] Add pgstat_report_anytime_stat() for periodic stats flushing Bertrand Drouvot <[email protected]>
2026-01-05 09:41 [PATCH v11 1/5] Add pgstat_report_anytime_stat() for periodic stats flushing Bertrand Drouvot <[email protected]>
2026-01-05 09:41 [PATCH v2 1/3] Add pgstat_report_anytime_stat() for periodic stats flushing Bertrand Drouvot <[email protected]>
2026-01-05 09:41 [PATCH v4 1/4] Add pgstat_report_anytime_stat() for periodic stats flushing Bertrand Drouvot <[email protected]>
2026-01-05 09:41 [PATCH v6 1/5] Add pgstat_report_anytime_stat() for periodic stats flushing Bertrand Drouvot <[email protected]>
2026-01-05 09:41 [PATCH v8 1/5] Add pgstat_report_anytime_stat() for periodic stats flushing Bertrand Drouvot <[email protected]>
2026-01-05 09:41 [PATCH v9 1/5] Add pgstat_report_anytime_stat() for periodic stats flushing Bertrand Drouvot <[email protected]>
2026-01-05 09:41 [PATCH v1 1/3] Add pgstat_report_anytime_stat() for periodic stats flushing Bertrand Drouvot <[email protected]>
2026-01-05 09:41 [PATCH v3 1/3] Add pgstat_report_anytime_stat() for periodic stats flushing Bertrand Drouvot <[email protected]>
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