From: Michael Paquier Date: Tue, 24 Mar 2026 06:32:09 +0000 (+0900) Subject: Add support for lock statistics in pgstats X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=4019f725f5d4;p=thirdparty%2Fpostgresql.git Add support for lock statistics in pgstats This commit adds a new stats kind, called PGSTAT_KIND_LOCK, implementing statistics for lock tags, as reported by pg_locks. The implementation is fixed-sized, as the data is caped based on the number of lock tags in LockTagType. The new statistics kind records the following fields, providing insight regarding lock behavior, while avoiding impact on performance-critical code paths (such as fast-path lock acquisition): - waits and wait_time: respectively track the number of times a lock required waiting and the total time spent acquiring it. These metrics are only collected once a lock is successfully acquired and after deadlock_timeout has been exceeded. fastpath_exceeded: counts how often a lock could not be acquired via the fast path due to the max_locks_per_transaction slot limits. A new view called pg_stat_lock can be used to access this data, coupled with a SQL function called pg_stat_get_lock(). Bump stat file format PGSTAT_FILE_FORMAT_ID. Bump catalog version. Author: Bertrand Drouvot Reviewed-by: Andres Freund Reviewed-by: Michael Paquier Discussion: https://postgr.es/m/aIyNxBWFCybgBZBS%40ip-10-97-1-34.eu-west-3.compute.internal --- diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml index 462019a972c..bb75ed1069b 100644 --- a/doc/src/sgml/monitoring.sgml +++ b/doc/src/sgml/monitoring.sgml @@ -509,6 +509,15 @@ postgres 27093 0.0 0.0 30096 2752 ? Ss 11:34 0:00 postgres: ser + + pg_stat_lockpg_stat_lock + + One row for each lock type, containing cluster-wide locks statistics. + See + pg_stat_lock for details. + + + pg_stat_replication_slotspg_stat_replication_slots One row per replication slot, showing statistics about the @@ -3283,6 +3292,101 @@ description | Waiting for a newly initialized WAL file to reach durable storage + + + <structname>pg_stat_lock</structname> + + + pg_stat_lock + + + + The pg_stat_lock view will contain one row for each + lock type, showing cluster-wide locks statistics. + + + + <structname>pg_stat_lock</structname> View + + + + + + Column Type + + + Description + + + + + + + + + locktype text + + + Type of the lockable object. See + pg_locks for details. + + + + + + + + waits bigint + + + Number of times a lock of this type had to wait because of a + conflicting lock. Only incremented when the lock was successfully + acquired after waiting longer than . + + + + + + + + wait_time bigint + + + Total time spent waiting for locks of this type, in milliseconds. + Only incremented when the lock was successfully acquired after waiting + longer than . + + + + + + + + fastpath_exceeded bigint + + + Number of times a lock of this type could not be acquired via fast path + because the fast path slot limit was exceeded. Increasing + can reduce this number. + + + + + + + + stats_reset timestamp with time zone + + + Time at which these statistics were last reset. + + + + + +
+ + <structname>pg_stat_bgwriter</structname> @@ -5372,6 +5476,12 @@ description | Waiting for a newly initialized WAL file to reach durable storage pg_stat_io view. + + + lock: Reset all the counters shown in the + pg_stat_lock view. + + recovery_prefetch: Reset all the counters shown in diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql index f1ed7b58f13..e54018004db 100644 --- a/src/backend/catalog/system_views.sql +++ b/src/backend/catalog/system_views.sql @@ -985,6 +985,15 @@ CREATE VIEW pg_stat_slru AS s.stats_reset FROM pg_stat_get_slru() s; +CREATE VIEW pg_stat_lock AS + SELECT + l.locktype, + l.waits, + l.wait_time, + l.fastpath_exceeded, + l.stats_reset + FROM pg_stat_get_lock() l; + CREATE VIEW pg_stat_wal_receiver AS SELECT s.pid, diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c index f875e434ee1..234643e4dd7 100644 --- a/src/backend/storage/lmgr/lock.c +++ b/src/backend/storage/lmgr/lock.c @@ -39,6 +39,7 @@ #include "access/xlogutils.h" #include "miscadmin.h" #include "pg_trace.h" +#include "pgstat.h" #include "storage/lmgr.h" #include "storage/proc.h" #include "storage/procarray.h" @@ -1018,6 +1019,14 @@ LockAcquireExtended(const LOCKTAG *locktag, return LOCKACQUIRE_OK; } } + else + { + /* + * Increment the lock statistics counter if lock could not be + * acquired via the fast-path. + */ + pgstat_count_lock_fastpath_exceeded(locallock->tag.lock.locktag_type); + } } /* diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index a2ec2ce6d72..ec41c86f390 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -1549,8 +1549,9 @@ ProcSleep(LOCALLOCK *locallock) } /* - * If awoken after the deadlock check interrupt has run, and - * log_lock_waits is on, then report about the wait. + * If awoken after the deadlock check interrupt has run, increment the + * lock statistics counters and if log_lock_waits is on, then report + * about the wait. */ if (deadlock_state != DS_NOT_YET_CHECKED) { @@ -1564,6 +1565,10 @@ ProcSleep(LOCALLOCK *locallock) msecs = secs * 1000 + usecs / 1000; usecs = usecs % 1000; + /* Increment the lock statistics counters if done waiting. */ + if (myWaitStatus == PROC_WAIT_STATUS_OK) + pgstat_count_lock_waits(locallock->tag.lock.locktag_type, msecs); + if (log_lock_waits) { StringInfoData buf, diff --git a/src/backend/utils/activity/Makefile b/src/backend/utils/activity/Makefile index c37bfb350bb..ca3ef89bf59 100644 --- a/src/backend/utils/activity/Makefile +++ b/src/backend/utils/activity/Makefile @@ -26,6 +26,7 @@ OBJS = \ pgstat_database.o \ pgstat_function.o \ pgstat_io.o \ + pgstat_lock.o \ pgstat_relation.o \ pgstat_replslot.o \ pgstat_shmem.o \ diff --git a/src/backend/utils/activity/meson.build b/src/backend/utils/activity/meson.build index 53bd5a246ca..1aa7ece5290 100644 --- a/src/backend/utils/activity/meson.build +++ b/src/backend/utils/activity/meson.build @@ -11,6 +11,7 @@ backend_sources += files( 'pgstat_database.c', 'pgstat_function.c', 'pgstat_io.c', + 'pgstat_lock.c', 'pgstat_relation.c', 'pgstat_replslot.c', 'pgstat_shmem.c', diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c index 11bb71cad5a..eb8ccbaa628 100644 --- a/src/backend/utils/activity/pgstat.c +++ b/src/backend/utils/activity/pgstat.c @@ -83,6 +83,7 @@ * - pgstat_database.c * - pgstat_function.c * - pgstat_io.c + * - pgstat_lock.c * - pgstat_relation.c * - pgstat_replslot.c * - pgstat_slru.c @@ -448,6 +449,23 @@ static const PgStat_KindInfo pgstat_kind_builtin_infos[PGSTAT_KIND_BUILTIN_SIZE] .snapshot_cb = pgstat_io_snapshot_cb, }, + [PGSTAT_KIND_LOCK] = { + .name = "lock", + + .fixed_amount = true, + .write_to_file = true, + + .snapshot_ctl_off = offsetof(PgStat_Snapshot, lock), + .shared_ctl_off = offsetof(PgStat_ShmemControl, lock), + .shared_data_off = offsetof(PgStatShared_Lock, stats), + .shared_data_len = sizeof(((PgStatShared_Lock *) 0)->stats), + + .flush_static_cb = pgstat_lock_flush_cb, + .init_shmem_cb = pgstat_lock_init_shmem_cb, + .reset_all_cb = pgstat_lock_reset_all_cb, + .snapshot_cb = pgstat_lock_snapshot_cb, + }, + [PGSTAT_KIND_SLRU] = { .name = "slru", diff --git a/src/backend/utils/activity/pgstat_lock.c b/src/backend/utils/activity/pgstat_lock.c new file mode 100644 index 00000000000..041f521ce73 --- /dev/null +++ b/src/backend/utils/activity/pgstat_lock.c @@ -0,0 +1,178 @@ +/* ------------------------------------------------------------------------- + * + * pgstat_lock.c + * Implementation of lock statistics. + * + * This file contains the implementation of lock statistics. It is kept + * separate from pgstat.c to enforce the line between the statistics + * access / storage implementation and the details about individual types + * of statistics. + * + * Copyright (c) 2021-2026, PostgreSQL Global Development Group + * + * IDENTIFICATION + * src/backend/utils/activity/pgstat_lock.c + * ------------------------------------------------------------------------- + */ + +#include "postgres.h" + +#include "utils/pgstat_internal.h" + +static PgStat_PendingLock PendingLockStats; +static bool have_lockstats = false; + +PgStat_Lock * +pgstat_fetch_stat_lock(void) +{ + pgstat_snapshot_fixed(PGSTAT_KIND_LOCK); + + return &pgStatLocal.snapshot.lock; +} + +/* + * Simpler wrapper of pgstat_lock_flush_cb() + */ +void +pgstat_lock_flush(bool nowait) +{ + (void) pgstat_lock_flush_cb(nowait); +} + +/* + * Flush out locally pending lock statistics + * + * If no stats have been recorded, this function returns false. + * + * If nowait is true, this function returns true if the lock could not be + * acquired. Otherwise, return false. + */ +bool +pgstat_lock_flush_cb(bool nowait) +{ + LWLock *lcktype_lock; + PgStat_LockEntry *lck_shstats; + bool lock_not_acquired = false; + + if (!have_lockstats) + return false; + + for (int i = 0; i <= LOCKTAG_LAST_TYPE; i++) + { + lcktype_lock = &pgStatLocal.shmem->lock.locks[i]; + lck_shstats = + &pgStatLocal.shmem->lock.stats.stats[i]; + + if (!nowait) + LWLockAcquire(lcktype_lock, LW_EXCLUSIVE); + else if (!LWLockConditionalAcquire(lcktype_lock, LW_EXCLUSIVE)) + { + lock_not_acquired = true; + continue; + } + +#define LOCKSTAT_ACC(fld) \ + (lck_shstats->fld += PendingLockStats.stats[i].fld) + LOCKSTAT_ACC(waits); + LOCKSTAT_ACC(wait_time); + LOCKSTAT_ACC(fastpath_exceeded); +#undef LOCKSTAT_ACC + + LWLockRelease(lcktype_lock); + } + + memset(&PendingLockStats, 0, sizeof(PendingLockStats)); + + have_lockstats = false; + + return lock_not_acquired; +} + + +void +pgstat_lock_init_shmem_cb(void *stats) +{ + PgStatShared_Lock *stat_shmem = (PgStatShared_Lock *) stats; + + for (int i = 0; i <= LOCKTAG_LAST_TYPE; i++) + LWLockInitialize(&stat_shmem->locks[i], LWTRANCHE_PGSTATS_DATA); +} + +void +pgstat_lock_reset_all_cb(TimestampTz ts) +{ + for (int i = 0; i <= LOCKTAG_LAST_TYPE; i++) + { + LWLock *lcktype_lock = &pgStatLocal.shmem->lock.locks[i]; + PgStat_LockEntry *lck_shstats = &pgStatLocal.shmem->lock.stats.stats[i]; + + LWLockAcquire(lcktype_lock, LW_EXCLUSIVE); + + /* + * Use the lock in the first lock type PgStat_LockEntry to protect the + * reset timestamp as well. + */ + if (i == 0) + pgStatLocal.shmem->lock.stats.stat_reset_timestamp = ts; + + memset(lck_shstats, 0, sizeof(*lck_shstats)); + LWLockRelease(lcktype_lock); + } +} + +void +pgstat_lock_snapshot_cb(void) +{ + for (int i = 0; i <= LOCKTAG_LAST_TYPE; i++) + { + LWLock *lcktype_lock = &pgStatLocal.shmem->lock.locks[i]; + PgStat_LockEntry *lck_shstats = &pgStatLocal.shmem->lock.stats.stats[i]; + PgStat_LockEntry *lck_snap = &pgStatLocal.snapshot.lock.stats[i]; + + LWLockAcquire(lcktype_lock, LW_SHARED); + + /* + * Use the lock in the first lock type PgStat_LockEntry to protect the + * reset timestamp as well. + */ + if (i == 0) + pgStatLocal.snapshot.lock.stat_reset_timestamp = + pgStatLocal.shmem->lock.stats.stat_reset_timestamp; + + /* using struct assignment due to better type safety */ + *lck_snap = *lck_shstats; + LWLockRelease(lcktype_lock); + } +} + +/* + * Increment counter for lock not acquired with the fast-path, per lock + * type, due to the fast-path slot limit reached. + * + * Note: This function should not be called in performance-sensitive paths, + * like lock acquisitions. + */ +void +pgstat_count_lock_fastpath_exceeded(uint8 locktag_type) +{ + Assert(locktag_type <= LOCKTAG_LAST_TYPE); + PendingLockStats.stats[locktag_type].fastpath_exceeded++; + have_lockstats = true; + pgstat_report_fixed = true; +} + +/* + * Increment the number of waits and wait time, per lock type. + * + * Note: This function should not be called in performance-sensitive paths, + * like lock acquisitions. + */ +void +pgstat_count_lock_waits(uint8 locktag_type, long msecs) +{ + Assert(locktag_type <= LOCKTAG_LAST_TYPE); + PendingLockStats.stats[locktag_type].waits++; + PendingLockStats.stats[locktag_type].wait_time += (PgStat_Counter) msecs; + have_lockstats = true; + pgstat_report_fixed = true; +} diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c index 5f907335990..9185a8e6b83 100644 --- a/src/backend/utils/adt/pgstatfuncs.c +++ b/src/backend/utils/adt/pgstatfuncs.c @@ -1741,6 +1741,42 @@ pg_stat_get_wal(PG_FUNCTION_ARGS) wal_stats->stat_reset_timestamp)); } +Datum +pg_stat_get_lock(PG_FUNCTION_ARGS) +{ +#define PG_STAT_LOCK_COLS 5 + ReturnSetInfo *rsinfo; + PgStat_Lock *lock_stats; + + InitMaterializedSRF(fcinfo, 0); + rsinfo = (ReturnSetInfo *) fcinfo->resultinfo; + + lock_stats = pgstat_fetch_stat_lock(); + + for (int lcktype = 0; lcktype <= LOCKTAG_LAST_TYPE; lcktype++) + { + const char *locktypename; + Datum values[PG_STAT_LOCK_COLS] = {0}; + bool nulls[PG_STAT_LOCK_COLS] = {0}; + PgStat_LockEntry *lck_stats = &lock_stats->stats[lcktype]; + int i = 0; + + locktypename = LockTagTypeNames[lcktype]; + + values[i++] = CStringGetTextDatum(locktypename); + values[i++] = Int64GetDatum(lck_stats->waits); + values[i++] = Int64GetDatum(lck_stats->wait_time); + values[i++] = Int64GetDatum(lck_stats->fastpath_exceeded); + values[i] = TimestampTzGetDatum(lock_stats->stat_reset_timestamp); + + Assert(i + 1 == PG_STAT_LOCK_COLS); + + tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc, values, nulls); + } + + return (Datum) 0; +} + /* * Returns statistics of SLRU caches. */ @@ -1925,6 +1961,7 @@ pg_stat_reset_shared(PG_FUNCTION_ARGS) pgstat_reset_of_kind(PGSTAT_KIND_BGWRITER); pgstat_reset_of_kind(PGSTAT_KIND_CHECKPOINTER); pgstat_reset_of_kind(PGSTAT_KIND_IO); + pgstat_reset_of_kind(PGSTAT_KIND_LOCK); XLogPrefetchResetStats(); pgstat_reset_of_kind(PGSTAT_KIND_SLRU); pgstat_reset_of_kind(PGSTAT_KIND_WAL); @@ -1942,6 +1979,8 @@ pg_stat_reset_shared(PG_FUNCTION_ARGS) pgstat_reset_of_kind(PGSTAT_KIND_CHECKPOINTER); else if (strcmp(target, "io") == 0) pgstat_reset_of_kind(PGSTAT_KIND_IO); + else if (strcmp(target, "lock") == 0) + pgstat_reset_of_kind(PGSTAT_KIND_LOCK); else if (strcmp(target, "recovery_prefetch") == 0) XLogPrefetchResetStats(); else if (strcmp(target, "slru") == 0) diff --git a/src/include/catalog/catversion.h b/src/include/catalog/catversion.h index 420850293f8..4d9ccc5789c 100644 --- a/src/include/catalog/catversion.h +++ b/src/include/catalog/catversion.h @@ -57,6 +57,6 @@ */ /* yyyymmddN */ -#define CATALOG_VERSION_NO 202603201 +#define CATALOG_VERSION_NO 202603241 #endif diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat index 84e7adde0e5..0118e970dda 100644 --- a/src/include/catalog/pg_proc.dat +++ b/src/include/catalog/pg_proc.dat @@ -6048,6 +6048,14 @@ proargnames => '{backend_type,object,context,reads,read_bytes,read_time,writes,write_bytes,write_time,writebacks,writeback_time,extends,extend_bytes,extend_time,hits,evictions,reuses,fsyncs,fsync_time,stats_reset}', prosrc => 'pg_stat_get_io' }, +{ oid => '9375', descr => 'statistics: per lock type statistics', + proname => 'pg_stat_get_lock', prorows => '10', proretset => 't', + provolatile => 'v', proparallel => 'r', prorettype => 'record', + proargtypes => '', proallargtypes => '{text,int8,int8,int8,timestamptz}', + proargmodes => '{o,o,o,o,o}', + proargnames => '{locktype,waits,wait_time,fastpath_exceeded,stats_reset}', + prosrc => 'pg_stat_get_lock' }, + { oid => '6386', descr => 'statistics: backend IO statistics', proname => 'pg_stat_get_backend_io', prorows => '5', proretset => 't', provolatile => 'v', proparallel => 'r', prorettype => 'record', diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 216b93492ba..8e3549c3752 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -15,6 +15,7 @@ #include "portability/instr_time.h" #include "postmaster/pgarch.h" /* for MAX_XFN_CHARS */ #include "replication/conflict.h" +#include "storage/locktag.h" #include "utils/backend_progress.h" /* for backward compatibility */ /* IWYU pragma: export */ #include "utils/backend_status.h" /* for backward compatibility */ /* IWYU pragma: export */ #include "utils/pgstat_kind.h" @@ -217,7 +218,7 @@ typedef struct PgStat_TableXactStatus * ------------------------------------------------------------ */ -#define PGSTAT_FILE_FORMAT_ID 0x01A5BCBB +#define PGSTAT_FILE_FORMAT_ID 0x01A5BCBC typedef struct PgStat_ArchiverStats { @@ -345,6 +346,24 @@ typedef struct PgStat_IO PgStat_BktypeIO stats[BACKEND_NUM_TYPES]; } PgStat_IO; +typedef struct PgStat_LockEntry +{ + PgStat_Counter waits; + PgStat_Counter wait_time; /* time in milliseconds */ + PgStat_Counter fastpath_exceeded; +} PgStat_LockEntry; + +typedef struct PgStat_PendingLock +{ + PgStat_LockEntry stats[LOCKTAG_LAST_TYPE + 1]; +} PgStat_PendingLock; + +typedef struct PgStat_Lock +{ + TimestampTz stat_reset_timestamp; + PgStat_LockEntry stats[LOCKTAG_LAST_TYPE + 1]; +} PgStat_Lock; + typedef struct PgStat_StatDBEntry { PgStat_Counter xact_commit; @@ -617,6 +636,15 @@ extern bool pgstat_tracks_io_op(BackendType bktype, IOObject io_object, IOContext io_context, IOOp io_op); +/* + * Functions in pgstat_lock.c + */ + +extern void pgstat_lock_flush(bool nowait); +extern void pgstat_count_lock_fastpath_exceeded(uint8 locktag_type); +extern void pgstat_count_lock_waits(uint8 locktag_type, long msecs); +extern PgStat_Lock *pgstat_fetch_stat_lock(void); + /* * Functions in pgstat_database.c */ diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h index 9b8fbae00ed..97704421a92 100644 --- a/src/include/utils/pgstat_internal.h +++ b/src/include/utils/pgstat_internal.h @@ -464,6 +464,16 @@ typedef struct PgStatShared_IO PgStat_IO stats; } PgStatShared_IO; +typedef struct PgStatShared_Lock +{ + /* + * locks[i] protects stats.stats[i]. locks[0] also protects + * stats.stat_reset_timestamp. + */ + LWLock locks[LOCKTAG_LAST_TYPE + 1]; + PgStat_Lock stats; +} PgStatShared_Lock; + typedef struct PgStatShared_SLRU { /* lock protects ->stats */ @@ -570,6 +580,7 @@ typedef struct PgStat_ShmemControl PgStatShared_BgWriter bgwriter; PgStatShared_Checkpointer checkpointer; PgStatShared_IO io; + PgStatShared_Lock lock; PgStatShared_SLRU slru; PgStatShared_Wal wal; @@ -602,6 +613,8 @@ typedef struct PgStat_Snapshot PgStat_IO io; + PgStat_Lock lock; + PgStat_SLRUStats slru[SLRU_NUM_ELEMENTS]; PgStat_WalStats wal; @@ -752,6 +765,14 @@ 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); +/* + * Functions in pgstat_lock.c + */ + +extern bool pgstat_lock_flush_cb(bool nowait); +extern void pgstat_lock_init_shmem_cb(void *stats); +extern void pgstat_lock_reset_all_cb(TimestampTz ts); +extern void pgstat_lock_snapshot_cb(void); /* * Functions in pgstat_relation.c diff --git a/src/include/utils/pgstat_kind.h b/src/include/utils/pgstat_kind.h index c30b6235623..2d78a029683 100644 --- a/src/include/utils/pgstat_kind.h +++ b/src/include/utils/pgstat_kind.h @@ -36,8 +36,9 @@ #define PGSTAT_KIND_BGWRITER 8 #define PGSTAT_KIND_CHECKPOINTER 9 #define PGSTAT_KIND_IO 10 -#define PGSTAT_KIND_SLRU 11 -#define PGSTAT_KIND_WAL 12 +#define PGSTAT_KIND_LOCK 11 +#define PGSTAT_KIND_SLRU 12 +#define PGSTAT_KIND_WAL 13 #define PGSTAT_KIND_BUILTIN_MIN PGSTAT_KIND_DATABASE #define PGSTAT_KIND_BUILTIN_MAX PGSTAT_KIND_WAL diff --git a/src/test/isolation/expected/lock-stats.out b/src/test/isolation/expected/lock-stats.out new file mode 100644 index 00000000000..160f0c9ba5f --- /dev/null +++ b/src/test/isolation/expected/lock-stats.out @@ -0,0 +1,197 @@ +Parsed test spec with 2 sessions + +starting permutation: s1_set_deadlock_timeout s1_reset_stat_lock s2_set_deadlock_timeout s1_begin s1_lock_relation s2_begin s2_ff s2_lock_relation s1_sleep s1_commit s2_commit s2_report_stat_lock_relation +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s1_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s1_reset_stat_lock: SELECT pg_stat_reset_shared('lock'); +pg_stat_reset_shared +-------------------- + +(1 row) + +step s2_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s1_begin: BEGIN; +step s1_lock_relation: LOCK TABLE test_stat_tab; +step s2_begin: BEGIN; +step s2_ff: SELECT pg_stat_force_next_flush(); +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s2_lock_relation: LOCK TABLE test_stat_tab; +step s1_sleep: SELECT pg_sleep(0.05); +pg_sleep +-------- + +(1 row) + +step s1_commit: COMMIT; +step s2_lock_relation: <... completed> +step s2_commit: COMMIT; +step s2_report_stat_lock_relation: + SELECT waits > 0 AS has_waits, wait_time > 50 AS has_wait_time + FROM pg_stat_lock WHERE locktype = 'relation'; + +has_waits|has_wait_time +---------+------------- +t |t +(1 row) + + +starting permutation: s1_set_deadlock_timeout s1_reset_stat_lock s2_set_deadlock_timeout s2_set_log_lock_waits s1_table_insert s1_begin s1_table_update_k1 s2_begin s2_ff s2_table_update_k1 s1_sleep s1_commit s2_commit s2_report_stat_lock_transactionid +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s1_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s1_reset_stat_lock: SELECT pg_stat_reset_shared('lock'); +pg_stat_reset_shared +-------------------- + +(1 row) + +step s2_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s2_set_log_lock_waits: SET log_lock_waits = on; +step s1_table_insert: INSERT INTO test_stat_tab(key, value) VALUES('k1', 1), ('k2', 1), ('k3', 1); +step s1_begin: BEGIN; +step s1_table_update_k1: UPDATE test_stat_tab SET value = value + 1 WHERE key = 'k1'; +step s2_begin: BEGIN; +step s2_ff: SELECT pg_stat_force_next_flush(); +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s2_table_update_k1: UPDATE test_stat_tab SET value = value + 1 WHERE key = 'k1'; +step s1_sleep: SELECT pg_sleep(0.05); +pg_sleep +-------- + +(1 row) + +step s1_commit: COMMIT; +step s2_table_update_k1: <... completed> +step s2_commit: COMMIT; +step s2_report_stat_lock_transactionid: + SELECT waits > 0 AS has_waits, wait_time > 50 AS has_wait_time + FROM pg_stat_lock WHERE locktype = 'transactionid'; + +has_waits|has_wait_time +---------+------------- +t |t +(1 row) + + +starting permutation: s1_set_deadlock_timeout s1_reset_stat_lock s2_set_deadlock_timeout s2_set_log_lock_waits s1_lock_advisory_lock s2_begin s2_ff s2_lock_advisory_lock s1_sleep s1_lock_advisory_unlock s2_lock_advisory_unlock s2_commit s2_report_stat_lock_advisory +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s1_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s1_reset_stat_lock: SELECT pg_stat_reset_shared('lock'); +pg_stat_reset_shared +-------------------- + +(1 row) + +step s2_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s2_set_log_lock_waits: SET log_lock_waits = on; +step s1_lock_advisory_lock: SELECT pg_advisory_lock(1); +pg_advisory_lock +---------------- + +(1 row) + +step s2_begin: BEGIN; +step s2_ff: SELECT pg_stat_force_next_flush(); +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s2_lock_advisory_lock: SELECT pg_advisory_lock(1); +step s1_sleep: SELECT pg_sleep(0.05); +pg_sleep +-------- + +(1 row) + +step s1_lock_advisory_unlock: SELECT pg_advisory_unlock(1); +pg_advisory_unlock +------------------ +t +(1 row) + +step s2_lock_advisory_lock: <... completed> +pg_advisory_lock +---------------- + +(1 row) + +step s2_lock_advisory_unlock: SELECT pg_advisory_unlock(1); +pg_advisory_unlock +------------------ +t +(1 row) + +step s2_commit: COMMIT; +step s2_report_stat_lock_advisory: + SELECT waits > 0 AS has_waits, wait_time > 50 AS has_wait_time + FROM pg_stat_lock WHERE locktype = 'advisory'; + +has_waits|has_wait_time +---------+------------- +t |t +(1 row) + + +starting permutation: s1_set_deadlock_timeout s1_reset_stat_lock s2_set_deadlock_timeout s2_unset_log_lock_waits s1_begin s1_lock_relation s2_begin s2_ff s2_lock_relation s1_sleep s1_commit s2_commit s2_report_stat_lock_relation +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s1_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s1_reset_stat_lock: SELECT pg_stat_reset_shared('lock'); +pg_stat_reset_shared +-------------------- + +(1 row) + +step s2_set_deadlock_timeout: SET deadlock_timeout = '10ms'; +step s2_unset_log_lock_waits: SET log_lock_waits = off; +step s1_begin: BEGIN; +step s1_lock_relation: LOCK TABLE test_stat_tab; +step s2_begin: BEGIN; +step s2_ff: SELECT pg_stat_force_next_flush(); +pg_stat_force_next_flush +------------------------ + +(1 row) + +step s2_lock_relation: LOCK TABLE test_stat_tab; +step s1_sleep: SELECT pg_sleep(0.05); +pg_sleep +-------- + +(1 row) + +step s1_commit: COMMIT; +step s2_lock_relation: <... completed> +step s2_commit: COMMIT; +step s2_report_stat_lock_relation: + SELECT waits > 0 AS has_waits, wait_time > 50 AS has_wait_time + FROM pg_stat_lock WHERE locktype = 'relation'; + +has_waits|has_wait_time +---------+------------- +t |t +(1 row) + diff --git a/src/test/isolation/isolation_schedule b/src/test/isolation/isolation_schedule index 4e466580cd4..2cc86849c9a 100644 --- a/src/test/isolation/isolation_schedule +++ b/src/test/isolation/isolation_schedule @@ -43,6 +43,7 @@ test: eval-plan-qual-trigger test: inplace-inval test: intra-grant-inplace test: intra-grant-inplace-db +test: lock-stats test: lock-update-delete test: lock-update-traversal test: inherit-temp diff --git a/src/test/isolation/specs/lock-stats.spec b/src/test/isolation/specs/lock-stats.spec new file mode 100644 index 00000000000..e688642864c --- /dev/null +++ b/src/test/isolation/specs/lock-stats.spec @@ -0,0 +1,128 @@ +# Test for the lock statistics +# +# This test creates multiple locking situations when a session (s2) has to +# wait on a lock for longer than deadlock_timeout. The first permutations +# test various lock tags. The last permutation checks that log_lock_waits +# has no impact on the statistics counters. + +setup +{ + CREATE TABLE test_stat_tab(key text not null, value int); + INSERT INTO test_stat_tab(key, value) VALUES('k0', 1); + SELECT pg_stat_force_next_flush(); +} + +teardown +{ + DROP TABLE IF EXISTS test_stat_tab; +} + +session s1 +setup { SET stats_fetch_consistency = 'none'; } +step s1_begin { BEGIN; } +step s1_commit { COMMIT; } +step s1_table_insert { INSERT INTO test_stat_tab(key, value) VALUES('k1', 1), ('k2', 1), ('k3', 1);} +step s1_table_update_k1 { UPDATE test_stat_tab SET value = value + 1 WHERE key = 'k1';} +step s1_set_deadlock_timeout { SET deadlock_timeout = '10ms'; } +step s1_reset_stat_lock { SELECT pg_stat_reset_shared('lock'); } +step s1_sleep { SELECT pg_sleep(0.05); } +step s1_lock_relation { LOCK TABLE test_stat_tab; } +step s1_lock_advisory_lock { SELECT pg_advisory_lock(1); } +step s1_lock_advisory_unlock { SELECT pg_advisory_unlock(1); } + +session s2 +setup { SET stats_fetch_consistency = 'none'; } +step s2_begin { BEGIN; } +step s2_commit { COMMIT; } +step s2_ff { SELECT pg_stat_force_next_flush(); } +step s2_table_update_k1 { UPDATE test_stat_tab SET value = value + 1 WHERE key = 'k1';} +step s2_set_deadlock_timeout { SET deadlock_timeout = '10ms'; } +step s2_set_log_lock_waits { SET log_lock_waits = on; } +step s2_unset_log_lock_waits { SET log_lock_waits = off; } +step s2_report_stat_lock_relation { + SELECT waits > 0 AS has_waits, wait_time > 50 AS has_wait_time + FROM pg_stat_lock WHERE locktype = 'relation'; +} +step s2_report_stat_lock_transactionid { + SELECT waits > 0 AS has_waits, wait_time > 50 AS has_wait_time + FROM pg_stat_lock WHERE locktype = 'transactionid'; +} +step s2_report_stat_lock_advisory { + SELECT waits > 0 AS has_waits, wait_time > 50 AS has_wait_time + FROM pg_stat_lock WHERE locktype = 'advisory'; +} +step s2_lock_relation { LOCK TABLE test_stat_tab; } +step s2_lock_advisory_lock { SELECT pg_advisory_lock(1); } +step s2_lock_advisory_unlock { SELECT pg_advisory_unlock(1); } + +###################### +# Lock stats tests +###################### + +# relation lock + +permutation + s1_set_deadlock_timeout + s1_reset_stat_lock + s2_set_deadlock_timeout + s1_begin + s1_lock_relation + s2_begin + s2_ff + s2_lock_relation + s1_sleep + s1_commit + s2_commit + s2_report_stat_lock_relation + +# transaction lock + +permutation + s1_set_deadlock_timeout + s1_reset_stat_lock + s2_set_deadlock_timeout + s2_set_log_lock_waits + s1_table_insert + s1_begin + s1_table_update_k1 + s2_begin + s2_ff + s2_table_update_k1 + s1_sleep + s1_commit + s2_commit + s2_report_stat_lock_transactionid + +# advisory lock + +permutation + s1_set_deadlock_timeout + s1_reset_stat_lock + s2_set_deadlock_timeout + s2_set_log_lock_waits + s1_lock_advisory_lock + s2_begin + s2_ff + s2_lock_advisory_lock + s1_sleep + s1_lock_advisory_unlock + s2_lock_advisory_unlock + s2_commit + s2_report_stat_lock_advisory + +# Ensure log_lock_waits has no impact + +permutation + s1_set_deadlock_timeout + s1_reset_stat_lock + s2_set_deadlock_timeout + s2_unset_log_lock_waits + s1_begin + s1_lock_relation + s2_begin + s2_ff + s2_lock_relation + s1_sleep + s1_commit + s2_commit + s2_report_stat_lock_relation diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out index 32bea58db2c..2b3cf6d8569 100644 --- a/src/test/regress/expected/rules.out +++ b/src/test/regress/expected/rules.out @@ -1952,6 +1952,12 @@ pg_stat_io| SELECT backend_type, fsync_time, stats_reset FROM pg_stat_get_io() b(backend_type, object, context, reads, read_bytes, read_time, writes, write_bytes, write_time, writebacks, writeback_time, extends, extend_bytes, extend_time, hits, evictions, reuses, fsyncs, fsync_time, stats_reset); +pg_stat_lock| SELECT locktype, + waits, + wait_time, + fastpath_exceeded, + stats_reset + FROM pg_stat_get_lock() l(locktype, waits, wait_time, fastpath_exceeded, stats_reset); pg_stat_progress_analyze| SELECT s.pid, s.datid, d.datname, diff --git a/src/test/regress/expected/stats.out b/src/test/regress/expected/stats.out index b99462bf946..ea7f7846895 100644 --- a/src/test/regress/expected/stats.out +++ b/src/test/regress/expected/stats.out @@ -1958,4 +1958,52 @@ SELECT * FROM check_estimated_rows('SELECT * FROM table_fillfactor'); (1 row) DROP TABLE table_fillfactor; +-- Test fastpath_exceeded stat +CREATE TABLE part_test (id int) PARTITION BY RANGE (id); +SELECT pg_stat_reset_shared('lock'); + pg_stat_reset_shared +---------------------- + +(1 row) + +-- Create partitions (exceeds number of slots) +DO $$ +DECLARE + max_locks int; +BEGIN + SELECT setting::int INTO max_locks + FROM pg_settings + WHERE name = 'max_locks_per_transaction'; + + FOR i IN 1..(max_locks + 10) LOOP + EXECUTE format( + 'CREATE TABLE part_test_%s PARTITION OF part_test + FOR VALUES FROM (%s) TO (%s)', + i, (i-1)*1000, i*1000 + ); + END LOOP; +END; +$$; +SELECT fastpath_exceeded AS fastpath_exceeded_before FROM pg_stat_lock WHERE locktype = 'relation' \gset +-- Needs a lock on each partition +SELECT count(*) FROM part_test; + count +------- + 0 +(1 row) + +-- Ensure pending stats are flushed +SELECT pg_stat_force_next_flush(); + pg_stat_force_next_flush +-------------------------- + +(1 row) + +SELECT fastpath_exceeded > :fastpath_exceeded_before FROM pg_stat_lock WHERE locktype = 'relation'; + ?column? +---------- + t +(1 row) + +DROP TABLE part_test; -- End of Stats Test diff --git a/src/test/regress/sql/stats.sql b/src/test/regress/sql/stats.sql index 941222cf0be..65d8968c83e 100644 --- a/src/test/regress/sql/stats.sql +++ b/src/test/regress/sql/stats.sql @@ -964,4 +964,40 @@ SELECT * FROM check_estimated_rows('SELECT * FROM table_fillfactor'); DROP TABLE table_fillfactor; +-- Test fastpath_exceeded stat +CREATE TABLE part_test (id int) PARTITION BY RANGE (id); + +SELECT pg_stat_reset_shared('lock'); + +-- Create partitions (exceeds number of slots) +DO $$ +DECLARE + max_locks int; +BEGIN + SELECT setting::int INTO max_locks + FROM pg_settings + WHERE name = 'max_locks_per_transaction'; + + FOR i IN 1..(max_locks + 10) LOOP + EXECUTE format( + 'CREATE TABLE part_test_%s PARTITION OF part_test + FOR VALUES FROM (%s) TO (%s)', + i, (i-1)*1000, i*1000 + ); + END LOOP; +END; +$$; + +SELECT fastpath_exceeded AS fastpath_exceeded_before FROM pg_stat_lock WHERE locktype = 'relation' \gset + +-- Needs a lock on each partition +SELECT count(*) FROM part_test; + +-- Ensure pending stats are flushed +SELECT pg_stat_force_next_flush(); + +SELECT fastpath_exceeded > :fastpath_exceeded_before FROM pg_stat_lock WHERE locktype = 'relation'; + +DROP TABLE part_test; + -- End of Stats Test diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list index 0c07c945f05..8df23840e57 100644 --- a/src/tools/pgindent/typedefs.list +++ b/src/tools/pgindent/typedefs.list @@ -2282,6 +2282,7 @@ PgStatShared_Database PgStatShared_Function PgStatShared_HashEntry PgStatShared_IO +PgStatShared_Lock PgStatShared_Relation PgStatShared_ReplSlot PgStatShared_SLRU @@ -2304,8 +2305,11 @@ PgStat_HashKey PgStat_IO PgStat_KindInfo PgStat_LocalState +PgStat_Lock +PgStat_LockEntry PgStat_PendingDroppedStatsItem PgStat_PendingIO +PgStat_PendingLock PgStat_SLRUStats PgStat_ShmemControl PgStat_Snapshot