diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml index 673a0e73e4..6d56912221 100644 --- a/doc/src/sgml/monitoring.sgml +++ b/doc/src/sgml/monitoring.sgml @@ -424,6 +424,13 @@ postgres 27093 0.0 0.0 30096 2752 ? Ss 11:34 0:00 postgres: ser + + pg_stat_walpg_stat_wal + One row only, showing statistics about the WAL writing activity. See + for details. + + + pg_stat_databasepg_stat_database One row per database, showing database-wide statistics. See @@ -3280,6 +3287,56 @@ SELECT pid, wait_event_type, wait_event FROM pg_stat_activity WHERE wait_event i + + <structname>pg_stat_wal</structname> + + + pg_stat_wal + + + + The pg_stat_wal view will always have a + single row, containing data about the WAL writing activity of the cluster. + + + + <structname>pg_stat_wal</structname> View + + + + + Column Type + + + Description + + + + + + + + wal_buffers_full bigint + + + Number of WAL writes when the are full + + + + + + stats_reset timestamp with time zone + + + Time at which these statistics were last reset + + + + +
+ + + <structname>pg_stat_database</structname> @@ -4668,8 +4725,9 @@ SELECT pid, wait_event_type, wait_event FROM pg_stat_activity WHERE wait_event i argument. The argument can be bgwriter to reset all the counters shown in the pg_stat_bgwriter - view, or archiver to reset all the counters shown in - the pg_stat_archiver view. + view, archiver to reset all the counters shown in + the pg_stat_archiver view ,or wal + to reset all the counters shown in the pg_stat_wal view. This function is restricted to superusers by default, but other users diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 61754312e2..3a06cacefb 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -2195,6 +2195,7 @@ AdvanceXLInsertBuffer(XLogRecPtr upto, bool opportunistic) WriteRqst.Flush = 0; XLogWrite(WriteRqst, false); LWLockRelease(WALWriteLock); + WalStats.m_wal_buffers_full++; TRACE_POSTGRESQL_WAL_BUFFER_WRITE_DIRTY_DONE(); } /* Re-acquire WALBufMappingLock and retry */ diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql index ed4f3f142d..643445c189 100644 --- a/src/backend/catalog/system_views.sql +++ b/src/backend/catalog/system_views.sql @@ -979,6 +979,11 @@ CREATE VIEW pg_stat_bgwriter AS pg_stat_get_buf_alloc() AS buffers_alloc, pg_stat_get_bgwriter_stat_reset_time() AS stats_reset; +CREATE VIEW pg_stat_wal AS + SELECT + pg_stat_get_wal_buffers_full() AS wal_buffers_full, + pg_stat_get_wal_stat_reset_time() AS stats_reset; + CREATE VIEW pg_stat_progress_analyze AS SELECT S.pid AS pid, S.datid AS datid, D.datname AS datname, diff --git a/src/backend/postmaster/autovacuum.c b/src/backend/postmaster/autovacuum.c index 2cef56f115..8dca6628de 100644 --- a/src/backend/postmaster/autovacuum.c +++ b/src/backend/postmaster/autovacuum.c @@ -795,6 +795,13 @@ AutoVacLauncherMain(int argc, char *argv[]) current_time, 0)) launch_worker(current_time); } + + /* + * Send wal statistics because some xlog may be written. + * It accesses the system table, which may cause HOT + * pruning or killing of dead index tuple. + */ + pgstat_send_wal(); } AutoVacLauncherShutdown(); diff --git a/src/backend/postmaster/checkpointer.c b/src/backend/postmaster/checkpointer.c index 3e7dcd4f76..1f4fee1f3b 100644 --- a/src/backend/postmaster/checkpointer.c +++ b/src/backend/postmaster/checkpointer.c @@ -504,6 +504,9 @@ CheckpointerMain(void) */ pgstat_send_bgwriter(); + /* Send wal statistics to the stats collector. */ + pgstat_send_wal(); + /* * If any checkpoint flags have been set, redo the loop to handle the * checkpoint without sleeping. diff --git a/src/backend/postmaster/pgstat.c b/src/backend/postmaster/pgstat.c index e6be2b7836..7127beca66 100644 --- a/src/backend/postmaster/pgstat.c +++ b/src/backend/postmaster/pgstat.c @@ -141,6 +141,13 @@ char *pgstat_stat_tmpname = NULL; */ PgStat_MsgBgWriter BgWriterStats; +/* + * WAL global statistics counter. + * This counter is incremented by both each backend and background. + * And then, sent to the stat collector process. + */ +PgStat_MsgWal WalStats; + /* * List of SLRU names that we keep stats for. There is no central registry of * SLRUs, so we use this fixed list instead. The "other" entry is used for @@ -281,6 +288,7 @@ static int localNumBackends = 0; */ static PgStat_ArchiverStats archiverStats; static PgStat_GlobalStats globalStats; +static PgStat_WalStats walStats; static PgStat_SLRUStats slruStats[SLRU_NUM_ELEMENTS]; /* @@ -353,6 +361,7 @@ static void pgstat_recv_vacuum(PgStat_MsgVacuum *msg, int len); static void pgstat_recv_analyze(PgStat_MsgAnalyze *msg, int len); static void pgstat_recv_archiver(PgStat_MsgArchiver *msg, int len); static void pgstat_recv_bgwriter(PgStat_MsgBgWriter *msg, int len); +static void pgstat_recv_wal(PgStat_MsgWal *msg, int len); static void pgstat_recv_slru(PgStat_MsgSLRU *msg, int len); static void pgstat_recv_funcstat(PgStat_MsgFuncstat *msg, int len); static void pgstat_recv_funcpurge(PgStat_MsgFuncpurge *msg, int len); @@ -938,6 +947,9 @@ pgstat_report_stat(bool force) /* Now, send function statistics */ pgstat_send_funcstats(); + /* Send wal statistics */ + pgstat_send_wal(); + /* Finally send SLRU statistics */ pgstat_send_slru(); } @@ -1370,11 +1382,13 @@ pgstat_reset_shared_counters(const char *target) msg.m_resettarget = RESET_ARCHIVER; else if (strcmp(target, "bgwriter") == 0) msg.m_resettarget = RESET_BGWRITER; + else if (strcmp(target, "wal") == 0) + msg.m_resettarget = RESET_WAL; else ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("unrecognized reset target: \"%s\"", target), - errhint("Target must be \"archiver\" or \"bgwriter\"."))); + errhint("Target must be \"archiver\", \"bgwriter\" or \"wal\"."))); pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_RESETSHAREDCOUNTER); pgstat_send(&msg, sizeof(msg)); @@ -2674,6 +2688,21 @@ pgstat_fetch_global(void) return &globalStats; } +/* + * --------- + * pgstat_fetch_stat_wal() - + * + * Support function for the SQL-callable pgstat* functions. Returns + * a pointer to the wal statistics struct. + * --------- + */ +PgStat_WalStats * +pgstat_fetch_stat_wal(void) +{ + backend_read_statsfile(); + + return &walStats; +} /* * --------- @@ -4419,6 +4448,38 @@ pgstat_send_bgwriter(void) MemSet(&BgWriterStats, 0, sizeof(BgWriterStats)); } +/* ---------- + * pgstat_send_wal() - + * + * Send wal statistics to the collector + * ---------- + */ +void +pgstat_send_wal(void) +{ + /* We assume this initializes to zeroes */ + static const PgStat_MsgWal all_zeroes; + + /* + * This function can be called even if nothing at all has happened. In + * this case, avoid sending a completely empty message to the stats + * collector. + */ + if (memcmp(&WalStats, &all_zeroes, sizeof(PgStat_MsgWal)) == 0) + return; + + /* + * Prepare and send the message + */ + pgstat_setheader(&WalStats.m_hdr, PGSTAT_MTYPE_WAL); + pgstat_send(&WalStats, sizeof(WalStats)); + + /* + * Clear out the statistics buffer, so it can be re-used. + */ + MemSet(&WalStats, 0, sizeof(WalStats)); +} + /* ---------- * pgstat_send_slru() - * @@ -4658,6 +4719,10 @@ PgstatCollectorMain(int argc, char *argv[]) pgstat_recv_bgwriter(&msg.msg_bgwriter, len); break; + case PGSTAT_MTYPE_WAL: + pgstat_recv_wal(&msg.msg_wal, len); + break; + case PGSTAT_MTYPE_SLRU: pgstat_recv_slru(&msg.msg_slru, len); break; @@ -4927,6 +4992,12 @@ pgstat_write_statsfiles(bool permanent, bool allDbs) rc = fwrite(&archiverStats, sizeof(archiverStats), 1, fpout); (void) rc; /* we'll check for error with ferror */ + /* + * Write wal stats struct + */ + rc = fwrite(&walStats, sizeof(walStats), 1, fpout); + (void) rc; /* we'll check for error with ferror */ + /* * Write SLRU stats struct */ @@ -5186,11 +5257,12 @@ pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep) HASH_ELEM | HASH_BLOBS | HASH_CONTEXT); /* - * Clear out global and archiver statistics so they start from zero in + * Clear out global, archiver and wal statistics so they start from zero in * case we can't load an existing statsfile. */ memset(&globalStats, 0, sizeof(globalStats)); memset(&archiverStats, 0, sizeof(archiverStats)); + memset(&walStats, 0, sizeof(walStats)); memset(&slruStats, 0, sizeof(slruStats)); /* @@ -5199,6 +5271,7 @@ pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep) */ globalStats.stat_reset_timestamp = GetCurrentTimestamp(); archiverStats.stat_reset_timestamp = globalStats.stat_reset_timestamp; + walStats.stat_reset_timestamp = globalStats.stat_reset_timestamp; /* * Set the same reset timestamp for all SLRU items too. @@ -5268,6 +5341,17 @@ pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep) goto done; } + /* + * Read wal stats struct + */ + if (fread(&walStats, 1, sizeof(walStats), fpin) != sizeof(walStats)) + { + ereport(pgStatRunningInCollector ? LOG : WARNING, + (errmsg("corrupted statistics file \"%s\"", statfile))); + memset(&walStats, 0, sizeof(walStats)); + goto done; + } + /* * Read SLRU stats struct */ @@ -5633,6 +5717,17 @@ pgstat_read_db_statsfile_timestamp(Oid databaseid, bool permanent, return false; } + /* + * Read wal stats struct + */ + if (fread(&walStats, 1, sizeof(walStats), fpin) != sizeof(walStats)) + { + ereport(pgStatRunningInCollector ? LOG : WARNING, + (errmsg("corrupted statistics file \"%s\"", statfile))); + FreeFile(fpin); + return false; + } + /* * Read SLRU stats struct */ @@ -6213,6 +6308,12 @@ pgstat_recv_resetsharedcounter(PgStat_MsgResetsharedcounter *msg, int len) memset(&archiverStats, 0, sizeof(archiverStats)); archiverStats.stat_reset_timestamp = GetCurrentTimestamp(); } + else if (msg->m_resettarget == RESET_WAL) + { + /* Reset the wal statistics for the cluster. */ + memset(&walStats, 0, sizeof(walStats)); + walStats.stat_reset_timestamp = GetCurrentTimestamp(); + } /* * Presumably the sender of this message validated the target, don't @@ -6427,6 +6528,18 @@ pgstat_recv_bgwriter(PgStat_MsgBgWriter *msg, int len) globalStats.buf_alloc += msg->m_buf_alloc; } +/* ---------- + * pgstat_recv_wal() - + * + * Process a WAL message. + * ---------- + */ +static void +pgstat_recv_wal(PgStat_MsgWal *msg, int len) +{ + walStats.wal_buffers_full += msg->m_wal_buffers_full; +} + /* ---------- * pgstat_recv_slru() - * diff --git a/src/backend/replication/logical/launcher.c b/src/backend/replication/logical/launcher.c index bdaf0312d6..23d7e2b537 100644 --- a/src/backend/replication/logical/launcher.c +++ b/src/backend/replication/logical/launcher.c @@ -1037,6 +1037,13 @@ ApplyLauncherMain(Datum main_arg) wait_time = wal_retrieve_retry_interval; } + /* + * Send wal statistics because some xlog may be written. + * It accesses the system table, which may cause HOT + * pruning or killing of dead index tuple. + */ + pgstat_send_wal(); + /* Wait for more work. */ rc = WaitLatch(MyLatch, WL_LATCH_SET | WL_TIMEOUT | WL_EXIT_ON_PM_DEATH, diff --git a/src/backend/replication/logical/worker.c b/src/backend/replication/logical/worker.c index d239d28c09..f580d8b01b 100644 --- a/src/backend/replication/logical/worker.c +++ b/src/backend/replication/logical/worker.c @@ -2200,6 +2200,13 @@ LogicalRepApplyLoop(XLogRecPtr last_received) MemoryContextResetAndDeleteChildren(ApplyMessageContext); MemoryContextSwitchTo(TopMemoryContext); + /* + * Send wal statistics because some xlog may be written. + * It accesses the system table, which may cause HOT + * pruning or killing of dead index tuple. + */ + pgstat_send_wal(); + /* Check if we need to exit the streaming loop. */ if (endofstream) { diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c index 7c9d1b67df..1180383531 100644 --- a/src/backend/replication/walsender.c +++ b/src/backend/replication/walsender.c @@ -2883,6 +2883,13 @@ XLogSendLogical(void) LogicalDecodingProcessRecord(logical_decoding_ctx, logical_decoding_ctx->reader); sentPtr = logical_decoding_ctx->reader->EndRecPtr; + + /* + * Send wal statistics because some xlog may be written. + * It accesses the system table, which may cause HOT + * pruning or killing of dead index tuple. + */ + pgstat_send_wal(); } /* diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c index 95738a4e34..aa41330796 100644 --- a/src/backend/utils/adt/pgstatfuncs.c +++ b/src/backend/utils/adt/pgstatfuncs.c @@ -1697,6 +1697,18 @@ pg_stat_get_buf_alloc(PG_FUNCTION_ARGS) PG_RETURN_INT64(pgstat_fetch_global()->buf_alloc); } +Datum +pg_stat_get_wal_buffers_full(PG_FUNCTION_ARGS) +{ + PG_RETURN_INT64(pgstat_fetch_stat_wal()->wal_buffers_full); +} + +Datum +pg_stat_get_wal_stat_reset_time(PG_FUNCTION_ARGS) +{ + PG_RETURN_TIMESTAMPTZ(pgstat_fetch_stat_wal()->stat_reset_timestamp); +} + /* * Returns statistics of SLRU caches. */ diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat index 96d7efd427..dde0cb55ce 100644 --- a/src/include/catalog/pg_proc.dat +++ b/src/include/catalog/pg_proc.dat @@ -5484,6 +5484,14 @@ proname => 'pg_stat_get_buf_alloc', provolatile => 's', proparallel => 'r', prorettype => 'int8', proargtypes => '', prosrc => 'pg_stat_get_buf_alloc' }, +{ oid => '1136', descr => 'statistics: number of WAL writes when the wal buffers are full', + proname => 'pg_stat_get_wal_buffers_full', provolatile => 's', proparallel => 'r', + prorettype => 'int8', proargtypes => '', prosrc => 'pg_stat_get_wal_buffers_full' }, +{ oid => '1137', descr => 'statistics: last reset for the walwriter', + proname => 'pg_stat_get_wal_stat_reset_time', provolatile => 's', + proparallel => 'r', prorettype => 'timestamptz', proargtypes => '', + prosrc => 'pg_stat_get_wal_stat_reset_time' }, + { oid => '2306', descr => 'statistics: information about SLRU caches', proname => 'pg_stat_get_slru', prorows => '100', proisstrict => 'f', proretset => 't', provolatile => 's', proparallel => 'r', diff --git a/src/include/pgstat.h b/src/include/pgstat.h index 0dfbac46b4..eb706068ba 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -61,6 +61,7 @@ typedef enum StatMsgType PGSTAT_MTYPE_ANALYZE, PGSTAT_MTYPE_ARCHIVER, PGSTAT_MTYPE_BGWRITER, + PGSTAT_MTYPE_WAL, PGSTAT_MTYPE_SLRU, PGSTAT_MTYPE_FUNCSTAT, PGSTAT_MTYPE_FUNCPURGE, @@ -122,7 +123,8 @@ typedef struct PgStat_TableCounts typedef enum PgStat_Shared_Reset_Target { RESET_ARCHIVER, - RESET_BGWRITER + RESET_BGWRITER, + RESET_WAL } PgStat_Shared_Reset_Target; /* Possible object types for resetting single counters */ @@ -436,6 +438,16 @@ typedef struct PgStat_MsgBgWriter PgStat_Counter m_checkpoint_sync_time; } PgStat_MsgBgWriter; +/* ---------- + * PgStat_MsgWal Sent by each backend and background workers to update WAL statistics. + * ---------- + */ +typedef struct PgStat_MsgWal +{ + PgStat_MsgHdr m_hdr; + PgStat_Counter m_wal_buffers_full; /* number of WAL write caused by full of WAL buffers */ +} PgStat_MsgWal; + /* ---------- * PgStat_MsgSLRU Sent by a backend to update SLRU statistics. * ---------- @@ -596,6 +608,7 @@ typedef union PgStat_Msg PgStat_MsgAnalyze msg_analyze; PgStat_MsgArchiver msg_archiver; PgStat_MsgBgWriter msg_bgwriter; + PgStat_MsgWal msg_wal; PgStat_MsgSLRU msg_slru; PgStat_MsgFuncstat msg_funcstat; PgStat_MsgFuncpurge msg_funcpurge; @@ -745,6 +758,15 @@ typedef struct PgStat_GlobalStats TimestampTz stat_reset_timestamp; } PgStat_GlobalStats; +/* + * WAL statistics kept in the stats collector + */ +typedef struct PgStat_WalStats +{ + PgStat_Counter wal_buffers_full; /* number of WAL write caused by full of WAL buffers */ + TimestampTz stat_reset_timestamp; /* last time when the stats reset */ +} PgStat_WalStats; + /* * SLRU statistics kept in the stats collector */ @@ -1265,6 +1287,11 @@ extern char *pgstat_stat_filename; */ extern PgStat_MsgBgWriter BgWriterStats; +/* + * WAL writes statistics counter is updated by backend and background workers + */ +extern PgStat_MsgWal WalStats; + /* * Updated by pgstat_count_buffer_*_time macros */ @@ -1464,6 +1491,7 @@ extern void pgstat_twophase_postabort(TransactionId xid, uint16 info, extern void pgstat_send_archiver(const char *xlog, bool failed); extern void pgstat_send_bgwriter(void); +extern void pgstat_send_wal(void); /* ---------- * Support functions for the SQL-callable functions to @@ -1478,6 +1506,7 @@ extern PgStat_StatFuncEntry *pgstat_fetch_stat_funcentry(Oid funcid); extern int pgstat_fetch_stat_numbackends(void); extern PgStat_ArchiverStats *pgstat_fetch_stat_archiver(void); extern PgStat_GlobalStats *pgstat_fetch_global(void); +extern PgStat_WalStats *pgstat_fetch_stat_wal(void); extern PgStat_SLRUStats *pgstat_fetch_slru(void); extern void pgstat_count_slru_page_zeroed(int slru_idx); diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out index 2a18dc423e..1e4ac4432e 100644 --- a/src/test/regress/expected/rules.out +++ b/src/test/regress/expected/rules.out @@ -2129,6 +2129,8 @@ pg_stat_user_tables| SELECT pg_stat_all_tables.relid, pg_stat_all_tables.autoanalyze_count FROM pg_stat_all_tables WHERE ((pg_stat_all_tables.schemaname <> ALL (ARRAY['pg_catalog'::name, 'information_schema'::name])) AND (pg_stat_all_tables.schemaname !~ '^pg_toast'::text)); +pg_stat_wal| SELECT pg_stat_get_wal_buffers_full() AS wal_buffers_full, + pg_stat_get_wal_stat_reset_time() AS stats_reset; pg_stat_wal_receiver| SELECT s.pid, s.status, s.receive_start_lsn, diff --git a/src/test/regress/expected/sysviews.out b/src/test/regress/expected/sysviews.out index 1cffc3349d..81bdacf59d 100644 --- a/src/test/regress/expected/sysviews.out +++ b/src/test/regress/expected/sysviews.out @@ -76,6 +76,13 @@ select count(*) >= 0 as ok from pg_prepared_xacts; t (1 row) +-- There must be only one record +select count(*) = 1 as ok from pg_stat_wal; + ok +---- + t +(1 row) + -- This is to record the prevailing planner enable_foo settings during -- a regression test run. select name, setting from pg_settings where name like 'enable%'; diff --git a/src/test/regress/sql/sysviews.sql b/src/test/regress/sql/sysviews.sql index ac4a0e1cbb..b9b875bc6a 100644 --- a/src/test/regress/sql/sysviews.sql +++ b/src/test/regress/sql/sysviews.sql @@ -37,6 +37,9 @@ select count(*) = 0 as ok from pg_prepared_statements; -- See also prepared_xacts.sql select count(*) >= 0 as ok from pg_prepared_xacts; +-- There must be only one record +select count(*) = 1 as ok from pg_stat_wal; + -- This is to record the prevailing planner enable_foo settings during -- a regression test run. select name, setting from pg_settings where name like 'enable%';