From bc93177ca524c1a2e0e67b2697143fc1ffe326d5 Mon Sep 17 00:00:00 2001 From: alterego655 <824662526@qq.com> Date: Tue, 27 Jan 2026 14:02:52 +0800 Subject: [PATCH v1 4/4] Add wal_source column to pg_stat_recovery Extend pg_stat_recovery with a wal_source column that shows where the startup process most recently read WAL data from: 'archive', 'pg_wal', or 'stream'. This helps diagnose recovery behavior: - Detecting streaming vs archive fallback transitions - Monitoring initial standby catch-up progress - Troubleshooting replication lag sources The column reflects the current read source, not the original delivery mechanism. Streamed WAL that is subsequently read from local files shows 'pg_wal'. NULL if no WAL has been read yet. --- doc/src/sgml/monitoring.sgml | 36 +++++++++++++++++++++++ src/backend/access/transam/xlogfuncs.c | 21 ++++++++++++- src/backend/access/transam/xlogrecovery.c | 6 ++++ src/backend/catalog/system_views.sql | 3 +- src/include/access/xlogrecovery.h | 8 +++++ src/include/catalog/pg_proc.dat | 6 ++-- src/test/regress/expected/rules.out | 5 ++-- 7 files changed, 78 insertions(+), 7 deletions(-) diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml index ac2cb309976..09e341639e9 100644 --- a/doc/src/sgml/monitoring.sgml +++ b/doc/src/sgml/monitoring.sgml @@ -2062,6 +2062,42 @@ description | Waiting for a newly initialized WAL file to reach durable storage + + + wal_source text + + + Source from which the startup process most recently read WAL data. + Possible values are: + + + + + archive: WAL restored using + restore_command. + + + + + pg_wal: WAL read from local + pg_wal directory. + + + + + stream: WAL actively being streamed from the + upstream server. + + + + + NULL if no WAL has been read yet. Note that this reflects the + current read source, not the original delivery mechanism; streamed + WAL that is subsequently read from local files will show + pg_wal. + + + diff --git a/src/backend/access/transam/xlogfuncs.c b/src/backend/access/transam/xlogfuncs.c index 330bf00f6d9..1117a46a48e 100644 --- a/src/backend/access/transam/xlogfuncs.c +++ b/src/backend/access/transam/xlogfuncs.c @@ -765,7 +765,7 @@ pg_promote(PG_FUNCTION_ARGS) Datum pg_stat_get_recovery(PG_FUNCTION_ARGS) { -#define PG_STAT_GET_RECOVERY_COLS 9 +#define PG_STAT_GET_RECOVERY_COLS 10 ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo; Datum values[PG_STAT_GET_RECOVERY_COLS]; bool nulls[PG_STAT_GET_RECOVERY_COLS]; @@ -781,6 +781,7 @@ pg_stat_get_recovery(PG_FUNCTION_ARGS) TimestampTz recovery_last_xact_time; TimestampTz current_chunk_start_time; RecoveryPauseState pause_state; + XLogSource wal_source; InitMaterializedSRF(fcinfo, 0); @@ -805,6 +806,7 @@ pg_stat_get_recovery(PG_FUNCTION_ARGS) recovery_last_xact_time = XLogRecoveryCtl->recoveryLastXTime; current_chunk_start_time = XLogRecoveryCtl->currentChunkStartTime; pause_state = XLogRecoveryCtl->recoveryPauseState; + wal_source = XLogRecoveryCtl->lastReadSource; SpinLockRelease(&XLogRecoveryCtl->info_lck); /* Initialize nulls array */ @@ -887,6 +889,23 @@ pg_stat_get_recovery(PG_FUNCTION_ARGS) break; } + /* wal_source - always visible */ + switch (wal_source) + { + case XLOG_FROM_ANY: + nulls[9] = true; /* not yet determined */ + break; + case XLOG_FROM_ARCHIVE: + values[9] = CStringGetTextDatum("archive"); + break; + case XLOG_FROM_PG_WAL: + values[9] = CStringGetTextDatum("pg_wal"); + break; + case XLOG_FROM_STREAM: + values[9] = CStringGetTextDatum("stream"); + break; + } + tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc, values, nulls); return (Datum) 0; diff --git a/src/backend/access/transam/xlogrecovery.c b/src/backend/access/transam/xlogrecovery.c index 9fdf143d18f..af86eece08c 100644 --- a/src/backend/access/transam/xlogrecovery.c +++ b/src/backend/access/transam/xlogrecovery.c @@ -397,6 +397,7 @@ XLogRecoveryShmemInit(void) memset(XLogRecoveryCtl, 0, sizeof(XLogRecoveryCtlData)); SpinLockInit(&XLogRecoveryCtl->info_lck); + XLogRecoveryCtl->lastReadSource = XLOG_FROM_ANY; InitSharedLatch(&XLogRecoveryCtl->recoveryWakeupLatch); ConditionVariableInit(&XLogRecoveryCtl->recoveryNotPausedCV); } @@ -4246,6 +4247,11 @@ XLogFileRead(XLogSegNo segno, TimeLineID tli, if (source != XLOG_FROM_STREAM) XLogReceiptTime = GetCurrentTimestamp(); + /* Update shared memory for external visibility */ + SpinLockAcquire(&XLogRecoveryCtl->info_lck); + XLogRecoveryCtl->lastReadSource = source; + SpinLockRelease(&XLogRecoveryCtl->info_lck); + return fd; } if (errno != ENOENT || !notfoundOk) /* unexpected failure? */ diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql index a88cac599c4..36182cb5057 100644 --- a/src/backend/catalog/system_views.sql +++ b/src/backend/catalog/system_views.sql @@ -994,7 +994,8 @@ CREATE VIEW pg_stat_recovery AS s.replay_end_tli, s.recovery_last_xact_time, s.current_chunk_start_time, - s.pause_state + s.pause_state, + s.wal_source FROM pg_stat_get_recovery() s; CREATE VIEW pg_stat_recovery_prefetch AS diff --git a/src/include/access/xlogrecovery.h b/src/include/access/xlogrecovery.h index 514595f0ee6..f18922271a1 100644 --- a/src/include/access/xlogrecovery.h +++ b/src/include/access/xlogrecovery.h @@ -133,6 +133,14 @@ typedef struct XLogRecoveryCtlData RecoveryPauseState recoveryPauseState; ConditionVariable recoveryNotPausedCV; + /* + * Source from which the startup process most recently read WAL data. + * Updated when the startup process successfully reads WAL from a source. + * Note: this reflects the read source, not the original receipt source; + * streamed WAL read from local files will show XLOG_FROM_PG_WAL. + */ + XLogSource lastReadSource; + slock_t info_lck; /* locks shared variables shown above */ } XLogRecoveryCtlData; diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat index 3b1569d8a3f..d86de7901da 100644 --- a/src/include/catalog/pg_proc.dat +++ b/src/include/catalog/pg_proc.dat @@ -5701,9 +5701,9 @@ proname => 'pg_stat_get_recovery', prorows => '1', proretset => 't', provolatile => 's', proparallel => 'r', prorettype => 'record', proargtypes => '', - proallargtypes => '{bool,pg_lsn,pg_lsn,int4,pg_lsn,int4,timestamptz,timestamptz,text}', - proargmodes => '{o,o,o,o,o,o,o,o,o}', - proargnames => '{promote_triggered,last_replayed_read_lsn,last_replayed_end_lsn,last_replayed_tli,replay_end_lsn,replay_end_tli,recovery_last_xact_time,current_chunk_start_time,pause_state}', + proallargtypes => '{bool,pg_lsn,pg_lsn,int4,pg_lsn,int4,timestamptz,timestamptz,text,text}', + proargmodes => '{o,o,o,o,o,o,o,o,o,o}', + proargnames => '{promote_triggered,last_replayed_read_lsn,last_replayed_end_lsn,last_replayed_tli,replay_end_lsn,replay_end_tli,recovery_last_xact_time,current_chunk_start_time,pause_state,wal_source}', prosrc => 'pg_stat_get_recovery' }, { oid => '6169', descr => 'statistics: information about replication slot', proname => 'pg_stat_get_replication_slot', provolatile => 's', diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out index 7f3499291b5..81f11329b6f 100644 --- a/src/test/regress/expected/rules.out +++ b/src/test/regress/expected/rules.out @@ -2135,8 +2135,9 @@ pg_stat_recovery| SELECT promote_triggered, replay_end_tli, recovery_last_xact_time, current_chunk_start_time, - pause_state - FROM pg_stat_get_recovery() s(promote_triggered, last_replayed_read_lsn, last_replayed_end_lsn, last_replayed_tli, replay_end_lsn, replay_end_tli, recovery_last_xact_time, current_chunk_start_time, pause_state); + pause_state, + wal_source + FROM pg_stat_get_recovery() s(promote_triggered, last_replayed_read_lsn, last_replayed_end_lsn, last_replayed_tli, replay_end_lsn, replay_end_tli, recovery_last_xact_time, current_chunk_start_time, pause_state, wal_source); pg_stat_recovery_prefetch| SELECT stats_reset, prefetch, hit, -- 2.51.0