From 0d39b5678617f1a454c8bed5b838287f988309fb Mon Sep 17 00:00:00 2001 From: Alexander Korotkov Date: Mon, 7 Sep 2026 13:38:17 +0300 Subject: [PATCH v2 3/3] Re-read standby LSN after recovery ends WaitForLSN() samples the current position before checking whether recovery is still in progress. If recovery reaches the target and ends between those operations, the promotion path can compare against the stale sample and incorrectly return NOT_IN_RECOVERY. Read the position again after observing that recovery has ended, before deciding whether promotion reached the target. Author: Xuneng Zhou Discussion: https://postgr.es/m/CABPTF7U0gW5%2B-4oL7-qdML-yerZxUb7ku4QXp7JxCYo0qyJ_Tw%40mail.gmail.com Reviewed-by: Alexander Korotkov Backpatch-through: 19 --- src/backend/access/transam/xlogwait.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/src/backend/access/transam/xlogwait.c b/src/backend/access/transam/xlogwait.c index c624f9163a1..fd3cac9103d 100644 --- a/src/backend/access/transam/xlogwait.c +++ b/src/backend/access/transam/xlogwait.c @@ -488,11 +488,19 @@ WaitForLSN(WaitLSNType lsnType, XLogRecPtr targetLSN, int64 timeout) if (WaitLSNTypeRequiresRecovery(lsnType) && !RecoveryInProgress()) { /* - * Recovery was ended, but check if target LSN was already + * Recovery has ended, but check if target LSN was already * reached. */ deleteLSNWaiter(lsnType); + /* + * Recovery may have advanced the current position after currentLSN + * was read above. Once RecoveryInProgress() returns false, the final + * position is stable, so read it again before deciding whether + * promotion reached the target. + */ + currentLSN = GetCurrentLSNForWaitType(lsnType); + if (PromoteIsTriggered() && targetLSN <= currentLSN) return WAIT_LSN_RESULT_SUCCESS; return WAIT_LSN_RESULT_NOT_IN_RECOVERY; -- 2.55.0