From a37a7bfb05d9066676647ade0ecff85ee5cda2c4 Mon Sep 17 00:00:00 2001 From: Kyotaro Horiguchi Date: Thu, 9 Jun 2016 14:56:07 +0900 Subject: [PATCH] Make pg_stop_backup on standby give proper end LSN. pg_basebackup to a replication standby can fail with an error that says no WAL available. This is caused by that the do_pg_stop_backup returns the minRecoveryPoint as the backup end point but it is sometimes too small, that is, going behind backup start point given by do_pg_start_backup. We use lastReplayedEndRecPtr instead. It is the last LSN that may be affect page files on disk, which is suitable for this use. --- src/backend/access/transam/xlog.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index b473f19..438b091 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -10409,9 +10409,9 @@ do_pg_stop_backup(char *labelfile, bool waitforarchive, TimeLineID *stoptli_p) * required files are available, a user should wait for them to be * archived, or include them into the backup. * - * We return the current minimum recovery point as the backup end + * We return the current last replayed point as the backup end * location. Note that it can be greater than the exact backup end - * location if the minimum recovery point is updated after the backup of + * location if the last replayed point is updated after the backup of * pg_control. This is harmless for current uses. * * XXX currently a backup history file is for informational and debug @@ -10430,6 +10430,8 @@ do_pg_stop_backup(char *labelfile, bool waitforarchive, TimeLineID *stoptli_p) */ SpinLockAcquire(&XLogCtl->info_lck); recptr = XLogCtl->lastFpwDisableRecPtr; + stoppoint = XLogCtl->lastReplayedEndRecPtr; + stoptli = XLogCtl->lastReplayedTLI; SpinLockRelease(&XLogCtl->info_lck); if (startpoint <= recptr) @@ -10442,12 +10444,6 @@ do_pg_stop_backup(char *labelfile, bool waitforarchive, TimeLineID *stoptli_p) "Enable full_page_writes and run CHECKPOINT on the master, " "and then try an online backup again."))); - - LWLockAcquire(ControlFileLock, LW_SHARED); - stoppoint = ControlFile->minRecoveryPoint; - stoptli = ControlFile->minRecoveryPointTLI; - LWLockRelease(ControlFileLock); - if (stoptli_p) *stoptli_p = stoptli; return stoppoint; -- 1.8.3.1