Checkpoint replication slots later in the checkpoint cycle Previously, CheckPointReplicationSlots() ran at the start of CheckPointGuts(), while WAL cleanup occurred much later in CreateCheckPoint() and CreateRestartPoint(), after the buffer write and ProcessSyncRequests() phases. During a spread checkpoint, this gap could be several minutes.
During that time, active replication slots could advance their restart_lsn. However, replicationSlotMinLSN had already been computed from the older saved values. As a result, KeepLogSeg() could retain WAL segments that were no longer needed, causing unnecessary pg_wal growth until the next checkpoint or restartpoint. Fix this by moving CheckPointReplicationSlots(), CheckPointSnapBuild(), and CheckPointLogicalRewriteHeap() to just before CheckPointTwoPhase(), after the buffer write and ProcessSyncRequests() phases. This makes WAL retention decisions use the latest replication slot state. The logical snapshot and rewrite heap cleanup decisions also benefit from the updated saved restart_lsn. Author: Ants Aasma <[email protected]> Author: Hüseyin Demir <[email protected]> Reviewed-by: Fujii Masao <[email protected]> Discussion: https://postgr.es/m/CANwKhkPCBcTQ_pk06MD5W5YYNnuYHp8dLNuOUz8-5pMBMPY1Bw%40mail.gmail.com Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/69ed7fd7e9da1cff2f04af04f630287971fe99fe Modified Files -------------- src/backend/access/transam/xlog.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-)
