From eb124c3d6deb5d0c7a588d847e3840bcc2cd0dcc Mon Sep 17 00:00:00 2001 From: Alexander Korotkov Date: Sat, 14 Jun 2025 03:35:27 +0300 Subject: Add TAP tests to check replication slot advance during the checkpoint The new tests verify that logical and physical replication slots are still valid after an immediate restart on checkpoint completion when the slot was advanced during the checkpoint. This commit introduces two new injection points to make these tests possible: * checkpoint-before-old-wal-removal - triggered in the checkpointer process just before old WAL segments cleanup; * logical-replication-slot-advance-segment - triggered in LogicalConfirmReceivedLocation() when restart_lsn was changed enough to point to the next WAL segment. Discussion: https://postgr.es/m/flat/1d12d2-67235980-35-19a406a0%4063439497 Author: Vitaly Davydov Author: Tomas Vondra Reviewed-by: Alexander Korotkov Reviewed-by: Amit Kapila Backpatch-through: 17 --- src/backend/access/transam/xlog.c | 4 ++++ src/backend/replication/logical/logical.c | 18 ++++++++++++++++++ 2 files changed, 22 insertions(+) (limited to 'src/backend') diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 1914859b2ee..47ffc0a2307 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -7498,6 +7498,10 @@ CreateCheckPoint(int flags) if (PriorRedoPtr != InvalidXLogRecPtr) UpdateCheckPointDistanceEstimate(RedoRecPtr - PriorRedoPtr); +#ifdef USE_INJECTION_POINTS + INJECTION_POINT("checkpoint-before-old-wal-removal", NULL); +#endif + /* * Delete old log files, those no longer needed for last checkpoint to * prevent the disk holding the xlog from growing full. diff --git a/src/backend/replication/logical/logical.c b/src/backend/replication/logical/logical.c index 1d56d0c4ef3..f1eb798f3e9 100644 --- a/src/backend/replication/logical/logical.c +++ b/src/backend/replication/logical/logical.c @@ -29,6 +29,7 @@ #include "postgres.h" #include "access/xact.h" +#include "access/xlog_internal.h" #include "access/xlogutils.h" #include "fmgr.h" #include "miscadmin.h" @@ -41,6 +42,7 @@ #include "storage/proc.h" #include "storage/procarray.h" #include "utils/builtins.h" +#include "utils/injection_point.h" #include "utils/inval.h" #include "utils/memutils.h" @@ -1825,9 +1827,13 @@ LogicalConfirmReceivedLocation(XLogRecPtr lsn) { bool updated_xmin = false; bool updated_restart = false; + XLogRecPtr restart_lsn pg_attribute_unused(); SpinLockAcquire(&MyReplicationSlot->mutex); + /* remember the old restart lsn */ + restart_lsn = MyReplicationSlot->data.restart_lsn; + /* * Prevent moving the confirmed_flush backwards, as this could lead to * data duplication issues caused by replicating already replicated @@ -1881,6 +1887,18 @@ LogicalConfirmReceivedLocation(XLogRecPtr lsn) /* first write new xmin to disk, so we know what's up after a crash */ if (updated_xmin || updated_restart) { +#ifdef USE_INJECTION_POINTS + XLogSegNo seg1, + seg2; + + XLByteToSeg(restart_lsn, seg1, wal_segment_size); + XLByteToSeg(MyReplicationSlot->data.restart_lsn, seg2, wal_segment_size); + + /* trigger injection point, but only if segment changes */ + if (seg1 != seg2) + INJECTION_POINT("logical-replication-slot-advance-segment", NULL); +#endif + ReplicationSlotMarkDirty(); ReplicationSlotSave(); elog(DEBUG1, "updated xmin: %u restart: %u", updated_xmin, updated_restart); -- cgit v1.2.3