diff options
Diffstat (limited to 'src/backend/replication')
| -rw-r--r-- | src/backend/replication/logical/logical.c | 10 | ||||
| -rw-r--r-- | src/backend/replication/walsender.c | 4 |
2 files changed, 13 insertions, 1 deletions
diff --git a/src/backend/replication/logical/logical.c b/src/backend/replication/logical/logical.c index 74e22fff78d..e9105edaef5 100644 --- a/src/backend/replication/logical/logical.c +++ b/src/backend/replication/logical/logical.c @@ -1803,7 +1803,15 @@ LogicalConfirmReceivedLocation(XLogRecPtr lsn) SpinLockRelease(&MyReplicationSlot->mutex); - /* first write new xmin to disk, so we know what's up after a crash */ + /* + * First, write new xmin and restart_lsn to disk so we know what's up + * after a crash. Even when we do this, the checkpointer can see the + * updated restart_lsn value in the shared memory; then, a crash can + * happen before we manage to write that value to the disk. Thus, + * checkpointer still needs to make special efforts to keep WAL + * segments required by the restart_lsn written to the disk. See + * CreateCheckPoint() and CreateRestartPoint() for details. + */ if (updated_xmin || updated_restart) { ReplicationSlotMarkDirty(); diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c index 4bd4bb7aa0d..a72424a861e 100644 --- a/src/backend/replication/walsender.c +++ b/src/backend/replication/walsender.c @@ -2065,6 +2065,10 @@ PhysicalConfirmReceivedLocation(XLogRecPtr lsn) * be energy wasted - the worst lost information can do here is give us * wrong information in a statistics view - we'll just potentially be more * conservative in removing files. + * + * Checkpointer makes special efforts to keep the WAL segments required by + * the restart_lsn written to the disk. See CreateCheckPoint() and + * CreateRestartPoint() for details. */ } |