database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-06-30 21:42:05 +03:00
Code Activity

Block replication slot advance for these not yet reserving WAL

Browse Source 
Such replication slots are physical slots freshly created without WAL
being reserved, which is the default behavior, which have not been used
yet as WAL consumption resources to retain WAL.  This prevents advancing
a slot to a position older than any WAL available, which could falsify
calculations for WAL segment recycling.

This also cleans up a bit the code, as ReplicationSlotRelease() would be
called on ERROR, and improves error messages.

Reported-by: Kyotaro Horiguchi
Author: Michael Paquier
Reviewed-by: Andres Freund, Álvaro Herrera, Kyotaro Horiguchi
Discussion: https://postgr.es/m/20180626071305.GH31353@paquier.xyz
This commit is contained in:
Michael Paquier
2018-07-11 08:57:18 +09:00
parent e7df94f317
commit 9069eb95f4
4 changed files with 33 additions and 6 deletions
Download Patch File Download Diff File Expand all files Collapse all files

13
src/backend/replication/slotfuncs.c
View File

@ -483,6 +483,12 @@ pg_replication_slot_advance(PG_FUNCTION_ARGS)
/* Acquire the slot so we "own" it */
ReplicationSlotAcquire(NameStr(*slotname), true);
/* A slot whose restart_lsn has never been reserved cannot be advanced */
if (XLogRecPtrIsInvalid(MyReplicationSlot->data.restart_lsn))
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("cannot advance replication slot that has not previously reserved WAL")));
/*
* Check if the slot is not moving backwards. Physical slots rely simply
* on restart_lsn as a minimum point, while logical slots have confirmed
@ -495,14 +501,11 @@ pg_replication_slot_advance(PG_FUNCTION_ARGS)
minlsn = MyReplicationSlot->data.restart_lsn;
if (moveto < minlsn)
{
ReplicationSlotRelease();
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot move slot to %X/%X, minimum is %X/%X",
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("cannot advance replication slot to %X/%X, minimum is %X/%X",
(uint32) (moveto >> 32), (uint32) moveto,
(uint32) (minlsn >> 32), (uint32) minlsn)));
}
/* Do the actual slot update, depending on the slot type */
if (OidIsValid(MyReplicationSlot->data.database))