database/postgres
database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-05-28 05:21:27 +03:00
Code

Fix synchronized_standby_slots GUC check hook

Browse Source 
The validate_sync_standby_slots subroutine requires an LWLock, so it
cannot run in processes without PGPROC; skip it there to avoid a crash.

This replaces the current test for ReplicationSlotCtl being not null,
which appears to be a solution for the same problem but less general.
I also rewrote a related comment that mentioned ReplicationSlotCtl in
StandbySlotsHaveCaughtup.

This code came in with commit bf279ddd1c28; backpatch to 17.

Reported-by: Gabriele Bartolini <gabriele.bartolini@enterprisedb.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Reviewed-by: Zhijie Hou <houzj.fnst@fujitsu.com>
Discussion: https://postgr.es/m/202411281216.sutbxtr6idnn@alvherre.pgsql
This commit is contained in:
Álvaro Herrera 2024-12-03 17:50:57 +01:00
parent 5ffbbcfa16
commit 9abdc1841e
No known key found for this signature in database
GPG Key ID: 1C20ACB9D5C564AE
1 changed files with 17 additions and 27 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

44
src/backend/replication/slot.c
View File

@ -2428,18 +2428,15 @@ validate_sync_standby_slots(char *rawname, List **elemlist)
{
GUC_check_errdetail("List syntax is invalid.");
}
else if (!ReplicationSlotCtl)
else if (MyProc)
{
/*
* We cannot validate the replication slot if the replication slots'
* data has not been initialized. This is ok as we will anyway
* validate the specified slot when waiting for them to catch up. See
* StandbySlotsHaveCaughtup() for details.
* Check that each specified slot exist and is physical.
*
* Because we need an LWLock, we cannot do this on processes without a
* PGPROC, so we skip it there; but see comments in
* StandbySlotsHaveCaughtup() as to why that's not a problem.
*/
}
else
{
/* Check that the specified slots exist and are logical slots */
LWLockAcquire(ReplicationSlotControlLock, LW_SHARED);
foreach_ptr(char, name, *elemlist)
@ -2621,18 +2618,18 @@ StandbySlotsHaveCaughtup(XLogRecPtr wait_for_lsn, int elevel)
slot = SearchNamedReplicationSlot(name, false);
/*
* If a slot name provided in synchronized_standby_slots does not
* exist, report a message and exit the loop.
*
* Though validate_sync_standby_slots (the GUC check_hook) tries to
* avoid this, it can nonetheless happen because the user can specify
* a nonexistent slot name before server startup. That function cannot
* validate such a slot during startup, as ReplicationSlotCtl is not
* initialized by then. Also, the user might have dropped one slot.
*/
if (!slot)
{
/*
* If a slot name provided in synchronized_standby_slots does not
* exist, report a message and exit the loop. A user can specify a
* slot name that does not exist just before the server startup.
* The GUC check_hook(validate_sync_standby_slots) cannot validate
* such a slot during startup as the ReplicationSlotCtl shared
* memory is not initialized at that time. It is also possible for
* a user to drop the slot in synchronized_standby_slots
* afterwards.
*/
ereport(elevel,
errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("replication slot \"%s\" specified in parameter \"%s\" does not exist",
@ -2644,16 +2641,9 @@ StandbySlotsHaveCaughtup(XLogRecPtr wait_for_lsn, int elevel)
break;
}
/* Same as above: if a slot is not physical, exit the loop. */
if (SlotIsLogical(slot))
{
/*
* If a logical slot name is provided in
* synchronized_standby_slots, report a message and exit the loop.
* Similar to the non-existent case, a user can specify a logical
* slot name in synchronized_standby_slots before the server
* startup, or drop an existing physical slot and recreate a
* logical slot with the same name.
*/
ereport(elevel,
errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("cannot specify logical replication slot \"%s\" in parameter \"%s\"",