rdelaage
/
postgresql
mirror of https://git.postgresql.org/git/postgresql.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Ignore invalidated slots while computing oldest catalog Xmin 

Once a logical slot has acquired a catalog_xmin, it doesn't let go of
it, even when invalidated by exceeding the max_slot_wal_keep_size, which
means that dead catalog tuples are not removed by vacuum anymore since
the point is invalidated, until the slot is dropped.  This could be
catastrophic if catalog churn is high.

Change the computation of Xmin to ignore invalidated slots,
to prevent dead rows from accumulating.

Backpatch to 13, where slot invalidation appeared.

Author: Sirisha Chamarthi <sirichamarthi22@gmail.com>
Reviewed-by: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>
Discussion: https://postgr.es/m/CAKrAKeUEDeqquN9vwzNeG-CN8wuVsfRYbeOUV9qKO_RHok=j+g@mail.gmail.com
This commit is contained in:
Alvaro Herrera 2022-11-22 10:56:07 +01:00
parent 385b317715
commit 1b3ed75714
No known key found for this signature in database
GPG Key ID: 1C20ACB9D5C564AE
2 changed files with 10 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
src/backend/replication/slot.c
View File

@ -778,6 +778,7 @@ ReplicationSlotsComputeRequiredXmin(bool already_locked)
ReplicationSlot *s = &ReplicationSlotCtl->replication_slots[i];
TransactionId effective_xmin;
TransactionId effective_catalog_xmin;
bool invalidated;
if (!s->in_use)
continue;
@ -785,8 +786,14 @@ ReplicationSlotsComputeRequiredXmin(bool already_locked)
SpinLockAcquire(&s->mutex);
effective_xmin = s->effective_xmin;
effective_catalog_xmin = s->effective_catalog_xmin;
invalidated = (!XLogRecPtrIsInvalid(s->data.invalidated_at) &&
XLogRecPtrIsInvalid(s->data.restart_lsn));
SpinLockRelease(&s->mutex);
/* invalidated slots need not apply */
if (invalidated)
continue;
/* check the data xmin */
if (TransactionIdIsValid(effective_xmin) &&
(!TransactionIdIsValid(agg_xmin) ||

3
src/backend/storage/ipc/procarray.c
View File

@ -3946,6 +3946,9 @@ ProcArraySetReplicationSlotXmin(TransactionId xmin, TransactionId catalog_xmin,
if (!already_locked)
LWLockRelease(ProcArrayLock);
elog(DEBUG1, "xmin required by slots: data %u, catalog %u",
xmin, catalog_xmin);
}
/*