Horton

RE: Introduce XID age and inactive timeout based replication slot invalidation

Zhijie Hou (Fujitsu) <houzj.fnst@fujitsu.com>

View thread
From: "Zhijie Hou (Fujitsu)" <houzj.fnst@fujitsu.com>
To: Nisha Moond <nisha.moond412@gmail.com>
Cc: Amit Kapila <amit.kapila16@gmail.com>, vignesh C <vignesh21@gmail.com>, Shlok Kyal <shlok.kyal.oss@gmail.com>, "Hayato Kuroda (Fujitsu)" <kuroda.hayato@fujitsu.com>, shveta malik <shveta.malik@gmail.com>, Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>, Ajin Cherian <itsajin@gmail.com>, Bertrand Drouvot <bertranddrouvot.pg@gmail.com>, Masahiko Sawada <sawada.mshk@gmail.com>, Nathan Bossart <nathandbossart@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>, Peter Smith <smithpb2250@gmail.com>
Date: 2025-02-11T06:12:31Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Add a test for commit ac0e33136a using the injection point.

  2. Invalidate inactive replication slots.

  3. Fix incorrect slot type in BuildTupleHashTableExt

  4. Allow synced slots to have their inactive_since.

  5. Change last_inactive_time to inactive_since in pg_replication_slots.

  6. Track last_inactive_time in pg_replication_slots.

  7. Track invalidation_reason in pg_replication_slots.

  8. Add option force_initdb to PostgreSQL::Test::Cluster:init()

  9. Add a failover option to subscriptions.

  10. Allow setting failover property in the replication command.

  11. Allow to enable failover property for replication slots via SQL API.

  12. Track conflict_reason in pg_replication_slots.

  13. Log messages for replication slot acquisition and release.

  14. Remove vacuum_defer_cleanup_age

  15. Fix corruption due to vacuum_defer_cleanup_age underflowing 64bit xids

  16. meson: Add initial version of meson based build system

Attachments

On Monday, February 10, 2025 8:03 PM Nisha Moond <nisha.moond412@gmail.com> wrote:
> 
> On Sat, Feb 8, 2025 at 12:28 PM Zhijie Hou (Fujitsu) <houzj.fnst@fujitsu.com>
> wrote:
> >
> 
> > 3.
> >
> > +                       if (cause & RS_INVAL_HORIZON)
> > +                       {
> > +                               if (!SlotIsLogical(s))
> > +                                       goto invalidation_marked;
> >
> > I am not sure if this logic is correct. Even if the slot would not be
> > invalidated due to RS_INVAL_HORIZON, we should continue to check other
> causes.
> >
> 
> Used goto here since we do not expect RS_INVAL_HORIZON to be combined
> with any other "cause" and to keep the pgHead behavior.
> However, with the bitflag approach, the code should be future-safe, so
> replacing goto in v73 should handle this now.

I think the following logic needs some adjustments.

+			if (invalidation_cause == RS_INVAL_NONE &&
+				(possible_causes & RS_INVAL_HORIZON))
+			{
+				if (SlotIsLogical(s) &&
+				/* invalid DB oid signals a shared relation */
+					(dboid == InvalidOid || dboid == s->data.database) &&
+					TransactionIdIsValid(initial_effective_xmin) &&
+					TransactionIdPrecedesOrEquals(initial_effective_xmin,
+												  snapshotConflictHorizon))
+					invalidation_cause = RS_INVAL_HORIZON;
+				else if (TransactionIdIsValid(initial_catalog_effective_xmin) &&
+						 TransactionIdPrecedesOrEquals(initial_catalog_effective_xmin,
+													   snapshotConflictHorizon))
+					invalidation_cause = RS_INVAL_HORIZON;
+			}

I think we assign RS_INVAL_HORIZON to invalidation_cause only when the slot is
logical and the dboid is valid, but it is not guaranteed in the second if
condition ("else if (TransactionIdIsValid(initial_catalog_effective_xmin)").

Here is a top-up patch to fix this.

Best Regards,
Hou zj