Horton

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

Peter Smith <smithpb2250@gmail.com>

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From: Peter Smith <smithpb2250@gmail.com>
To: Amit Kapila <amit.kapila16@gmail.com>
Cc: Nisha Moond <nisha.moond412@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>
Date: 2025-02-10T06:10:14Z
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

On Fri, Feb 7, 2025 at 4:53 PM Amit Kapila <amit.kapila16@gmail.com> wrote:
>
> On Fri, Feb 7, 2025 at 8:00 AM Peter Smith <smithpb2250@gmail.com> wrote:
> >
> > ======
> > src/backend/access/transam/xlog.c
> >
> > 1.
> >   XLByteToSeg(RedoRecPtr, _logSegNo, wal_segment_size);
> >   KeepLogSeg(recptr, &_logSegNo);
> > - if (InvalidateObsoleteReplicationSlots(RS_INVAL_WAL_REMOVED,
> > + if (InvalidateObsoleteReplicationSlots(RS_INVAL_WAL_REMOVED |
> > RS_INVAL_IDLE_TIMEOUT,
> >      _logSegNo, InvalidOid,
> >      InvalidTransactionId))
> >   {
> > @@ -7792,7 +7792,7 @@ CreateRestartPoint(int flags)
> >   replayPtr = GetXLogReplayRecPtr(&replayTLI);
> >   endptr = (receivePtr < replayPtr) ? replayPtr : receivePtr;
> >   KeepLogSeg(endptr, &_logSegNo);
> > - if (InvalidateObsoleteReplicationSlots(RS_INVAL_WAL_REMOVED,
> > + if (InvalidateObsoleteReplicationSlots(RS_INVAL_WAL_REMOVED |
> > RS_INVAL_IDLE_TIMEOUT,
> >      _logSegNo, InvalidOid,
> >      InvalidTransactionId))
> >
> > It seems fundamentally strange to me to assign multiple simultaneous
> > causes like this. IMO you can't invalidate something that is invalid
> > already. I gues v71 was an attempt to implement Amit's:
> >
>
> The idea is to invalidate the slot either due to WAL_REMOVED or
> IDLE_TIMEOUT in one go during the checkpoint instead of taking
> multiple passes over the slots during the checkpoint. Feel free to
> suggest if you can think of a better way to implement it.
>

Hi Amit,

My preference already suggested was to have a separation between the
concepts of *actual* causes (e.g. discrete enum values like in v70)
and *possible* causes to be checked (using #defines for bit flags).

My v72-0001 review [1] includes a top-up patch to show what doing it
this way might look like.

======
[1] https://www.postgresql.org/message-id/CAHut%2BPupn_S0mrM2zB%2BFwAbPqVak7jwSjRhU3WyA18QC1HU__g%40mail.gmail.com

Kind Regards,
Peter Smith.
Fujitsu Australia