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

shveta malik <shveta.malik@gmail.com>

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From: shveta malik <shveta.malik@gmail.com>
To: Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>
Cc: Peter Smith <smithpb2250@gmail.com>, Amit Kapila <amit.kapila16@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>, shveta malik <shveta.malik@gmail.com>
Date: 2024-09-18T09:19:00Z
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 Wed, Sep 18, 2024 at 12:21 PM shveta malik <shveta.malik@gmail.com> wrote:
>
> On Mon, Sep 16, 2024 at 3:31 PM Bharath Rupireddy
> <bharath.rupireddyforpostgres@gmail.com> wrote:
> >
> > Hi,
> >
> >
> > Please find the attached v46 patch having changes for the above review
> > comments and your test review comments and Shveta's review comments.
> >
>
> Thanks for addressing comments.
>
> Is there a reason that we don't support this invalidation on hot
> standby for non-synced slots? Shouldn't we support this time-based
> invalidation there too just like other invalidations?
>

Now since we are not changing inactive_since once it is invalidated,
we are not even initializing it during restart; and thus later when
someone tries to use slot, it leads to assert in
ReplicationSlotAcquire()  ( Assert(s->inactive_since > 0);

Steps:
--Disable logical subscriber and let the slot on publisher gets
invalidated due to inactive_timeout.
--Enable the logical subscriber again.
--Restart publisher.

a) We should initialize inactive_since when
ReplicationSlotSetInactiveSince() is called from RestoreSlotFromDisk()
even though it is invalidated.
b) And shall we mention in the doc of 'active_since', that once the
slot is invalidated, this value will remain unchanged until we
shutdown the server. On server restart, it is initialized to start
time. Thought?


thanks
Shveta