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

Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>

From: Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>
To: Amit Kapila <amit.kapila16@gmail.com>
Cc: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>, Nathan Bossart <nathandbossart@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2024-03-12T15:44:40Z
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 Tue, Mar 12, 2024 at 5:51 PM Amit Kapila <amit.kapila16@gmail.com> wrote:
>
> > Would that make sense to "simply" discard/prevent those kind of invalidations
> > for "synced" slot on standby? I mean, do they make sense given the fact that
> > those slots are not usable until the standby is promoted?
>
> AFAIR, we don't prevent similar invalidations due to
> 'max_slot_wal_keep_size' for sync slots, so why to prevent it for
> these new parameters? This will unnecessarily create inconsistency in
> the invalidation behavior.

Right. +1 to keep the behaviour consistent for all invalidations.
However, an assertion that inactive_timeout isn't set for synced slots
on the standby isn't a bad idea because we rely on the fact that
walsenders aren't started for synced slots. Again, I think it misses
the consistency in the invalidation behaviour.

--
Bharath Rupireddy
PostgreSQL Contributors Team
RDS Open Source Databases
Amazon Web Services: https://aws.amazon.com