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

Amit Kapila <amit.kapila16@gmail.com>

From: Amit Kapila <amit.kapila16@gmail.com>
To: Shlok Kyal <shlok.kyal.oss@gmail.com>
Cc: Nisha Moond <nisha.moond412@gmail.com>, Peter Smith <smithpb2250@gmail.com>, vignesh C <vignesh21@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: 2025-02-04T05:15:09Z
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 Mon, Feb 3, 2025 at 6:35 PM Shlok Kyal <shlok.kyal.oss@gmail.com> wrote:
>
> I reviewed the v66 patch. I have few comments:
>
> 1. I also feel the default value should be set to '0' as suggested by
> Vignesh in 1st point of [1].
>

+1. This will ensure that the idle slots won't be invalidated by
default, the same as HEAD. We can change the default value based on
user inputs.

> 2. Should we allow copying of invalidated slots?
> Currently we are able to copy slots which are invalidated:
>
> postgres=# select slot_name, active, restart_lsn, wal_status,
> inactive_since , invalidation_reason from pg_replication_slots;
>  slot_name | active | restart_lsn | wal_status |
> inactive_since          | invalidation_reason
> -----------+--------+-------------+------------+----------------------------------+---------------------
>  test1     | f      | 0/16FDDE0   | lost       | 2025-02-03
> 18:28:01.802463+05:30 | idle_timeout
> (1 row)
>
> postgres=# select pg_copy_logical_replication_slot('test1', 'test2');
>  pg_copy_logical_replication_slot
> ----------------------------------
>  (test2,0/16FDE18)
> (1 row)
>
> postgres=# select slot_name, active, restart_lsn, wal_status,
> inactive_since , invalidation_reason from pg_replication_slots;
>  slot_name | active | restart_lsn | wal_status |
> inactive_since          | invalidation_reason
> -----------+--------+-------------+------------+----------------------------------+---------------------
>  test1     | f      | 0/16FDDE0   | lost       | 2025-02-03
> 18:28:01.802463+05:30 | idle_timeout
>  test2     | f      | 0/16FDDE0   | reserved   | 2025-02-03
> 18:29:53.478023+05:30 |
> (2 rows)
>

Is this related to this patch or the behavior of HEAD? If this
behavior is not introduced by this patch then we should discuss this
in a separate thread. I couldn't think of why anyone wants to copy the
invalid slots, so we should probably prohibit copying invalid slots
but that is a matter of separate discussion unless introduced by this
patch.

-- 
With Regards,
Amit Kapila.