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: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Cc: Amit Kapila <amit.kapila16@gmail.com>, Nathan Bossart <nathandbossart@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2024-03-13T16:36:27Z
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, Mar 13, 2024 at 12:51 PM Bertrand Drouvot
<bertranddrouvot.pg@gmail.com> wrote:
>
> See the error messages on a standby:
>
> == wal removal
>
> postgres=#  SELECT * FROM pg_logical_slot_get_changes('lsub4_slot', NULL, NULL, 'include-xids', '0');
> ERROR:  can no longer get changes from replication slot "lsub4_slot"
> DETAIL:  This slot has been invalidated because it exceeded the maximum reserved size.
>
> == wal level
>
> postgres=# select conflict_reason from pg_replication_slots where slot_name = 'lsub5_slot';;
>     conflict_reason
> ------------------------
>  wal_level_insufficient
> (1 row)
>
> postgres=#  SELECT * FROM pg_logical_slot_get_changes('lsub5_slot', NULL, NULL, 'include-xids', '0');
> ERROR:  can no longer get changes from replication slot "lsub5_slot"
> DETAIL:  This slot has been invalidated because it was conflicting with recovery.
>
> == rows removal
>
> postgres=# select conflict_reason from pg_replication_slots where slot_name = 'lsub6_slot';;
>  conflict_reason
> -----------------
>  rows_removed
> (1 row)
>
> postgres=#  SELECT * FROM pg_logical_slot_get_changes('lsub6_slot', NULL, NULL, 'include-xids', '0');
> ERROR:  can no longer get changes from replication slot "lsub6_slot"
> DETAIL:  This slot has been invalidated because it was conflicting with recovery.
>
> As you can see, only wal level and rows removal are mentioning conflict with
> recovery.
>
> So, are we already "wrong" mentioning "wal_removed" in conflict_reason?

It looks like yes. So, how about we fix it the way proposed here -
https://www.postgresql.org/message-id/CALj2ACVd_dizYQiZwwUfsb%2BhG-fhGYo_kEDq0wn_vNwQvOrZHg%40mail.gmail.com?

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