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: Nathan Bossart <nathandbossart@gmail.com>, Bertrand Drouvot <bertranddrouvot.pg@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2024-03-13T15:54:17Z
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 9:21 AM Amit Kapila <amit.kapila16@gmail.com> wrote:
>
> > So, how about we turn conflict_reason to only report the reasons that
> > actually cause conflict with recovery for logical slots, something
> > like below, and then have invalidation_cause as a generic column for
> > all sorts of invalidation reasons for both logical and physical slots?
>
> If our above understanding is correct then coflict_reason will be a
> subset of invalidation_reason. If so, whatever way we arrange this
> information, there will be some sort of duplicity unless we just have
> one column 'invalidation_reason' and update the docs to interpret it
> correctly for conflicts.

Yes, there will be some sort of duplicity if we emit conflict_reason
as a text field. However, I still think the better way is to turn
conflict_reason text to conflict boolean and set it to true only on
rows_removed and wal_level_insufficient invalidations. When conflict
boolean is true, one (including all the tests that we've added
recently) can look for invalidation_reason text field for the reason.
This sounds reasonable to me as opposed to we just mentioning in the
docs that "if invalidation_reason is rows_removed or
wal_level_insufficient it's the reason for conflict with recovery".

Thoughts?

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