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

shveta malik <shveta.malik@gmail.com>

From: shveta malik <shveta.malik@gmail.com>
To: Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>
Cc: Amit Kapila <amit.kapila16@gmail.com>, Bertrand Drouvot <bertranddrouvot.pg@gmail.com>, Nathan Bossart <nathandbossart@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>, shveta malik <shveta.malik@gmail.com>
Date: 2024-03-25T06:23:53Z
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, Mar 25, 2024 at 10:33 AM shveta malik <shveta.malik@gmail.com> wrote:
>
> On Sun, Mar 24, 2024 at 3:06 PM Bharath Rupireddy
> <bharath.rupireddyforpostgres@gmail.com> wrote:
> >
> > I've attached the v18 patch set here.
>

I have a question. Don't we allow creating subscriptions on an
existing slot with a non-null 'inactive_timeout' set where
'inactive_timeout' of the slot is retained even after subscription
creation?

I tried this:

===================
--On publisher, create slot with 120sec inactive_timeout:
SELECT * FROM pg_create_logical_replication_slot('logical_slot1',
'pgoutput', false, true, true, 120);

--On subscriber, create sub using logical_slot1
create subscription mysubnew1_1  connection 'dbname=newdb1
host=localhost user=shveta port=5433' publication mypubnew1_1 WITH
(failover = true, create_slot=false, slot_name='logical_slot1');

--Before creating sub, pg_replication_slots output:
   slot_name   | failover | synced | active | temp | conf |
   lat                | inactive_timeout
---------------+----------+--------+--------+------+------+----------------------------------+------------------
 logical_slot1 | t        | f      | f      | f    | f    | 2024-03-25
11:11:55.375736+05:30 |              120

--After creating sub pg_replication_slots output:  (inactive_timeout is 0 now):
   slot_name   |failover | synced | active | temp | conf | | lat |
inactive_timeout
---------------+---------+--------+--------+------+------+-+-----+------------------
 logical_slot1 |t        | f      | t      | f    | f    | |     |
           0
===================

In CreateSubscription, we call  'walrcv_alter_slot()' /
'ReplicationSlotAlter()' when create_slot is false. This call ends up
setting active_timeout from 120sec to 0. Is it intentional?

thanks
Shveta