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

Bertrand Drouvot <bertranddrouvot.pg@gmail.com>

From: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>

To: Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>

Cc: shveta malik <shveta.malik@gmail.com>, Masahiko Sawada <sawada.mshk@gmail.com>, Amit Kapila <amit.kapila16@gmail.com>, Nathan Bossart <nathandbossart@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>

Date: 2024-04-03T13:16:25Z

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 →

Add a test for commit ac0e33136a using the injection point.
- 8a695d7998be 18.0 landed
Invalidate inactive replication slots.
- ac0e33136abc 18.0 landed
Fix incorrect slot type in BuildTupleHashTableExt
- d96d1d5152f3 18.0 cited
Allow synced slots to have their inactive_since.
- 6f132ed693b6 17.0 landed
Change last_inactive_time to inactive_since in pg_replication_slots.
- 6d49c8d4b4f4 17.0 landed
Track last_inactive_time in pg_replication_slots.
- a11f330b5584 17.0 landed
Track invalidation_reason in pg_replication_slots.
- 6ae701b4378d 17.0 landed
Add option force_initdb to PostgreSQL::Test::Cluster:init()
- ff9e1e764fcc 17.0 cited
Add a failover option to subscriptions.
- 776621a5e479 17.0 cited
Allow setting failover property in the replication command.
- 73292404370c 17.0 cited
Allow to enable failover property for replication slots via SQL API.
- c393308b69d2 17.0 cited
Track conflict_reason in pg_replication_slots.
- 007693f2a3ac 17.0 cited
Log messages for replication slot acquisition and release.
- 7c3fb505b14e 17.0 cited
Remove vacuum_defer_cleanup_age
- 1118cd37eb61 16.0 cited
Fix corruption due to vacuum_defer_cleanup_age underflowing 64bit xids
- be504a3e974d 16.0 cited
meson: Add initial version of meson based build system
- e6927270cd18 16.0 cited

Hi,

On Wed, Apr 03, 2024 at 05:12:12PM +0530, Bharath Rupireddy wrote:
> On Wed, Apr 3, 2024 at 4:19 PM Amit Kapila <amit.kapila16@gmail.com> wrote:
> >
> > + 'postgres',
> > + "SELECT '$inactive_since_on_primary'::timestamptz <
> > '$inactive_since_on_standby'::timestamptz AND
> > + '$inactive_since_on_standby'::timestamptz < '$slot_sync_time'::timestamptz;"
> >
> > Shall we do <= check as we are doing in the main function
> > get_slot_inactive_since_value as the time duration is less so it can
> > be the same as well? Similarly, please check other tests.
> 
> I get you. If the tests are so fast that losing a bit of precision
> might cause tests to fail. So, I'v added equality check for all the
> tests.

> Please find the attached v32-0001 patch with the above review comments
> addressed.

Thanks!

Just one comment on v32-0001:

+# Synced slot on the standby must get its own inactive_since.
+is( $standby1->safe_psql(
+               'postgres',
+               "SELECT '$inactive_since_on_primary'::timestamptz <= '$inactive_since_on_standby'::timestamptz AND
+                       '$inactive_since_on_standby'::timestamptz <= '$slot_sync_time'::timestamptz;"
+       ),
+       "t",
+       'synchronized slot has got its own inactive_since');
+

By using <= we are not testing that it must get its own inactive_since (as we
allow them to be equal in the test). I think we should just add some usleep()
where appropriate and deny equality during the tests on inactive_since.

Except for the above, v32-0001 LGTM.

Regards,

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