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

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(dot)kapila16(at)gmail(dot)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