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

Amit Kapila <amit.kapila16@gmail.com>

From: Amit Kapila <amit.kapila16@gmail.com>
To: Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>
Cc: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>, Nathan Bossart <nathandbossart@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2024-03-23T05:57:20Z
Lists: pgsql-hackers

Commits

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  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 Sat, Mar 23, 2024 at 3:02 AM Bharath Rupireddy
<bharath.rupireddyforpostgres@gmail.com> wrote:
>
> On Fri, Mar 22, 2024 at 3:15 PM Bertrand Drouvot
> <bertranddrouvot.pg@gmail.com> wrote:
> >
> >
> > Worth to add some tests too (or we postpone them in future commits because we're
> > confident enough they will follow soon)?
>
> Yes. Added some tests in a new TAP test file named
> src/test/recovery/t/043_replslot_misc.pl. This new file can be used to
> add miscellaneous replication tests in future as well. I couldn't find
> a better place in existing test files - tried having the new tests for
> physical slots in t/001_stream_rep.pl and I didn't find a right place
> for logical slots.
>

How about adding the test in 019_replslot_limit? It is not a direct
fit but I feel later we can even add 'invalid_timeout' related tests
in this file which will use last_inactive_time feature. It is also
possible that some of the tests added by the 'invalid_timeout' feature
will obviate the need for some of these tests.

Review of v15
==============
1.
@@ -1026,7 +1026,8 @@ CREATE VIEW pg_replication_slots AS
             L.conflicting,
             L.invalidation_reason,
             L.failover,
-            L.synced
+            L.synced,
+            L.last_inactive_time
     FROM pg_get_replication_slots() AS L

As mentioned previously, let's keep these new fields before
conflicting and after two_phase.

2.
+# Get last_inactive_time value after slot's creation. Note that the
slot is still
+# inactive unless it's used by the standby below.
+my $last_inactive_time_1 = $primary->safe_psql('postgres',
+ qq(SELECT last_inactive_time FROM pg_replication_slots WHERE
slot_name = '$sb_slot' AND last_inactive_time IS NOT NULL;)
+);

We should check $last_inactive_time_1 to be a valid value and add a
similar check for logical slots.

3. BTW, why don't we set last_inactive_time for temporary slots
(RS_TEMPORARY) as well? Don't we even invalidate temporary slots? If
so, then I think we should set last_inactive_time for those as well
and later allow them to be invalidated based on timeout parameter.

-- 
With Regards,
Amit Kapila.