Horton

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

Amit Kapila <amit.kapila16@gmail.com>

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From: Amit Kapila <amit.kapila16@gmail.com>
To: "Zhijie Hou (Fujitsu)" <houzj.fnst@fujitsu.com>
Cc: Nisha Moond <nisha.moond412@gmail.com>, vignesh C <vignesh21@gmail.com>, Shlok Kyal <shlok.kyal.oss@gmail.com>, "Hayato Kuroda (Fujitsu)" <kuroda.hayato@fujitsu.com>, shveta malik <shveta.malik@gmail.com>, Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>, Ajin Cherian <itsajin@gmail.com>, Bertrand Drouvot <bertranddrouvot.pg@gmail.com>, Masahiko Sawada <sawada.mshk@gmail.com>, Nathan Bossart <nathandbossart@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>, Peter Smith <smithpb2250@gmail.com>
Date: 2025-02-10T06:09:45Z
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 Sat, Feb 8, 2025 at 12:28 PM Zhijie Hou (Fujitsu)
<houzj.fnst@fujitsu.com> wrote:
>
> 3.
>
> +                       if (cause & RS_INVAL_HORIZON)
> +                       {
> +                               if (!SlotIsLogical(s))
> +                                       goto invalidation_marked;
>
> I am not sure if this logic is correct. Even if the slot would not be
> invalidated due to RS_INVAL_HORIZON, we should continue to check other causes.
>

Isn't this comment apply to even the next condition (if (dboid !=
InvalidOid && dboid != s->data.database))? We need to probably
continue to check other invalidation causes unless one is set.

> Besides, instead of using a goto, I personally prefer to move all these codes
> into a separate function which would return a single invalidation cause.
>

Instead of using goto label (invalidation_marked:), won't it be better
if we use a boolean invalidation_marked and convert all if's to if ..
else if .. else cases?

> 4.
> -       if (InvalidateObsoleteReplicationSlots(RS_INVAL_WAL_REMOVED,
> +       if (InvalidateObsoleteReplicationSlots(RS_INVAL_WAL_REMOVED | RS_INVAL_IDLE_TIMEOUT,
>                                                                                    _logSegNo, InvalidOid,
>                                                                                    InvalidTransactionId))
>
> I think this change could trigger an unnecessary WAL position re-calculation when
> slots are invalidated only due to RS_INVAL_IDLE_TIMEOUT.
>

Why is that unnecessary? If some slots got invalidated due to timeout,
we don't want to retain the WAL corresponding to them.


-- 
With Regards,
Amit Kapila.