Horton

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

Nisha Moond <nisha.moond412@gmail.com>

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From: Nisha Moond <nisha.moond412@gmail.com>
To: Amit Kapila <amit.kapila16@gmail.com>
Cc: Peter Smith <smithpb2250@gmail.com>, Shlok Kyal <shlok.kyal.oss@gmail.com>, vignesh C <vignesh21@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>
Date: 2025-01-28T11:56:51Z
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, Jan 27, 2025 at 4:20 PM Amit Kapila <amit.kapila16@gmail.com> wrote:
>
> On Mon, Jan 27, 2025 at 11:00 AM Nisha Moond <nisha.moond412@gmail.com> wrote:
> >
> > I discussed the above comments further with Peter off-list, and here
> > are the v63 patches with the following changes:
> >  patch-001: The Assert and related comments have been updated for clarity.
> >
>
> The 0001 patch should be discussed in a separate thread as those are
> general improvements that are useful even without the main patch we
> are trying to achieve in this thread. I suggest we break it into three
> patches (a) Ensure the same inactive_since time for all slots, (b)
> Raise an error for invalid slots during ReplicationSlotAcquire(); tell
> in the commit message, without this patch when such an ERROR would
> have otherwise occurred, and (c) Changes in
> InvalidatePossiblyObsoleteSlot(), I suggest to leave this change for
> later as this impacts the core logic of invalidation.
>

I have started a new thread for these general improvements and have
separated the changes (a) and (b) into different patches.

You can find the new thread at [1].

> *
> @@ -812,7 +823,7 @@ ReplicationSlotAlter(const char *name, const bool *failover,
>   Assert(MyReplicationSlot == NULL);
>   Assert(failover || two_phase);
>
> - ReplicationSlotAcquire(name, false);
> + ReplicationSlotAcquire(name, false, false);
>
> Why don't we want to give ERROR during Alter? I think it is okay to
> not give ERROR for invalid slots during Drop as we are anyway removing
> such slots.
>

Because ReplicationSlotAlter() already handles errors immediately
after acquiring the slot. It raises errors for invalidated slots and
also raises a different error message if the slot is a physical one.
So, In case of ALTER, I feel it is okay to acquire the slot first
without raising errors and then handle errors in the pre-defined way.
Similar immediate error handling is not available at other places.

[1] https://www.postgresql.org/message-id/CABdArM6pBL5hPnSQ%2B5nEVMANcF4FCH7LQmgskXyiLY75TMnKpw%40mail.gmail.com

--
Thanks,
Nisha