Horton

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

Bertrand Drouvot <bertranddrouvot.pg@gmail.com>

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From: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
To: Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>
Cc: shveta malik <shveta.malik@gmail.com>, Amit Kapila <amit.kapila16@gmail.com>, Nathan Bossart <nathandbossart@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2024-04-01T09:59:51Z
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

Hi,

On Sun, Mar 31, 2024 at 10:25:46AM +0530, Bharath Rupireddy wrote:
> On Thu, Mar 28, 2024 at 3:13 PM Bertrand Drouvot
> <bertranddrouvot.pg@gmail.com> wrote:
> > I think in this case it should always reflect the value from the primary (so
> > that one can understand why it is invalidated).
> 
> I'll come back to this as soon as we all agree on inactive_since
> behavior for synced slots.

Makes sense. Also if the majority of us thinks it's not needed for inactive_since
to be an exact copy of the primary, then let's go that way.

> > I think when it is invalidated it should always reflect the value from the
> > primary (so that one can understand why it is invalidated).
> 
> I'll come back to this as soon as we all agree on inactive_since
> behavior for synced slots.

Yeah.

> > T4 ===
> >
> > Also, it looks like querying pg_replication_slots() does not trigger an
> > invalidation: I think it should if the slot is not invalidated yet (and matches
> > the invalidation criteria).
> 
> There's a different opinion on this, check comment #3 from
> https://www.postgresql.org/message-id/CAA4eK1LLj%2BeaMN-K8oeOjfG%2BUuzTY%3DL5PXbcMJURZbFm%2B_aJSA%40mail.gmail.com.

Oh right, I can see Amit's point too. Let's put pg_replication_slots() out of
the game then.

> > CR6 ===
> >
> > +static bool
> > +InvalidateSlotForInactiveTimeout(ReplicationSlot *slot, bool need_locks)
> > +{
> >
> > InvalidatePossiblyInactiveSlot() maybe?
> 
> I think we will lose the essence i.e. timeout from the suggested
> function name, otherwise just the inactive doesn't give a clearer
> meaning. I kept it that way unless anyone suggests otherwise.

Right. OTOH I think that "Possibly" adds some nuance (like InvalidatePossiblyObsoleteSlot()
is already doing).

> Please see the attached v30 patch. 0002 is where all of the above
> review comments have been addressed.

Thanks! FYI, I did not look at the content yet, just replied to the above
comments.

Regards,

-- 
Bertrand Drouvot
PostgreSQL Contributors Team
RDS Open Source Databases
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