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: Amit Kapila <amit.kapila16@gmail.com>
Cc: Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>, Nathan Bossart <nathandbossart@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2024-03-18T09:32:40Z
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 Mon, Mar 18, 2024 at 08:50:56AM +0530, Amit Kapila wrote:
> On Sun, Mar 17, 2024 at 2:03 PM Bharath Rupireddy
> <bharath.rupireddyforpostgres@gmail.com> wrote:
> >
> > On Sat, Mar 16, 2024 at 3:55 PM Amit Kapila <amit.kapila16@gmail.com> wrote:
> > >
> > > procArray->replication_slot_catalog_xmin) but then don't adjust it for
> > > 'max_slot_xid_age'. I could be missing something in this but it is
> > > better to keep discussing this and try to move with another parameter
> > > 'inactive_replication_slot_timeout' which according to me can be kept
> > > at slot level instead of a GUC but OTOH we need to see the arguments
> > > on both side and then decide which makes more sense.
> >
> > Hm. Are you suggesting inactive_timeout to be a slot level parameter
> > similar to 'failover' property added recently by
> > c393308b69d229b664391ac583b9e07418d411b6 and
> > 73292404370c9900a96e2bebdc7144f7010339cf? With this approach, one can
> > set inactive_timeout while creating the slot either via
> > pg_create_physical_replication_slot() or
> > pg_create_logical_replication_slot() or CREATE_REPLICATION_SLOT or
> > ALTER_REPLICATION_SLOT command, and postgres tracks the
> > last_inactive_at for every slot based on which the slot gets
> > invalidated. If this understanding is right, I can go ahead and work
> > towards it.
> >
> 
> Yeah, I have something like that in mind. You can prepare the patch
> but it would be good if others involved in this thread can also share
> their opinion.

I think it makes sense to put the inactive_timeout granularity at the slot
level (as the activity could vary a lot say between one slot linked to a 
subcription and one linked to some plugins). As far max_slot_xid_age I've the
feeling that a new GUC is good enough.

> > Alternatively, we can go the route of making GUC a list of key-value
> > pairs of {slot_name, inactive_timeout}, but this kind of GUC for
> > setting slot level parameters is going to be the first of its kind, so
> > I'd prefer the above approach.
> >
> 
> I would prefer a slot-level parameter in this case rather than a GUC.

Yeah, same here.

Regards,

-- 
Bertrand Drouvot
PostgreSQL Contributors Team
RDS Open Source Databases
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