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

On Sun, Mar 17, 2024 at 2:03 PM Bharath Rupireddy
<bharath(dot)rupireddyforpostgres(at)gmail(dot)com> wrote:
>
> On Sat, Mar 16, 2024 at 3:55 PM Amit Kapila <amit(dot)kapila16(at)gmail(dot)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.

> 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.

--
With Regards,
Amit Kapila.