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

On Wed, Sep 18, 2024 at 12:21 PM shveta malik <shveta(dot)malik(at)gmail(dot)com> wrote:
>
> On Mon, Sep 16, 2024 at 3:31 PM Bharath Rupireddy
> <bharath(dot)rupireddyforpostgres(at)gmail(dot)com> wrote:
> >
> > Hi,
> >
> >
> > Please find the attached v46 patch having changes for the above review
> > comments and your test review comments and Shveta's review comments.
> >
>
> Thanks for addressing comments.
>
> Is there a reason that we don't support this invalidation on hot
> standby for non-synced slots? Shouldn't we support this time-based
> invalidation there too just like other invalidations?
>

Now since we are not changing inactive_since once it is invalidated,
we are not even initializing it during restart; and thus later when
someone tries to use slot, it leads to assert in
ReplicationSlotAcquire() ( Assert(s->inactive_since > 0);

Steps:
--Disable logical subscriber and let the slot on publisher gets
invalidated due to inactive_timeout.
--Enable the logical subscriber again.
--Restart publisher.

a) We should initialize inactive_since when
ReplicationSlotSetInactiveSince() is called from RestoreSlotFromDisk()
even though it is invalidated.
b) And shall we mention in the doc of 'active_since', that once the
slot is invalidated, this value will remain unchanged until we
shutdown the server. On server restart, it is initialized to start
time. Thought?

thanks
Shveta