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

On Tue, Mar 26, 2024 at 2:27 PM Bharath Rupireddy
<bharath(dot)rupireddyforpostgres(at)gmail(dot)com> wrote:
>
> >
> > 1)
> > Commti msg:
> >
> > ensures the value is set to current timestamp during the
> > shutdown to help correctly interpret the time if the standby gets
> > promoted without a restart.
> >
> > shutdown --> shutdown of slot sync worker (as it was not clear if it
> > is instance shutdown or something else)
>
> Changed it to "shutdown of slot sync machinery" to be consistent with
> the comments.

Thanks for addressing the comments. Just to give more clarity here (so
that you take a informed decision), I am not sure if we actually shut
down slot-sync machinery. We only shot down slot sync worker.
Slot-sync machinery can still be used using
'pg_sync_replication_slots' SQL function. I can easily reproduce the
scenario where SQL function and reset_synced_slots_info() are going
in parallel where the latter hits 'Assert(s->active_pid == 0)' due to
the fact that parallel SQL sync function is active on that slot.

thanks
Shveta