Re: Allow logical failover slots to wait on synchronous replication - Mailing list pgsql-hackers

On Mon, Sep 16, 2024 at 2:55 PM shveta malik <shveta.malik@gmail.com> wrote:
>
> On Mon, Sep 16, 2024 at 11:13 AM Amit Kapila <amit.kapila16@gmail.com> wrote:
> >
>
> > Another question aside from the above point, what if someone has
> > specified logical subscribers in synchronous_standby_names? In the
> > case of synchronized_standby_slots, we won't proceed with such slots.
> >
>
> Yes, it is a possibility. I have missed this point earlier. Now I
> tried a case where I give a mix of logical subscriber and physical
> standby in 'synchronous_standby_names' on pgHead, it even takes that
> 'mix' configuration and starts waiting accordingly.
>
> synchronous_standby_names = 'FIRST 2(logicalsub_1, phy_standby_1,
> phy_standby_2)';
>

This should not happen as we don't support syncing failover slots on
logical subscribers. The other point to consider here is that the user
may not have set 'sync_replication_slots' on all the physical standbys
mentioned in 'synchronous_standby_names' and in that case, it doesn't
make sense to wait for WAL to get flushed on those standbys. What do
you think?

--
With Regards,
Amit Kapila.