Re: Synchronizing slots from primary to standby

On Thu, Mar 7, 2024 at 12:00 PM Zhijie Hou (Fujitsu)
<houzj.fnst@fujitsu.com> wrote:
>
>
> Attach the V108 patch set which addressed above and Peter's comments.
> I also removed the check for "*" in guc check hook.
>


Pushed with minor modifications. I'll keep an eye on BF.

BTW, one thing that we should try to evaluate a bit more is the
traversal of slots in StandbySlotsHaveCaughtup() where we verify if
all the slots mentioned in standby_slot_names have received the
required WAL. Even if the standby_slot_names list is short the total
number of slots can be much larger which can lead to an increase in
CPU usage during traversal. There is an optimization that allows to
cache ss_oldest_flush_lsn and ensures that we don't need to traverse
the slots each time so it may not hit frequently but still there is a
chance. I see it is possible to further optimize this area by caching
the position of each slot mentioned in standby_slot_names in
replication_slots array but not sure whether it is worth.

--
With Regards,
Amit Kapila.