Re: pg_upgrade and logical replication

On Thu, Nov 2, 2023 at 3:41 PM vignesh C <vignesh21(at)gmail(dot)com> wrote:
>
> I have slightly modified it now and also made it consistent with the
> replication slot upgrade, but I was not sure if we need to add
> anything more. Let me know if anything else needs to be added. I will
> add it.
>

I think it is important for users to know how they upgrade their
multi-node setup. Say a two-node setup where replication is working
both ways (aka each node has both publications and subscriptions),
similarly, how to upgrade, if there are multiple nodes involved?

One more thing I was thinking about this patch was that here unlike
the publication's slot information, we can't ensure with origin's
remote_lsn that all the WAL is received and applied before allowing
the upgrade. I can't think of any problem at the moment due to this
but still a point worth giving a thought.

--
With Regards,
Amit Kapila.