Horton

Re: pg_upgrade and logical replication

Amit Kapila <amit.kapila16@gmail.com>

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From: Amit Kapila <amit.kapila16@gmail.com>
To: vignesh C <vignesh21@gmail.com>
Cc: Michael Paquier <michael@paquier.xyz>, "Hayato Kuroda (Fujitsu)" <kuroda.hayato@fujitsu.com>, Julien Rouhaud <rjuju123@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2023-11-02T11:30:55Z
Lists: pgsql-hackers 
On Thu, Nov 2, 2023 at 3:41 PM vignesh C <vignesh21@gmail.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.

Commits

  1. pg_upgrade: Retrieve subscription count more efficiently.

  2. Fix random failure in 004_subscription.

  3. Fix 004_subscription.pl to allow its usage in --link mode.

  4. Allow upgrades to preserve the full subscription's state.

  5. Prevent startup of logical replication launcher during pg_upgrade