Re: pg_upgrade instructions involving "rsync --size-only" might lead to standby corruption?

On Thu, Sep 7, 2023 at 01:52:45PM -0400, Bruce Momjian wrote:
> On Mon, Jul 10, 2023 at 02:37:24PM -0700, Nikolay Samokhvalov wrote:
> > Maybe. It will require changes in other parts of this doc.
> > Thinking (here: https://gitlab.com/postgres/postgres/-/merge_requests/18/diffs)
> >
> > Meanwhile, attached is v2
> >
> > thanks for the comments
>
> I looked over this issue thoroughly and I think I see the cause of the
> confusion. In step 8 we say:
>
> 8. Stop both servers
> Streaming replication and log-shipping standby servers can remain
> ---
> running until a later step.
>
> Of course this has to be "must" and it would be good to explain why,
> which I have done in the attached patch.
>
> Secondly, in step 9 we say "verify the LSNs", but have a parenthetical
> sentence that explains why they might not match:
>
> (There will be a mismatch if old standby servers were shut down before
> the old primary or if the old standby servers are still running.)
>
> People might take that to mean that it is okay if this is the reason
> they don't match, which is incorrect. Better to tell them to keep the
> streaming replication and log-shipping servers running so we don't need
> that sentence.
>
> The instructions are already long so I am hesitant to add more text
> without a clear purpose.

Patch applied back to PG 11.

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Bruce Momjian <bruce(at)momjian(dot)us> https://momjian.us
EDB https://enterprisedb.com

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