Re: 9.5 beta pg_upgrade documentation

On Sun, Aug 23, 2015 at 09:45:50AM -0500, Andy Colson wrote:
> I think we should add a step 6.5 (before step 7 Stop both servers) with something like:
>
> If you are upgrading both a primary and standby, then we need to make sure the standby is caught up.
> If you are wal shipping then on primary run: select pg_switch_xlog();
> shut down primary
> before you shut down the standby make sure it gets caught up to the primary.
>
> I don't think its 100% required for them to be exact, is it? If they are a little different then rsync has more data to xfer from primary to standby ... but it would still work. Right?

You are one of the first to use this new ability so it is good to get
your feedback. I have developed the attached applied patch to address
the problems you saw.

First, the verification has to happen earlier, before pg_upgrade is run.
I think what is happening is that a checkpoint on server shutdown is
changing the value while pg_upgrade is running, and the rename of the
controldata file is another issue, so doing it right after the primary
is shut down is the right place.

I also added a mention that rsync, not pg_upgrade, will be run on the
standbys. You can see all the results of the patch here:

http://momjian.us/pgsql_docs/pgupgrade.html

Thanks.

--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com

+ Everyone has their own god. +