Re: Upgrade master/slave: rsync?

On Wed, Sep 13, 2017 at 03:01:50PM -0500, Don Seiler wrote:
> Thinking more on this in my situation. The databases I've inherited have the
> default system tables in the default tablespaces under $PGDATA (/var/lib/pgsql/
> 9.2/data), but then also has most of the app-specific data on separate
> tablespaces outside of the data directory (eg various directories under /opt/
> postgres). Of course this also means the various symlinks to these from $PGDATA
> /pg_tblspc. For these, pg_upgrade will create a new directory
> (PG_9.6_201608131) with hard-links (assuming I used the --link option) to the
> old PG_9.2_201204301 directory, and then add symlinks from the new 9.6 $PGDATA
> directory to the tablespace location.
>
> I'm just trying to walk through this in my head. I'd need to run a similar
> rsync command for each of these. For example, for tablespace foo with location
> /opt/postgres/foo:
>
> cd /opt/postgres/foo
> rsync --archive --delete --hard-links --size-only PG_9.2_201204301
> PG_9.6_201608131 standby.host.com:/opt/postgres/foo

Yes.

> And then rinse & repeat for any others similar tablespaces for each standby/
> slave?
>
> Another question. I have one slave in the same datacenter as the master, the
> other slaves are in the DR data center across the country. I'm assuming I could
> sync those DR slaves from the local slave? That way I can get the master back
> online and serving requests as soon as the local slave is successfully upgraded
> rather than waiting for rsync over the WAN? And then one DR slave could be
> copied from the other so I only have to do the WAN rsync once (especially if
> it's a downstream standby in a cascading scenario)?

Yes.

I think you will find answers to these questions in the updated
pg_upgrade docs that were backpatched to 9.5:

https://www.postgresql.org/docs/9.6/static/pgupgrade.html

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

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