Re: Attempting to do a rolling move to 9.2Beta (as a slave) fails

Hi Karl,

On Sun, May 27, 2012 at 9:18 PM, Karl Denninger <karl(at)denninger(dot)net> wrote:

> Here's what I'm trying to do in testing 9.2Beta1.
>
> The current configuration is a master and a hot standby at a diverse
> location for both hot swap and "online" backup. Both are archived
> regularly so if something goes south I can recover (to either as a master.)
>

Okay

> 1. Build 9.2Beta1; all fine.
>
> 2. Run a pg_basebackup from the current master machine (running 9.1) to a
> new directory on the slave machine, using the 9.2Beta1 pg_basebackup
> executable.
>
> 3. Run a pg_upgrade against that from the new binary directory, producing
> a 9.2Beta1 data store.
>
> 4. Attempt to start the result as a SLAVE against the existing 9.1 master.
>

Hmm - that's likely a problem: "In general, log shipping between servers
running different major PostgreSQL release levels is not possible." [1]

> Is this caused by the version mismatch?
>

Probably.

> Do I need to run a complete parallel environment instead of trying to
> attach a 9.2Beta1 slave to an existing 9.1 master? (and if so, why doesn't
> the code complain about the mismatch instead of the bogus WAL message?)
>

Slony [2] or PGBouncer+Londiste [3] should allow you to do this in an
integrated fashion. [4]

Cheers,

Jan

[1] http://www.postgresql.org/docs/current/static/warm-standby.html
[2] http://slony.info/
[3] http://itand.me/zero-downtime-upgrades-of-postgresql-with-pgb
[4]
http://www.postgresql.org/docs/current/static/different-replication-solutions.html