Обсуждение: Warm standby (log shipping) from PG 8.3 to 9.3

Is it safe to assume that my working PG 8.3 archive command on the
master and recovery.conf (using contrib's pg_standby) on the standby
will work the same under 9.3?

That is, under PG 8.3, my master server uses:

archive_mode = on
archive_command = '~/postgresql/bin/copyWAL "%p" "%f"'
archive_timeout = 300

(and copyWAL does an SCP to the warm standby's recovery WALs directory)

And my warm standby recovery warm standby uses recovery.conf:

restore_command = '~/postgresql/bin/pg_standby -l -d -t
~/postgresql/recoveryWALs/STOP_RECOVERY ~/postgresql/recoveryWALs %f %p
%r 2>> ~/postgresql/logs/pg_standby.log'

I'm getting ready to do a migration to upgraded versions to 9.3 and
wanted to know if I had to address this concern or whether it should
just work the same as in 8.3.  We're not ready to try streaming.

I'll read up on what it means to do hot standby instead of warm
standby.  We don't expect to need to use the standby for running queries
from our app, but it would sure be nice, from a comfort level, for
operations to be able to see updates in the standby.  Is it really just
as easy as our current warm standby but just adding 'wal_level =
hot_standby' to the master's postgresql.conf ?  Is there anything I can
read about moving from 8.3 warm standby to 9.3 hot standby?

It's a bit confusing because of the various options for standby mode.
Would it be better to use the new standby setup instead of pg_standby?

Thanks,
David

On 6/10/2014 11:54 AM, hubert depesz lubaczewski wrote:

On Tue, Jun 10, 2014 at 8:13 PM, David Wall <d.wall@computer.org> wrote:

Is it safe to assume that my working PG 8.3 archive command on the master and recovery.conf (using contrib's pg_standby) on the standby will work the same under 9.3?

Yes, it will work just fine. Of course you can't load 9.3 xlogs into 8.3, or 8.3 xlogs into 9.3, but the commands are the same.

Thanks.  Yes, that makes sense as I'll update both DBs to the same version and we'll likely start with a fresh DB snapshot.

Do you know if there's a way to turn that warm standby into a hot standby (so I can query the standby during its ongoing recovery) easily?  Any docs that show the changes necessary to make that happen, or is that a bigger task?

David