Re: [GENERA]: Postgresql-9.1.1 synchronous replication issue

On Thu, Feb 16, 2012 at 8:14 PM, Adrian Klaver <adrian(dot)klaver(at)gmail(dot)com>wrote:

> On Wednesday, February 15, 2012 10:21:02 pm Venkat Balaji wrote:
> > Andrian,
> >
> > Thanks a lot !
> >
> > So in this case you are not waiting for confirmation of the commit being
> >
> > > flushed
> > > to disk on the standby. It that case you are bypassing the primary
> > > reason for
> > > sync replication. The plus is transactions on the master will complete
> > > faster
> > > and do so in the absence of the standby. The minus is that you are in
> > > sort of an
> > > in between state.
> >
> > I understand. My worry and requirement is to ensure master is not
> disturbed
> > for any reason.
> > In sync rep, the biggest worry is if standby server is unavailable and is
> > down for longer time, master hangs and will be in the same state until
> > standby comes back up or replication must be broken temporarily (until
> > standby comes back up) so that master runs without interruption. This is
> a
> > costly exercise on production from downtime perspective.
>
> So just use regular streaming replication without sync rep. You get record
> based
> transaction shipping without having to wait for the standby. You will
> need to
> make sure that wal_keep_segments is big enough to cover any down time on
> the
> standby(you would need that for sync rep also).
>
>
As we already have streaming replication configured. We have rolled back
the plan of setting up synchronous replication.

Thanks,
VB