Re: Automatic Client Failover

On Fri, 2008-08-15 at 12:24 -0400, Bruce Momjian wrote:
> Simon Riggs wrote:
> > When primary server fails, it would be good if the clients connected to
> > the primary knew to reconnect to the standby servers automatically.
> >
> > We might want to specify that centrally and then send the redirection
> > address to the client when it connects. Sounds like lots of work though.
> >
> > Seems fairly straightforward to specify a standby connection service at
> > client level: .pgreconnect, or pgreconnect.conf
> > No config, then option not used.
> >
> > Would work with various forms of replication.
> >
> > Implementation would be to make PQreset() try secondary connection if
> > the primary one fails to reset. Of course you can program this manually,
> > but the feature is that you wouldn't need to, nor would you need to
> > request changes to 27 different interfaces either.
>
> I assumed share/pg_service.conf would help in this regard; place the
> file on a central server and modify that so everyone connects to another
> server. Perhaps we could even add round-robin functionality to that.

I do want to keep it as simple as possible, but we do need a way that
will work without reconfiguration at the time of danger. It needs to be
preconfigured and tested, then change controlled so we all know it
works.

--
Simon Riggs www.2ndQuadrant.com
PostgreSQL Training, Services and Support