Re: Automatic Client Failover

On Mon, Aug 04, 2008 at 05:17:59PM -0400, Jonah H. Harris wrote:
> On Mon, Aug 4, 2008 at 5:08 PM, Simon Riggs <simon(at)2ndquadrant(dot)com> wrote:
> > When primary server fails, it would be good if the clients connected to
> > the primary knew to reconnect to the standby servers automatically.
>
> This would be a nice feature which many people I've talked to have
> asked for. In Oracle-land, it's called Transparent Application
> Failover (TAF) and it gives you a lot of options, including the
> ability to write your own callbacks when a failover is detected.

This might be better done as part of a proxy server, eg pgbouncer, pgpool
than as part of postgresql or libpq. I like the concept, but the logic to
determine when a failover has occurred is complex and a client will often
not have access to enough information to make this determination accurately.

postgresql could have hooks to support this though, ie to determine when a
standby thinks it has become the master.

-dg

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David Gould daveg(at)sonic(dot)net 510 536 1443 510 282 0869
If simplicity worked, the world would be overrun with insects.