Re: Replication/Failover/HA solution

On Wed, Jul 30, 2003 at 01:10:06PM +0200, Dani Oderbolz wrote:
> >One possibility is to run postgresql (regular postgresql - no patches
> >required) controlled by heartbeat (http://www.linux-ha.org/) on two
> >nodes. Heartbeat will then make sure that only one of the nodes are
> >active at any time.
> >
> >You will have to put the databases on shared storage; either something
> >like a shared SCSI RAID, or a software replication device like drdb or
> >md+nbd.
>
> Another possibility (which I have not yet tested, but it was mentioned
> in many Magazine Articles
> (Linux Magazine, the German iX) is DRBD.
> This Tool creates a RAID which is Shared betwenn 2 Nodes.
> One Node is the Master and the Other is the Slave (and failover Node).
> The Master writes data locally and sends the data over to the slave.
> There are 3 Modes of Operation, A with highest Troughput but least
> trust, B with Medium Troughput,
> but Acceptable trust, and C with lowest (but still ok) troughput and
> highest trust.
>
> Just check it out here:
>
> http://www.complang.tuwien.ac.at/reisner/drbd/

If you read my post carefully you will actually see it's the _same_
possibility :)

But DRDB is only part of the solution - you also need something like
heartbeat to manage what node postgresql runs on.

--
Ragnar Kjorstad