Re: PostgreSQL clustering (shared disk)

On 8/16/07, Douglas McNaught <doug(at)mcnaught(dot)org> wrote:
>
> Devrim GÜNDÜZ <devrim(at)CommandPrompt(dot)com> writes:
>
> >> What I'm pondering here is that is the cluster able to keep the
> >> postmasters synchronized at all times so that the database won't get
> >> corrupted.
> >
> > Keep all the $PGDATA in the shared disk. That would minimize data loss
> > (Of course, there is still a risk of data loss -- the postmasters are
> > not aware of each other and they don't share each other's buffers, etc.)
>
> It would be much better to have the cluster software only run one
> postmaster at a time, starting up the secondary if the primary fails.
> That's the usual practice with shared storage.

This was my original intention. I'm still quite hesitant to trust the
fencing devices ability to quarantee that only one postmaster at a time is
running, because of the disastrous possibility of corrupting the whole
database.

Maybe I'm just better off using the more simple (crude?) method of drbd +
heartbeat?

Regards

MP