Re: Multi-Master-Solution (PGCluster)?

On Thu, 2005-12-08 at 04:16, Jens Carl wrote:
> Hello list,
>
> we need urgently a database cluster with load balancing, high available
> and multi-master support. We would like use as database engine PostgresSQL.
> The only propgramm we found is pgcluster. But it seems to be in beta
> stage und has no support for pgSQl 8.1.
>
> Has anybody experience with PGCluster or has somebody another tip for me?

If a synchronous two machine system would work, you might want to look
into pgpool, which is kind of a country cousin to pgcluster, in that a
fair bit of its code is in pgcluster.

pgpool can handle two machines running synchronously and do failover
automagically. Of course, you've got the standard caveats that things
like random() in an update are a bad idea, and timestamps might not
exactly match, since it is a query shipping solution, not log shipping.

OTOH, a lot of folks use a shared storage array with takeover to ensure
uptime. Those are nice because you don't have to worry about two copies
getting out of sync, since there's really only one copy. A pair of a
pair of machines with one set as the master and one as the slave in a
slony replication farm could give you very high uptimes.