The reason I’m looking at clustering is that the DB server will be handling a large number of users and any downtime is catastrophic. So reliability comes before any performance or administrative concerns in a clustering solution.

My platform is PostgreSQL 8.3 and SLES Linux.

I looked at 4 Solutions:
Option 1: Shared Disk (Heartbeat) Cluster (Heartbeat: SLES)
Option 2: Filesystem Replication Based (DR:BD / GNDB)
Option 3: DB Replication Based (Slony I)
Option 4: DB Replication Based (PGCluster)

I weighed the pro’s and con’s of each of them and eventually chose Option 1 as the best for my needs.

I like the heartbeat solution because:

• It’s simple
• There’s no data loss in a shared disk cluster
• There’s no replication overhead so no performance impact

Unfortunately, there is very little public documentation regarding heartbeat clusters used with PostgreSQL. I hope to rectify that over the next weeks and months, so stay tuned.