I have written a tutorial to pgpool-II using PostgreSQL 9.0's streaming replication. The tutorial is designed to use minimum resource: a Linux box. On the box, pgpool-II, pgpoolAdmin(a PHP based pgpool-II GUI admin tool) and two PostgreSQL 9.0 instances.
Though the tutorial system is surprisingly simple, you could learn:
- How pgpool-II detects PostgreSQL failure and automatically promote a standby server to primary server
- How pgpool-II re-sync the failed node by using "online recovery" capability