Pgpool

Pgpool is a connection pooling/replication server for PostgreSQL.

pgpool-II architecture

pgpool-II features

• uses multiple DB nodes to process search queries in parallel for higher performance compared to a single PostgreSQL server
• comes with web-based administration tool called "pgpoolAdmin" for easier operation (figure on the right)
• up to 128 DB nodes can be attached (can be extended by recompilation)
• can be operated using a port opened in pgpool-II for administration via network

 For now, only pgpoolAdmin is released as a pgpool-II administration tool. Since C library and protocol format documentation is available, however, new administration tool can be created if needed. 

• http://pgfoundry.org/projects/pgpool/
• http://pgpool.projects.postgresql.org/