Query Load Balancing in Pgpool-II
Pgpool-II is a PostgreSQL cluster management tool. The major features of Pgpool-II are: Connection pooling Query load balancing Automated failover Watchdog (High availability of Pgpool-II) Replication In memory query cache In this post, I will describe the query load balancing mechanism in Pgpool-II and the relevant configuration parameters. Why use query load balancing? Query load balancing can distribute database server workloads across multiple PostgreSQL servers. Nowadays, most database systems use multiple replicated database servers to achieve high availability for PostgreSQL. Pgpool-II takes the advantage of the replication feature in order to distribute the workloads across multiple PostgreSQL servers. If there is a PostgreSQL cluster with multiple PostgreSQL servers, Pgpool-II is able to distribute READ queries across those PostgreSQL servers. The benefit of READ queries load balancing is, improve the system's throughput reduce the load on each PostgreSQL server optimize...