MySQL :: MySQL 5.1 Reference Manual :: 15 MySQL Load Balancer
The MySQL Load Balancer is an application that communicates with one or more MySQL servers and provides connectivity to those servers for multiple clients. The MySQL Load Balancer is logically placed between the clients and the MySQL server; instead of clients connecting directly to each MySQL server, all clients connect to the MySQL Load Balancer, and the MySQL Load Balancer forwards the connection on to one of the MySQL servers.