MySQL Proxy is a simple and new program that sits between your client and MySQL server(s) that can monitor, analyze or transform their communication. Its flexibility allows for a wide variety of use cases, including:
a) Load balancing
c) Query analysis
d) Query filtering and modification
e) and many more...
MySQL Proxy tutorial
Oreilly has published a nice tutorial using MySQL proxy application:
MySQL Proxy is a lightweight binary application standing between one or more MySQL clients and a server. The clients connect to the Proxy with the usual credentials, instead of connecting to the server. The Proxy acts as man-in-the-middle between client and server.
In its basic form, the Proxy is just a redirector. It gets an empty bucket from the client (a query), takes it to the server, fills the bucket with data, and passes it back to the client.
If that were all, the Proxy would just be useless overhead. There is a little more I haven't told you yet. The Proxy ships with an embedded Lua interpreter. Using Lua, you can define what to do with a query or a result set before the Proxy passes them along.
Download MySQL proxy
You can download MySQL proxy here