Re: Load balancing with slave/master and failover

[Daniel Wharton]

I don't believe any lua for this exists publicly ATM. To be honest, I find the notion very scary : )

You may want to start with rw-splitting.lua and work in the master fail-over. In my experience, its tough to get read-only servers to fail over gracefully. Either the built in functions for detecting the up-ness or down-ness of a server are faulty or the currently available logic in published lua scripts doesn't work well. Generally my proxies start to barf all over themselves if any of the DB servers become unavailable.

You may be better off doing IP address moving via something like CARP (openbsd) or heartbeat on linux. With heartbeat you can even have the system run some commands after failover to get mysql to start using the new IP address. You can configure safe failback or whatever it is so that the change is permanent until manual intervention.