http://www.maatkit.org/doc/mk-heartbeat.html
Simple script to monitor mysql replication delay. It updates a value on the master every second and checks how far behind the value is on the slave. Simple yet effective.
http://www.elevatedcode.com/articles/2007/12/05/replication-monitoring-with-monit/
Clever approach to monitoring mysql replication with monit. Ruby script checks replication is running and then touches a file, monit in turn monitors that file's timestamp and if it gets out of date, sends an alert. Sort of like a dead man switch. Clever.
