I am using this mysql slave status plugin and on the munin master I have added...
mysql_slave_status.warning 30 mysql_slave_status.critical 60
So it alerts whenever the slave gets behind the master. How do I get munin to alert me (critical alert if possible) when the plugin returns "NaN", will it do that automatically?
It returns NaN when the SQL isn't running or the connection fails.
EDIT: In the end I made it add a large number to the actual value if the connection was down.