There is a new version of the Nagios plugin check_mysql_slavestatus available, which is used to check MySQL slaves.
Dan Virlan reported that the plugin output always returns OK in his setup, even when he did some tests and stopped the master. After some debugging, this was happening, because the status of "Slave_IO_Running" was "Connecting" - the plugin however couldn't work with that status. Until now.
In case something similar would happen (a status which is unknown to the plugin), the plugin was adapted accordingly.
Besides that, the whole end of the plugin, mainly the threshold section, was completely rewritten and a public repo was created on github: https://github.com/Napsty/check_mysql_slavestatus.