While there are many graphing tools out there and we’ve used Munin for a while now.
The MySQL plugin for Munin had fallen out of date and the show engine innodb status output changed in 5.5 making some bits of the plugin simply not work any more. Also the show global status has some extra variables so there was a need to create new graphs.
All of these are now in the 2.1.8+ development releases of Munin.
Here are samples of the new/updated graphs.