While Nagios is well established in the system administration community, it retains a few shortcomings due to its long legacy. This is not to suggest that Nagios is a bad platform! However, we can make it better for our own uses and for other administrators that help us monitor our database clusters.

check_mk is a popular extension to Nagios that provides a better interface, more built-in monitors, and—for those interested—a GUI management system. This management GUI is actually one of the main things we will cover in this recipe, as it has some idiosyncrasies of its own. However, once we're done presenting the basics, we encourage you to experiment with some of its more powerful features.