Monitoring CPU performance with Rails and Mongrel on Ruby

Producing, pamintaining and reviewing system logs and graphs for predicting future requirements is a primary sysadmin responsibility. Ruby and Rails can both be used to make your job easier, and more professional.

Monitoring Rails Performance with Munin and a Mongrel

Once your application is moved into production, it becomes important to keep an eye on performance over time in order to get a feel for trends and plan capacity intelligently. Numerous Rails performance measuring tools exist, but I find that it helps to correlate performance of your application with simultaneous lower-level performance metrics of your system (CPU and Memory usage, Load Average, etc). Besides that, hey! Pretty Graphs! Enter munin, an open-source, extensible monitoring tool with a number of out-of-the-box plugins that are useful to SysAdmin type folks. There’s a pretty decent (though brief) writeup on howtoforge that explains a bit more about how to go about getting your own munin. Go ahead and check it out—I’ll chill here until you’re back.