Programmers love performance. We like to talk about it and form theories, but we don't know how to measure it. And when we do, we don't know what to do with the numbers we get. Benchmarking with httperf shows how to use the very simple (but capable) httperf command-line tool. It also explains the basic statistics you need to know to compare separate benchmarking runs. You'll also learn how to use httperf to find the maximum performance of a single Mongrel instance. You can use this same technique to tune your server and find the optimum number of Mongrel processes to use in your cluster.