Chapter 3. Performance

You may be impressed with ModSecurity and all the interesting things we have used it for so far, but if you're like me you might have that nagging thought in the back of your head saying "Sure, it's powerful... but how much of a performance hit will my web service take if I implement this"? This chapter looks at exactly that—should you be worried about ModSecurity negatively impacting the responsiveness of your site or is the worry unfounded?

We will be looking at the way a typical web server responds when put under an increasing amount of load from client requests, both when it has ModSecurity disabled and when it is enabled, and will then be able to compare the results. After this we will look at the ways in which you can increase the performance of your server by tweaking your configuration and writing more efficient rules.