Apache: The Definitive Guide, 3rd Edition

Performance Tuning

A quick web site is well on the way to being a good web site. It is probably worth taking a little trouble to speed up your scripts; but bear in mind that most elapsed time on the Web is spent by clients looking at their browser screens, trying to work out what they’re about.

We discuss the larger problems of speeding up whole sites in Chapter 12. Here we offer a few tips on making scripts run faster in less space. The faster they run, the more clients you can serve in sequence; the less space they run in, the more copies you can run and the more clients you can serve simultaneously. However, if your site attracts so many people it is still bogging down, you can surely afford to throw more hardware at it. If you can’t, why are you bothering?

Users of FreeBSD might like to look at http://www.freebsd.org/cgi/man.cgi?query=tuning for some basic suggestions

The search for perfect optimization can get into subtle and time-consuming byways that are very dependent on the details of how your scripts work. A good reason not to spend too much time on optimizing your code is that the small change you make tomorrow to fix a maintenance problem will probably throw the hard-won optimizations all out of whack.