This section explains the details of tuning mod_perl and the scripts
running under it, so you can squeeze every ounce of power from your
server. Performance tuning is a very complex task requiring a lot of
understanding and experience, but once you acquire this knowledge you
can make magic with your server.
This part of the book would have been much shorter if we had limited
ourselves to telling only the facts, without any investigation
details. We decided to do the opposite. We show you different areas
that we think might be good to investigate in order to improve
performance; we show the code under test, the way it was executed,
and the results of the test, and we analyze these results and provide
conclusions. Each case demonstrates some aspect of the
performance-improvement process, so when you complete this part of
the book, you will be able to conduct similar tests and decide
what's the best on your own.
This section contains the following chapters:
Chapter 7 helps you track down exactly where your
performance problems are.
Chapter 8 gives you some guidelines on how to
determine that you're using the right hardware and
operating system. There's no point spending your
time tweaking the configuration of mod_perl if the problem actually
lies in the platform you're running on.
Chapter 9 introduces you to existing tools to
analyze your performance and talks about developing your own tools.
Chapter 10 explains how shared memory and forking
affect the performance of mod_perl and what you can do about it.
Chapter 11 covers the
httpd.conf file and how it can be modified to
improve the performance of mod_perl-enabled Apache.
Chapter 12 discusses techniques for setting up
your mod_perl-enabled Apache server in conjunction with other modules
and other services.
Chapter 13 discusses the trade-offs involved in
various coding techniques.
Chapter 14 is about how to keep memory usage from
spiraling out of control.
Chapter 15 talks about decisions you make when
building Apache and mod_perl from source that can affect performance.
Chapter 16 gives some guidance on how HTTP headers
can be used to speed up web transactions.
