At almost 900 pages, this is certainly the biggest book on mod_perl that has been published so far. In my opinion it's also one of the most useful. Stas Bekman and Eric Cholet are two of the best-known and (probably more importantly) most respected names in the mod_perl community so you can be sure the the information you get in this book is going to be top quality. Part 1 of the book is about mod_perl administration. It starts with an overview of what mod_perl is and how it relates to CGI and the Apache web server before going into a chapter which gives a quickstart guide to installing and using mod_perl on some of the most common platforms. Chapter three then goes back over the installation process in far more detail. Chapter four explains how to configure mod_perl in various ways and chapter five cover monitoring, upgrading and maintaining your mod_perl enabled web server. Chapter 6 is full of advice about how to write Perl code that takes advantage of mod_perl's features. Part 2 is all about mod_perl performance and contains chapters about benchmarking and tuning your server. I found chapter twelve to be particularly useful as it discusses a number of useful strategies for splitting server load between a mod_perl server for dynmaic content and a "plain" (non-mod_perl) server for static content. Other chapters in this section cover other strategies for improving performance by tuning Apache's configuration, changing your Apache and mod_perl build options and being cleverer about the HTTP headers that you return. Most dynamic web sites have a database involved somewhere so part 3 covers using databases with mod_perl. Part 4 is all about debugging and troubleshooting your mod_perl server. Finally, part 5 looks at what has changed with the release of the forthcoming mod_perl 2.0. And this isn't just theoretical stuff. The two authors have been involved in developing mod_perl for a long time but they are also mod_perl users. You can just tell from the way they write that the problems they discuss are problems they have dealt with. This is the voice (or, rather, voices) of experience. A lot of the text in the book is based on the mode_perl guide which has been available on the web for some time, but all of the content has been revisited, updated and expanded. This book is not really in competition with books like The mod_perl Developers Cookbook or the older Writing Apache Modules with Perl and C as those books largely concentrate on how to write code for mod_perl whereas the emphasis in this book is on configuring and administering a mod_perl server. And if you are the administrator of a mod_perl server then you should really consider adding this book to your library.
I bought this book to better understand mod_perl. I didn't expect such a thick tome to be the result - 924 pages. However, I've read every page. The book covers many areas of mod_perl with thoroughness I didn't expect. What also surprised me was the amount of experience & advice about general web-serving issues & setup options. I've certainly learned more about this area, and its helped clarify some of my thinking especially about performance & security. Some areas I was surprised were included, such as using DBM's, which (though interesting) seemed of minimal relevance to a mod_perl book. Same goes for discussions about Inline & XS. Also, you get the impression that the book was written as a number of separate essays, which results in some overlap and repitition - not necessarily a bad thing. It was also nice to see a good overview of Apache 2 and mod_perl 2. One thing I was looking forward to was a discussion on sharing memory & dynamic variables between Apache child processes, but unfortunately this was one of the few areas glossed over in the book. In short, this book could easily have been presented as 2 or 3 smaller ones, so a bargain to any mod_perl user out there, or indeed any apache web-server administrator who wants some experienced advice on configuration for users.