Squid: The Definitive Guide Author: Duane Wessels Pages: 441 Publisher: O'Reilly ISBN: 0-596-00162-2 Summary: An excellent guide to running the squid caching proxy. Review Date: 28 February, 2004

O'Reilly is known for the quality of their technical books, and yet even among O'Reilly titles there are those that stand head and shoulders above their peers in terms of quality and usefulness. Volumes such as the bat and the camel, that come to be indispensible, and required reading for any serious user in their field. Squid: The Definitive Guide definitely deserves a place among these classics in the O'Reilly bestiary.

I think there are two main factors that make this book as good as it is. Number one is that author is one of the principal developers of squid, and his extensive knowledge of the internals of the software is readily apparent. That knowledge permeates the text, and sheds light where any author who was only a user of squid could never reach. As such the book is very authoritative. The other factor is that between Mr. Wessels and his editors, the book is strikingly clear, easy to read, and easy to follow. Between the two factors you have a book that certainly lives up to its title, a "definitive guide."

Being relatively new to Squid myself, the book certainly had its work cut out for it, to describe clearly the workings of a piece of software with a configuration file that sports hundreds of potentially confusing directives. With the book in hand, however, the various options are explained, best practices are provided, and a clear path to a well-tuned, working configuration is illuminated. Having read through the book, and with its help, I feel confident I could easily bring up a squid proxy configured and tuned to my needs without too much effort. Examples are plentiful throughout the book, and the author and editors demonstrate the much welcome capability to know just when a topic is complex enough to require multiple examples and additional explanation to ease the learning curve.

The book lays out how you go about obtaining squid, and how to install and initially configure it. It covers the various storage options for the disk cache. It gives very helpful descriptions of how to configure access controls, which without such a guide would be difficult at best to configure correctly. The book also describes various deployment scenarios, and how best to configure squid for each, including deploying squid in a caching heirarchy. Additionally the book covers how to make the most of squid's logging capabilities, and the various mechanisms available to monitor squid. Finally, the book provides tips on how to debug problems, should they arise.

Even among the O'Reilly elite, however, few books are born perfect. Appendix A in the book provides a squid config file reference, listing each of the numerous config file parameters along with a description of the parameter, its syntax, default value, and an example of its usage. Other related parameters are also provided for cross-reference. In terms of content, the material is excellent. In terms of order, however, I find it lacking. The entries are listed in the order they appear in the default squid.conf file. Why the author and editors chose that order over alphabetical order leaves me scratching my head. I see it as a detriment, as you would likely have to do an index lookup for a parameter of interest instead of just locating it alphabetically.

Warts and ordering aside, the content is great. The book is well-written, well edited, and authoritative. It serves well as both tutorial and reference. If you work with, or are planning to work with squid, you'll likely find Squid: The Definitive Guide a welcome companion in your endeavors.

Overall Rating: 9/10