Book Review: Apache Pocket Reference

"HTTP Pocket Reference" by Clinton Wong and "Apache Pocket Reference" by Andrew Ford are two new additions to the O'Reilly Pocket Reference series with sixteen other titles to its name.

For those who are unfamiliar with this series, they are small handy quick reference books measuring 4.25 by 7 inches. These two books have only one body; divided into main sections and not chapters. The sections are not numbered and continue on the same page where the previous section ends, giving the illusion that both books contain only one long chapter.

On its back cover, O'Reilly markets the "Apache Pocket Reference" as a companion volume to "Writing Apache Modules with Perl and C" and "Apache: The Definitive Guide, 2nd Edition". With only 111 pages and 18 main sections, the content kick off with a clear explanation of the typographical conventions used, followed by a brief outline of the command-line options for starting and stopping Apache. Then it lists all the directories, support utilities and modules that are included in the Apache web server distribution together with short descriptions. The modules are also listed with their assigned status, such as OPTIONAL, EXPERIMENTAL or BASE (compiled into the server by default). Next we have the directives with the usual information: directive syntax, contexts in which it may be used, the module that implements it, version compatibility, default value and a summary of its function followed by a list of environment variables.

The directives are presented in the sequence of those used in general configuration, in each phase of the Apache processes by order of occurrence, and in secure Apache implementations with explanations provided for each section. As they are not grouped by modules or sorted in alphabetical order, core Apache directives are scattered under different sections; but an index of directives has been thoughtfully included to facilitate searching for directives.

The secure Apache section aspires to cover all SSL directives implemented by mod_ssl, Apache-SSL, and commercial versions of secure Apache such as Red Hat Secure Web Server, Covalent Raven SSL Module, C2Net's Stronghold, and IBM HTTP Server. As the different versions often have different names for similar directives, it tries to clarify this confusing situation by providing a compatibility note indicating which implementations the SSL directives are applicable to. This is a very useful feature but we did find slightly out-of-date information.

Not all directives are included, and some experimental modules and optional modules have been omitted. Minor niggles include details on mod_status which is compiled into Apache by default is given the status OPTIONAL instead of BASE, and the closing ">" for container directives is missing in the top line of each direction subsection which gives the name of the directive so "<Directory>" is printed as "<Directory" but this can be overlooked as it is found in the syntax that follows.

Surprisingly Apache Pocket Reference is not a dry book as the occasional explanations under the various sections break the monotony of reading pages and pages of directives. Someone who is new to the Apache web server could still read the whole book at one go and discover the power of this web server without having to read a thick book.

We think this short and compendious book is most suitable for solution providers and professional services personnel who are working with Apache web server and constantly on the move, as it is packed with technical information, highly portable, fits snugly in a back pocket or jacket pocket and can be whipped out in a second when one Apache directive keeps eluding the mind. It is truly the constant companion for die-hard Apache users and like it or not, the copy you own will soon have dog-eared pages.

Moving on to our next book, "HTTP Pocket Reference" is aimed at providing a better understanding of HTTP for busy people such as system administrators, web site designers and developers, not to mention software engineers who need to grasp the gist of this subject without spending too much time poring over it. For the World Wide Web junkies who have not the slightest idea of how it all works, this will be an interesting revelation as it takes the mystery out of the communications between web servers and clients in a simple and easy-to-understand presentation.

For such a thin book, it manages to cram technical facts, dumps of HTTP transactions, many diagrams and tables within only 80 pages. First, it explains what HTTP is all about, the many advantages of understanding how HTTP works and then proceeds to dissect and analyse every component of a common web transaction between the client and server program which is made up of a request and a response message.

It then lists out and explains the various client request methods, server response codes, HTTP headers, URL encoding, the way client and server identify themselves, the use of Referer(sic) header, the way a client retrieves data from the server's response, Internet MIME Types and four bonus topics that are cookies, authorization, persistent connections, and client caching.

Some readers may prefer to have an index as there is none but this book is so very thin and concise that the time one spent looking through the index would be much better spent flipping through the pages, scanning for the information one required. As this is not a guide for implementing HTTP, detailed examples of applying the information are not provided.

This book is the perfect starting point for the curious and uninitiated Web surfers who want to deepen their knowledge of how it all works. For the technical professional, this will serve as the quick reference guide to server response codes, HTTP headers, character encoding, and Internet MIME types.

These two books are such a joy to review until we are now anxiously awaiting the imminent arrival of another member - mod_perl Pocket Reference and are looking forward to reviewing it.

If you are reading this review before August 15th 2000 we have a special competition where you can win one of four sets of these books. See Apache Week issue 210.