HTTP: The Definitive Guide

Michael Palmer writes "OK, how well you know HTTP? Here's a pop quiz: QUESTION: Did you know that the Keep-Alive header was valid in HTTP 1.0, but has been deprecated in HTTP 1.1? A) What does "deprecated" mean? B) What is the "Keep-Alive header?" C) That's too bad - I kind of thought Keep-Alive was handy! D) Get with the program... HTTP 1.1 came out in 1999. The Internet boom is over already! Persistent connections are the default in HTTP 1.1 anyway." Answer (not necessarily your answer) and the rest of Palmer's review follows. HTTP: The Definitive Guide author David Gourley, Brian Totty pages 656 pages publisher O'Reilly & Associates; 1st edition (September 2002) rating excellent overview, plus detail in core areas reviewer Michael Palmer ISBN 1565925092 summary An overview of HTTP and related topics

OK, so I answered "C". I am going to make bold the claim that HTTP: The Definitive Guide, the long-awaited O'Reilly book on HTTP is ambitious enough in breadth and depth that if you answered "B," "C," or "D," you will find this book useful and informative. This is primarily due to clear organization of the book, as well as its friendly (even chummy) writing style.

Even if you are a technically-inclined sort from the Marketing department, and answered "A," you could get a good technical overview of the plumbing of the Web by skimming through this book; plus, having any O'Reilly book on the shelf in your cubicle would score you some street cred with the guys sitting over in Development -- this could be the one you've actually read. :-)

Breadth Unless you answered "D," HTTP is more complicated than you think. This is especially true if, as the authors of a good technical book should do (and these authors do), one spends some time touching on matters one level down (to TCP/IP, and other areas, in this case), and one level up (to HTML, generally, in this case). Because the authors are particularly concerned with HTTP performance, details of the interactions between HTTP and adjacent levels can be important.

The book is divided into five main sections: 1) an overview of HTTP, URLs, and connection management; 2) HTTP Architecture, including Web servers, proxies, caches, gateways, tunnels, robots; 3) Identification, Authorization, and Security; 4) Entities, Encodings, and Internationalization; 5) Content Publishing and Distribution, including hosting, publishing, load balancing, logging. So, even if you classify yourself as a "D," or even if you are hacking on an extensible open-source router software platform (in that case, you are an "F"), you will find yourself pulling this book from the shelf from time to time to check on something in one of these areas. The modular organization of the book is good.

The full Table of Contents is available on line.

Depth One (unfortunate?) thing about the Web is that its "architecture" (if you can even call it that) evolved and grew piece by piece. The design goals people had in mind back in 1993, or even in 1999, have been blown away by what has happened on the ground. Inter-company politics have also been a big factor -- never helpful for promoting standardization, or sound design. (Perhaps another problem has been the lack of an O'Reilly book on HTTP to tie everything together!) Hence, not only do you have a confusing mass of obsolete and/or overlapping specifications documents, you also have major differences between how different browsers, servers, and proxies adhere to these specifications in practice. This is one place the book shines: sprinkled throughout the pages are little tidbits about compatibility or performance pitfalls, gleaned from much practical experience. (The authors were some of the architects of Inktomi's Traffic Server "enterprise class" Web cache. Think "proxy caching for all of AOL's Web traffic.") As one example: "Technically, any Connection header fields (including Connection: Keep-Alive) received from an HTTP/1.0 device should be ignored, because they may have been forwarded mistakenly by an older proxy server. In practice, some clients and servers bend this rule, although they run the risk of hanging on older proxies." I can just imagine the series of bug reports leading to the inclusion of that piece of advice in the book. There are many other such warnings and bits of advice, generally aimed at HTTP application developers, often with an eye to performance tuning.

Here again, appropriate depth of discussion for a variety of readers is handled by clear organization of the book. The basic background material is laid out, and as the authors dive deeper into detail they may make a suggestion like, "If you are [not] writing high-performance HTTP software... feel free to skip ahead." Then, at the end of every chapter, there is a section labelled, "For More Information," which is a collection of relevant references and links, for those who want to dig into the source documents themselves.

Cautions This book review is addressed to the Slashdot crowd, a very technically savvy audience, so it's appropriate to mention what this book is not. It's not a detailed technical reference on all the topics mentioned in the table of contents (above); it would be tough to fit all that material into the book's 650-plus pages. However, the book is a good overview of HTTP and many related topics. The book does dip down into the grungy detail in many areas, but this won't be your only reference if you are a Web application developer.

Conclusion Overall, this is one of the more accessible O'Reilly books I own. In addition, while experts will certainly seek out greater depth in their particular area of expertise, few people are expert in the whole range of topics related to HTTP that this book covers. In addition, the book provides many tips drawn from practical experience, and references to more detailed material. HTTP, if not the heart and soul of the Web (perhaps that is Web content itself), could perhaps be called the Web's circulatory system. If you have a professional interest in Web content distribution, or Web application development, I believe this book deserves a spot on your shelf.

You can purchase HTTP: The Definitive Guidefrom bn.com. Slashdot welcomes readers' book reviews -- to see your own review here, read the book review guidelines, then visit the submission page.

Comments

Re:I say, xerithane@nerdfarm.org

[robi2106]

Someone must be trying to get a spam crawler to pick up these addresses.

not fun at all

robi

Why do they always forget to mention

[Axe]

People here who made the web happen? They are the reason standards started and evolved in a way they did - WWW was "a collabaration tool for high-energy physics" after all. BTW - we should invite them to do an interview here on Slashdot.