Apache: The Definitive Guide, 3rd Edition

Criteria for Choosing a Web Server

What do we want a web server to do? It should:

• Run fast, so it can cope with a lot of requests using a minimum of hardware.

• Support multitasking, so it can deal with more than one request at once and so that the person running it can maintain the data it hands out without having to shut the service down. Multitasking is hard to arrange within a program: the only way to do it properly is to run the server on a multitasking operating system.

• Authenticate requesters: some may be entitled to more services than others. When we come to handling money, this feature (see Chapter 11) becomes essential.

• Respond to errors in the messages it gets with answers that make sense in the context of what is going on. For instance, if a client requests a page that the server cannot find, the server should respond with a “404” error, which is defined by the HTTP specification to mean “page does not exist.”

• Negotiate a style and language of response with the requester. For instance, it should — if the people running the server can rise to the challenge — be able to respond in the language of the requester’s choice. This ability, of course, can open up your site to a lot more action. There are parts of the world where a response in the wrong language can be a bad thing.

• Support a variety of different formats. On a more technical level, a user might want JPEG image files rather than GIF, or TIFF rather than either of those. He might want text in vdi format rather than ...