Web Performance Tuning

How Fast a Server Do You Need?

Given a certain network bandwidth, how fast a server do you need? More server disk speed, bus speed, and CPU speed all cost money. From the network bandwidth, you have an upper limit on the HTTP server hardware you need for serving static content such as HTML and images. Remember that there’s no point in buying server hardware that has vastly more throughput capacity than the network it’s connected to if you can’t use that server’s throughput. The web server software and operating system determine how efficiently you can use your server hardware. In practice, HTTP server software is not a bottleneck. For example, Apache running on Linux on a low-end Pentium machine can fill a 10Mbps line with static HTML content. If a significant load is put on your server, it will be from dynamic content generation, such as CGIs, Java servlets, and database queries. If you have any dynamic content, you should size your server around that.

The whole connection time for an Internet HTTP transfer is typically 2 to 20 seconds, most of which is usually caused by modem and Internet bandwidth and latency limitations. While this may be frustrating, it does leave quite a bit of breathing room for the server. It makes little sense to insure that a lightly loaded server can generate a response to an HTTP request in one millisecond if the network is going to consume thousands of milliseconds.

This is not to say that web server performance on the Internet is not important; without ...