Website Optimization

Chapter 9. Advanced Web Performance Optimization

Now that you’ve learned how to crunch your content, let’s look at some more advanced server- and client-side techniques for increasing web performance.

On the server side, this chapter explores methods that you can use to boost performance by:

• Optimizing parallel downloads

• Caching frequently used objects

• Using HTTP compression

• Deploying delta encoding

• Rewriting URIs with mod_rewrite

On the client side, we’ll investigate procedures that you can use to improve the speed of content delivery. Although these techniques take some additional effort, they boost both perceived and actual web page speed.

Server-Side Optimization Techniques

This section explores some server-side techniques that you can use to boost your site’s performance. Note that some of these techniques are hybrids, combining server-side settings with concomitant client-side modifications. For more on server-side performance optimization, you can also check out Web Performance Tuning: Speeding Up the Web, by Patrick Killelea (O’Reilly).

Optimizing Parallel Downloads

The HTTP 1.1 specification recommends that browsers limit downloads to two objects per hostname. This recommendation was created in 1999, in the days of dial-up and less robust proxy servers. Most browsers default to this limit. Although users can change these defaults, most don’t bother to do so. For sites hosted on one domain, the result is slower load times with objects loaded two at a time.

Now that bandwidth ...