Just got back from a StartupCamp5 and the beginning of Sun’s JavaOne Conference. Was able to spend a few hours back in San Francisco, see some friends and family.

I’ve recently been working on performance tuning a set of application servers for optimal performance of a high volume website. YSlow is a Firefox Add-on that works in conjunction with the Firebug add-on that is intended to help you analyze and understand performance based on Yahoo.com’s rules of “High Performance Websites.”

If you work with the YSlow tool in a development environment you likely aren’t going to be using a Content Delivery Network (CDN) such as Akamai or Limelight Networks. Thus, you get a lower optimization score when testing. This can obviously be misleading, and there is a work around documented in Yahoo’s YSlow FAQ. The problem is that the documentation explains the work around must be configured via: “Go to about:config in Firefox. You’ll see the current list of preferences.” The issue/confusion is that many people don’t realize that “about:config” isn’t an option of your browser preferences, or preferences of your plug-ins. You must type “about:config” into the address bar of your browser to pull up these configuration parameters.

The YSlow plug-in itself is very useful. However, the documentation seems a bit lacking so hopefully I am able to save others who attempt to configure it some valuable time.