If you missed it, Scott Oaks has put out a GlassFish Tuning Primer in his blog. He points to the full performance-tuning chapter in the GlassFish docs - but provides a concise a quick cheatsheet in his entry. If you are interested in past-and-present details on GlassFish, visit the GlassFish web site and also select the image on the right for the latest presentation on it. Note that the best place to get started with Glassfish is at the Getting Started site.