This book provides an in-depth tutorial on administering the GlassFish application server. Every chapter starts with a clear discussion of the involved concepts, followed by step-by-step instructions on how to perform the administrative task. Clear illustrations and complete working code examples are used to help you visualize the relevant topics. If you are a Java EE application developer and architect who builds and deploys Java EE, Ruby on Rails, and other supported applications for the GlassFish Application Server, then this book is for you. This book is also very valuable if you are an administrator responsible for maintaining the GlassFish Server runtime. Basic knowledge of Java EE 5 is assumed but you need not have any previous knowledge of GlassFish. Those who already know the basics of GlassFish will still find this book useful as they will gain knowledge of administration tasks.