Like any other server environment, sometimes, the GlassFish Server environment can go wrong. Errors could come in many different forms. For example, the GlassFish Server may not be able to start if there is port number conflict; or an application may exhibit strange behavior when the server is under heavy load. The official GlassFish troubleshooting guide (http://docs.sun.com/app/docs/doc/820-4339) maintains a list of commonly occurred problems, and also provides the solution to them. We strongly recommend that you get familiar with this document.
In our experience, the most difficult issues occur in applications and their configuration. In other words, the GlassFish Server is in a running state, but the deployed applications are not producing desired results. What makes the matter more difficult is that many application or configuration related errors do not surface until they are running under some unexpected circumstances, such as very heavy server...