Sun GlassFish is one of the leading open source J2EE application servers. ManageEngine Applications Manager helps in monitoring the performance and availability of GlassFish Application Server.
ManageEngine Applications Manager diagnoses, notifies, and corrects performance and availability problems with App Servers, Databases, Servers, WebServices, etc.
Applications Manager has the capability to build dashboards for JMX MBeans. This along with Java Runtime Monitoring and URL Sequence Monitoring is used to monitor Glassfish App Server.
Java Runtime Monitor provides out-of-the-box remote monitoring and management on Java platform and of applications that run on it. Some metrics that can be monitored - Process Memory stats, Virtual Memory stats, Thread stats etc.
Record & Playback HTTP Requests: It checks pages with dynamically generated information, enhancing interactive transactions such as logging into a login page, creating an account using a web form, instructing the application to perform some action, etc.
J2EE Web Transactions Monitor helps to better visualize J2EE Web Transactions end to end, with performance metrics of all components starting from URLs to SQL queries.
A detailed step by step procedure on how to monitor GlassFish is provided in Forums.