GlassFish monitoring

As of Q4 2009 Yenlo offers GlassFish Support.
As has been described in an earlier post we have developed our own GlassFish monitoring solution which is used in conjunction with Oracle Enterprise Manager.
The main reasons for developing a custom solution is that there were no readily available solutions which could fulfill our requirements. The solutions which were available are not tailored towards GlassFish which gave us insufficient means to monitor the components and parts of GlassFish we deemed necessary for accurate and adequate monitoring of the GlassFish environment.

Our monitoring plugin communicates with GlassFish through the JMX standard and also uses the GlassFish specific AMX APIs.
Both these APIs provide interfaces and classes to retrieve detailed information about the environment in which the MBeans (JMX components which expose status information) are running. GlassFish registers its MBeans within its own JMX server instance allowing external clients to retrieve that information.

GlassFish allows various levels of monitoring of its components. These levels are configurable within the admin console of GlassFish. By setting these monitoringlevels you gain control over the amount of information which is gathered by the GlassFish MBeans and which you can retrieve from GlassFish. As more information is retrieved the performance impact on the environment will also increase.

Recently we have expanded the functionality of our plugin to monitor the various heapsizes of instances within the GlassFish environment. The plugin now gives us information about the current status of the heapsize of the various JVMs within a GlassFish domain / cluster.
Monitoring the heapsizes of these instances enables us to pro-actively detect potential problems to the environment. Due to thresholds set within Oracle Enterprise Manager we get warned well before an actual problem is occurring so that we can mitigate or fix the problem from happening and save our customers downtime and other problems.

If you would like to do some monitoring yourself have a look at the JMX API and the AMX API of both GlassFish V2 and V3.

To do basic monitoring on GlassFish use jconsole which is part of the Java SE distribution. JConsole offers great insight in the status of a GlassFish server.