1.3 KiB
JMX Monitoring
Java offers Java Management Extensions (JMX) which is built into the JDK since Java 6. We can use this to monitor the state of a live server VM without the need to attach a debugger or profiler and can thus gain at least some high-level insights into the VM's health status.
Our first JMX MXBean is com.sap.sailing.server.RacingEventServiceMXBean for which an instance is created and registered by the com.sap.sailing.server.impl.Activator and which reads properties from the RacingEventService instance. This can also be used as an example for further MXBeans that make other aspects of our server manageable and monitorable in the console.
In order to gain access to the VM using JMX it needs to be started with a few system properties set:
-Dcom.sun.management.jmxremote
You can then launch your local jconsole tool from the JDK to connect to the remote VM. Ideally, you launch a VNC server on the machine running the Java VM that you want to monitor and execute jconsole in a terminal running in that VNC server. This avoids firewall hassle which can be pretty difficult to handle when trying to monitor a JMX-enabled VM remotely.
