JMX, SNMP, Java, etc...

... So many words I couldn't even put them all in the title...

I've been asked several times how to make my example of javaagent which starts a firewall friendly JMX RMI Connector work on JDK 5. Well, here is how. However, beware of the catch: if you use SSL and want to connect with JConsole then you need to use Java 6 JConsole on the client side.

JMX is a wonderful tool to monitor and troubleshoot running applications. The new JDK 6 Attach API makes it very easy to attach to a running Java process, and start a JMX agent that will expose monitoring and configuration data to JMX consoles - like JConsole. However, there are some situations where you wish to start a JMX agent on demand, explore the monitoring data or diagnose the probable cause of an observed problem, and then close your JMX agent, leaving the application just how you found it.

In this post, I will discuss a means by which you can upload and start such a remotely stoppable JMX agent. Here is how.

This post explains how you can configure your Java application to export a single port using JMX RMI Connector Server over SSL. This is particularly useful when your application is located behind a firewall, because you will only need to let through a single port. However, using a single port when SSL is enabled requires a little care, because it can only work if the same RMI Socket Factories are used everywhere: indeed the same port cannot be shared by two different RMI Socket Factories. So at the risk of boring you, here is my third post on the subject.