Instrumenting Existing App with JMX

Hi,

It depends what you want to monitor in your application.

If you want to monitor JVM resource consumption, then you simply need to start the JVM JMX agent.

If you're running on JDK 6 with a Sun's JVM then you only need to start JConsole from

the same (user/machine), connect to your running process, and you will be able to

see all the data gathered by the JVM Monitoring & Management API. (local management)

If you're running on JDK 5, and/or if you want to monitor from a different (user/machine)

then start your app with the appropriate flags so that the JMX agent is enabled at start-up,

and then connect to it with JConsole.

see http://java.sun.com/developer/technicalArticles/J2SE/monitoring/

If you want to expose data which is specific to your application e.g. number of blah received, then you will need to write an MBean that will expose that data. You will also

need to register that MBean in the platform MBeanServer, and you will need to start your

application in one of the two ways exposed above.

Your application classes need not to be aware of the management layer, but you will

need to insert code at some point (e.g. in main()) that will register your new MBeans.

You could do this - for instance - by providing an alternate main:MyAppMainClass {

public static void main(String[] args) {...}

}

MyNewAppMainClass {

public static void main(String[] args) {

// register my new MBeans...

...

// start my app

MyAppMainClass.main(args);

}

}

You will find a lot of advices and information on developing management interfaces with JMX in the new JDK 6 JMX Sample - see

http://blogs.sun.com/jmxetc/entry/an_advanced_jmx_example_for

And for the basics, you may want to follow the new JDK 6 Tutorial Trail:

http://java.sun.com/docs/books/tutorial/jmx/

You will also find a bunch of links to JMX docs here:

http://blogs.sun.com/jmxetc/entry/the_new_jmx_tutorial_trail

Finally, <a href="http://weblogs.java.net/blog/emcmanus">Eamonn McManus</a>, JMX spec lead, did a talk at Java One 2006 where he evoked the different ways to link MBeans to application objects.

http://developers.sun.com/learning/javaoneonline/2006/coreplatform/TS-3523.html

Hope this will help you!

-- daniel

JMX, SNMP, Java, etc...

http://blogs.sun.com/jmxetc

dfuchsa at 2007-7-8 1:40:08 >