How to access JMX (Java Beans) from a process running in docker container
Why is it so hard to connect to a JMX port (using JConsole), when a process is run using Docker.
Of course I have exposed the JMX port to the host, and even used Sun specific options while running the Java process (following the instructions from http://ptmccarthy.github.io/2014/07/24/remote-jmx-with-docker/ ).
I am able to telnet to the host ip and the exposed JMX port, which tells that it is accessible. But I can’t figure out a way to use JConsole and connect to the JMX service running in the container.
-Djava.rmi.server.hostname=$JMX_HOSTNAME -Dcom.sun.management.jmxremote.port=$JMX_PORT -Dcom.sun.management.jmxremote.rmi.port=$JMX_PORT
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In the past, the two ports had to be different. Please try that for a start.
If thats not working:
Tomcat offers an additional component to set the second port mentioned, the JMX Remote Lifecycle Listener.
Please have a look at:
I´m using this setting with catalina-jmx-remote.jar in my tomcat/lib directory to get through:
-Dcom.sun.management.jmxremote -Dcom.sun.management.jmxremote.ssl=false -Djava.rmi.server.hostname=localhost -DrmiRegistryPortPlatform=10381 -DrmiServerPortPlatform=10380
Plus these, but you wouldn´t need them in a dev environment.
-Dcom.sun.management.jmxremote.password.file=/home/tomcat/jmxremote.password -Dcom.sun.management.jmxremote.access.file=/home/tomcat/jmxremote.access -Dcom.sun.management.jmxremote.authenticate=true
What you currently have looks correct. To at least try and get it working, i’d try disabling auth & ssl. Then, once you get it working, think about re-enabling any security you require:
Indeed, you need those 2 ports to be different. One port is for the RMI registry and the other for the remoting protocol.
When specifying the URL to connect to the server from jconsole/visualvm use the port set in “-Dcom.sun.management.jmxremote.port” on the server side.