[java] How to activate JMX on my JVM for access with jconsole?

How to activate JMX on a JVM for access with jconsole?

along with below command line parameters ,

-Dcom.sun.management.jmxremote.port=9999
-Dcom.sun.management.jmxremote.authenticate=false
-Dcom.sun.management.jmxremote.ssl=false

Sometimes in the linux servers , imx connection doesn't get succeeded. that is because , in cloud linux host, in /etc/hosts so that the hostname resolves to the host address.

the best way to fix it is, ping the particular linux server from other machine in network and use that host IP address in the

-Djava.rmi.server.hostname=IP address that obtained when you ping that linux server.

But never rely on the ipaddress that you get from linux server using ifconfig.me. the ip that you get there is masked one which is present in the host file.

First you need to check if your java process is already running with JMX parameters. Do this:

ps -ef | grep java

Check your java process you need to monitor. If you can see jmx rmi parameter Djmx.rmi.registry.port=xxxx then use the port mentioned here in your java visualvm to connect it remotely under jmx connection.

If it's not running through jmx rmi port then you need to run your java process with below mentioned parameters :

-Djmx.rmi.registry.port=1234 -Djmx.rmi.port=1235 -Dcom.sun.management.jmxremote.authenticate=false -Dcom.sun.management.jmxremote.ssl=false

Note: port numbers are based on your choice.

Now you can use this port for jmx coneection. Here it is port 1234.

Note, Java 6 in the latest incarnation allows for jconsole to attach itself to a running process even after it has been started without JMX incantations.

If that is available to you, also consider jvisualvm as it provides a wealth of information on running processes, including a profiler.

I'm using WAS ND 7.0

My JVM need all the following arguments to be monitored in JConsole

    -Djavax.management.builder.initial= 
    -Dcom.sun.management.jmxremote 
    -Dcom.sun.management.jmxremote.port=8855 
    -Dcom.sun.management.jmxremote.authenticate=false 
    -Dcom.sun.management.jmxremote.ssl=false

On Linux, I used the following params:

-Djavax.management.builder.initial= 
-Dcom.sun.management.jmxremote 
-Dcom.sun.management.jmxremote.port=9010 
-Dcom.sun.management.jmxremote.local.only=false
-Dcom.sun.management.jmxremote.authenticate=false 
-Dcom.sun.management.jmxremote.ssl=false

and also I edited /etc/hosts so that the hostname resolves to the host address (192.168.0.x) rather than the loopback address (127.0.0.1)

Run your java application with the following command line parameters:

-Dcom.sun.management.jmxremote.port=8855
-Dcom.sun.management.jmxremote.authenticate=false
-Dcom.sun.management.jmxremote.ssl=false

It is important to use the -Dcom.sun.management.jmxremote.ssl=false parameter if you don't want to setup digital certificates on the jmx host.

If you started your application on a machine having IP address 192.168.0.1, open jconsole, put 192.168.0.1:8855 in the Remote Process field, and click Connect.

I had this exact issue, and created a GitHub project for testing and figuring out the correct settings.

It contains a working Dockerfile with supporting scripts, and a simple docker-compose.yml for quick testing.

The below options works for me:

-Dcom.sun.management.jmxremote=true
-Dcom.sun.management.jmxremote.port=9010
-Dcom.sun.management.jmxremote.rmi.port=9010
-Dcom.sun.management.jmxremote.local.only=false
-Dcom.sun.management.jmxremote.authenticate=false
-Dcom.sun.management.jmxremote.ssl=false
-Djava.rmi.server.hostname={host name}

and remember to open 9010 port in the server

sudo ufw allow 9010/udp
sudo ufw allow 9010/tcp
sudo ufw reload

Running in a Docker container introduced a whole slew of additional problems for connecting so hopefully this helps someone. I ended up needed to add the following options which I'll explain below:

-Dcom.sun.management.jmxremote=true
-Dcom.sun.management.jmxremote.local.only=false
-Dcom.sun.management.jmxremote.authenticate=false
-Dcom.sun.management.jmxremote.ssl=false
-Djava.rmi.server.hostname=${DOCKER_HOST_IP}
-Dcom.sun.management.jmxremote.port=9999
-Dcom.sun.management.jmxremote.rmi.port=9998

DOCKER_HOST_IP

Unlike using jconsole locally, you have to advertise a different IP than you'll probably see from within the container. You'll need to replace ${DOCKER_HOST_IP} with the externally resolvable IP (DNS Name) of your Docker host.

JMX Remote & RMI Ports

It looks like JMX also requires access to a remote management interface (jstat) that uses a different port to transfer some data when arbitrating the connection. I didn't see anywhere immediately obvious in jconsole to set this value. In the linked article the process was:

• Try and connect from jconsole with logging enabled
• Fail
• Figure out which port jconsole attempted to use
• Use iptables/firewall rules as necessary to allow that port to connect

While that works, it's certainly not an automatable solution. I opted for an upgrade from jconsole to VisualVM since it let's you to explicitly specify the port on which jstatd is running. In VisualVM, add a New Remote Host and update it with values that correlate to the ones specified above:

Then right-click the new Remote Host Connection and Add JMX Connection...

Don't forget to check the checkbox for Do not require SSL connection. Hopefully, that should allow you to connect.

Step 1: Run the application using following parameters.

-Dcom.sun.management.jmxremote.port=9999 
-Dcom.sun.management.jmxremote.authenticate=false 
-Dcom.sun.management.jmxremote.ssl=false

Above arguments bind the application to the port 9999.

Step 2: Launch jconsole by executing the command jconsole in command prompt or terminal.

Select ‘Remote Process:’ and enter the url as {IP_Address}:9999 and click on Connect button to connect to the remote application.

You can refer this link for complete application.