How to activate JMX on a JVM for access with jconsole?
12 Answers
The relevant documentation can be found here:
http://java.sun.com/javase/6/docs/technotes/guides/management/agent.html
Start your program with following parameters:
-Dcom.sun.management.jmxremote
-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
For instance like this:
java -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 \
-jar Notepad.jar
-Dcom.sun.management.jmxremote.local.only=false
is not necessarily required
but without it, it doesn't work on Ubuntu. The error would be something like
this:
01 Oct 2008 2:16:22 PM sun.rmi.transport. customer .TCPTransport$AcceptLoop executeAcceptLoop
WARNING: RMI TCP Accept-0: accept loop for ServerSocket[addr=0.0.0.0/0.0.0.0,port=0,localport=37278] throws
java.io.IOException: The server sockets created using the LocalRMIServerSocketFactory only accept connections from clients running on the host where the RMI remote objects have been exported.
at sun.management.jmxremote.LocalRMIServerSocketFactory$1.accept(LocalRMIServerSocketFactory.java:89)
at sun.rmi.transport. customer .TCPTransport$AcceptLoop.executeAcceptLoop(TCPTransport.java:387)
at sun.rmi.transport. customer .TCPTransport$AcceptLoop.run(TCPTransport.java:359)
at java.lang.Thread.run(Thread.java:636)
see http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6754672
Also be careful with -Dcom.sun.management.jmxremote.authenticate=false
which
makes access available for anyone, but if you only use it to track the JVM on
your local machine it doesn't matter.
Update:
In some cases I was not able to reach the server. This was then fixed if I set this parameter as well: -Djava.rmi.server.hostname=127.0.0.1
Running in a Docker container introduced a whole slew of additional problems for connecting so hopefully this helps someone. I ended up needed to add the following options which I'll explain below:
-Dcom.sun.management.jmxremote=true
-Dcom.sun.management.jmxremote.local.only=false
-Dcom.sun.management.jmxremote.authenticate=false
-Dcom.sun.management.jmxremote.ssl=false
-Djava.rmi.server.hostname=${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.
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.
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.
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.
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
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
.
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.
RUN LOCAL PROCESS JCONSOLE using Remote Process option
To run locally, this worked for me -
I added this in my vm args -
-Dcom.sun.management.jmxremote=true
-Dcom.sun.management.jmxremote.port=6001
-Dcom.sun.management.jmxremote.authenticate=false
-Dcom.sun.management.jmxremote.ssl=false
-Djava.rmi.server.hostname=localhost
-Dcom.sun.management.jmxremote.rmi.port=6001
I opened JConsole via Intellij Terminal
It was showing me all PID's in grey in local
So I selected remote process and logged in using host - localhost:6001
Keep empty username & password
Then click connect
- Make sure no other process is running on port 6001. You can also use other ports.