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
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