Profiling a running Java application in command line

Question

I profile running Java applications often with VisualVM but it needs X to run on the machine.

I know I can connect through management port but that will be an offlin

Answer 1

One way to profile an "already started" JVM is to aggregate multiple jstacks taken over time.

You can for instance parse and display them as a FlameGraph (see details at the various answers for that link, I won't redundantly include them here).