We switched to using the AppMon agent on our Java servers. After doing so when trying to do a trending or selective memory dump it would just hang and never complete a full memory dump worked. We switched back to the Classic agent and the trending/selective memory dumps worked.
Is this some limitation of the AppMon agent or is there some other problem that could be causing this?
Then I would look on the server side in the server.0.0.log file to see if there's any messages related to this activity. The memory dumps report some nice messages in the agent log and if you're not getting any then I'm guessing the 'message' isn't getting to the agent. If nothing useful is found in the server.0.0.log, then I'd open a support case.