3 Replies Latest reply on Jun 14, 2014 6:19 AM by wdfink

    JBoss 7.1.1 strange memory usage

    festarbg

      Hello,

      I was profiling our Spring MVC + Hibernate app when I discovered a strange behaviour - the memory kept getting higher and then suddenly dropping (ano not because of the GC). Then I tried monitoring only JBoss, without deploying our app. I've applied a screenshot to demonstrate - the memory drops from 150M to 25M and does this continuously.

      The options with which JBoss is started:

      -Xms256M -Xmx1024M -XX:MaxPermSize=512M -XX:+CMSClassUnloadingEnabled -XX:+UseConcMarkSweepGC

       

      I tried clearing the tmp and deployment files and restarting but the behaviour is the same. Any ideas about it will be appreciated.

        • 1. Re: JBoss 7.1.1 strange memory usage
          wdfink

          Is the same happen if you start a fresh 7.1.1?

          If not there should be some configuration or deployment which do something.

          You might monitor threads and take thread dumps to see what is active

          • 2. Re: JBoss 7.1.1 strange memory usage
            festarbg

            Yes, the same thing happens with a brand new and untouched JBoss installation (7.1.1. Final). This time the memory starts from 16M and goes to 80M and then again and again. Is this something I should be worried about (is it a wanted behaviour)?

            • 3. Re: JBoss 7.1.1 strange memory usage
              wdfink

              No, as if the server is idle there is still some activity and object are created. If the memory is not blown up and you did not see strong CPU use this is fine and a normal behaviour of Java applications