3 Replies Latest reply on Apr 25, 2013 3:45 AM by Stephen Coy

    Heap size parameter changed in JBoss EAP 6.1.0 Alpha

    Sudhir Shakya Newbie

      The last version of JBoss AS 7.1.3 had the following parameters - "-Xms64m -Xmx512m".

      The latest version JBoss EAP 6.1.0 Alpha, the same parameter has been changed to "-Xms1303m -Xmx1303m".

      Is there a reason the new version of the application server needs so high memory? Also, I found it strange that the min and max heap size have the same values.

        • 1. Re: Heap size parameter changed in JBoss EAP 6.1.0 Alpha
          Peter Johnson Master

          I can't seak to the size picked (except that might be a resonable max value for the heap when using a 32-bit JVM). But as for setting the min and max heap to the same that is a standard best practice for production environments, and EAP is meant for production environments (AS is meant more for development). In a production environment is is assume that either only the app server will be running on the box, or that there is a well-defined set of applications running on that box and that the memory for those applications has all be taken into account to size the box.

          • 2. Re: Heap size parameter changed in JBoss EAP 6.1.0 Alpha
            Tomaz Cerar Master

            Hi,

             

            1303M is about(give or take a bit) the maximum heap size you can configure on 32bit jvm.

            This is why this was picked.

            And as Peter said, setting Xms to same size as Xmx is usualy the best option performance wise, so that jvm does not need to compact heap when resizing it (when xms is smaller than xmx).

            Also as Peter said, for production enviroment this is best practice also the size.

             

            If your application does not need that much, then just change configuration to best fit your needs.

            Jboss itself will run happly in less than Xmx64m(i think even below 32m) but beyond that it all depends on application you are deploying

             

             

            --

            tomaz

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            • 3. Re: Heap size parameter changed in JBoss EAP 6.1.0 Alpha
              Stephen Coy Master

              ~1300M would be a 32 bit Windows limitation. You can typically get ~1800M or more using 32 bit linux on the same hardware.