0 Replies Latest reply on Sep 20, 2014 10:41 AM by Mylos Kathos

    Actual amount of memory used by JBoss AS ?

    Mylos Kathos Master

      Hi all!

      I have the requirement to start a JBoss AS 7 instance with min and max 512MB of memory. I've correctly settled the parameters in standalone.conf, so that at starup I have:

      =========================================================================

        JBoss Bootstrap Environment

      JAVA_OPTS:  -server -Xms512m -Xmx512m -XX:MaxPermSize=256m -Djava.net.preferIPv4Stack=true -Djboss.modules.system.pkgs=org.jboss.byteman -Djava.awt.headless=true -agentlib:jdwp=transport=dt_socket,address=8787,server=y,suspend=n

      However, taking a look at Linux top command I can see different numbers for the Virtual Memory used by the jboss process:

       

        PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND           

      1143 root      20   0 66928  21m 6052 S  7.4  1.1   0:10.35 Xorg              

      2736 jboss     20   0  917m 249m  15m S  0.2 12.4   0:11.51 java    

      2165 jboss     20   0  119m  14m 9828 S  3.0  0.7   0:03.21 lxterminal        

        431 syslog    20   0 28932 1284 1036 S  0.2  0.1   0:00.10 rsyslogd          

      1433 jboss     20   0 77280  22m  16m S  0.2  1.1   0:06.07 vmtoolsd          

      2034 root      20   0 35136 4248 3476 S  0.2  0.2   0:00.60 vmtoolsd     

      It seems the jboss process is using about 917MB of Virtual Memory. Is my understanding of top correct ? why such a difference with the JAVA_OPTS I've set ?   

      Thanks!

      Mylos