JVM Jrockit performance Tuning

Setting JRockit Virtual Machine (JVM) Arguments

JVM arguments are set in the setDomainEnv.sh file on Unix operating systems and setDomainEnv.cmd on Windows operating systems. The setDomainEnv file is located in the <domain_dir>/bin directory.

"Tuning Java Virtual Machines (JVMs)"

·        Heap size: If the server is overloaded, that is, garbage is collected or out of memory error occurs frequently, then increase the heap size as appropriate to your server's available physical memory.

The following parameters can be modified in the server's startup command or through the Administration Console to increase heap size:

jrockit vm: -Xms2048M -Xmx2048M -Xns512M

hotspot vm: -Xms2048M -Xmx2048M -XX:MaxPermSize512M

·        Garbage Collection

In some usecase scenarios modifying the following garbage collection settings may improve performance:

-XX:+UseParallelOldGC -XX:+ParallelRefProcEnabled

-XX:SoftRefLRUPolicyMSPerMB=0

Note that the values of -Xmn and SoftRefLRUPolicyMSPerMB(0-1000) can aslo be adjusted in accordance with the respective application memory settings and requirements. For example:

-XX:PermSize=512m -XX:MaxPermSize=512m -Xmn512m

-Dweblogic.threadpool.MaxPoolSize=25