Increasing the Java virtual machine heap size using scripting

 

For some servers, it may be required to specify a Java virtual machine (JVM) heap size greater than the default. You can increase the heap size of the JVM using the console, the wsadmin tool, or a Java client.

 

About this task

If you are using a JVM platform that is running on a 32-bit AIX system, perform this task if the appserver, deployment manager, or node agent require a greater heap size.

 

Procedure

1. Set attributes that control the heap size for the JVM associated with the server. This can be done using the console, the wsadmin tool, or a Java client.

2. Perform one of the following to increase the heap size of the JVM:

   • Create a script to launch the server. Use the -script option with the command that you are using to start the target server, for example, the startServer, startManager, or startNode commands. This will generate a script for used to to launch the target server in the future.

   • Manually set the environment variables before starting the target server with the startServer, startManager, or startNode commands. With the following settings, you can specify a maximum heap size for the JVM of 11 multiplied by 256 megabytes:

     export IBM_JVM_LDR_CNTRL_NEW_VALUE=MAXDATA=0XB0000000@DSA export LDR_CNTRL=MAXDATA=0XB0000000@DSA
     
     

   • Use the AdminTask object. For example:

     Use Jython:

     AdminTask.setJVMMaxHeapSize ('[-interactive]')
     

     Use Jacl:

     $AdminTask setJVMMaxHeapSize {-interactive}
     

   For additional information on AIX address space management, view the following sources:

   • IBM 32-bit SDK for AIX, Java 2 Technology Edition, V1.4 - User Guide

   • Getting more memory in AIX for your Java applications

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Configure servers with scripting