Working With JVM Heap Size

Adjusting the JVM heap size settings can improve performance in some situations, however, the default settings are typically adequate for most situations.

To access the JVM heap size properties:

  1. In the Administrative Console, select Servers, Server Types, WebSphere application servers, and click on your server in the resource list.

  2. Select the Configuration tab, and in the Server Infrastructure section expand Java and Process Management, and click Process definition.

  3. In the Additional Properties, click Java Virtual Machine.

The JVM heap size properties are:

Property

Description

Initial heap size

The initial heap available to the JVM.

If blank, the system assumes the default value of 50 MB.

Maximum heap size

The maximum heap available to the JVM.

If blank, the system assumes the default value of 256 MB.

IBM recommends that if you determine that garbage collection occurs more than desired, increase the Maximum heap size value.