How to configure heap size for WebSphere application server

This post describes some ways to configure the heap size for WebSphere application server.

Note: The instructions mentioned in this post have been tested on WebSphere 8.5.

Note: This post does not describe all possible ways of configuring the heap size. For example, it does not describe how to set the heap size using wsadmin scripts.

Method 1: Using the administrative console

Open the administrative console.

Navigate to Servers > Server Types > WebSphere application servers > <servername>

Navigate to Server Infrastructure > Java and Process Management > Process Definition

Navigate to Additional Properties > Java Virtual Machine > General Properties

Define the values (in MB) for ‘Maximum heap size’ and/or ‘Initial heap size’.

Restart the server.

Note: If the heap size is already low, the administrative console might not open. In such cases, use some other method to configure the heap size.

Method 2: By editing the configuration files

This method should be used with caution.

Search for a file named server.xml in your WebSphere installation.

Generally, the location of this file is as follows:


Select the server.xml specific to your server and edit it to add/modify/delete the attributes @initialHeapSize and @maximumHeapSize of the element <jvmEntries> The value of these attributes is the heap size in MB.

For example:

<jvmEntries ... initialHeapSize="2048" maximumHeapSize="3072" ...>

Restart the server after saving the changes to server.xml.


1. Tuning the IBM virtual machine for Java –

This entry was posted in Application Server, Java, Java EE, WebSphere and tagged , , . Bookmark the permalink.

2 Responses to How to configure heap size for WebSphere application server

  1. Just one quick question … are the initial and maximum heap size settings equivalent to JVM args -Xms and -Xmx? Thanks,

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