You may need to adjust the Java Virtual Memory (JVM) memory settings depending on the default settings of the application server (Apache Tomcat). If Apache Tomcat is configured during the WebFOCUS installation, then these JVM settings are configured automatically.

The most common JVM settings that need to be configured involve the size of the Java heap and stack, which determine the available memory for Java programs and the JVM. Errors can occur if not enough memory is available. The heap size also impacts performance, since this determines how often garbage collection occurs.

The following list shows the most common JVM settings related to memory. You can replace the ### placeholder with any size (in megabytes) that you wish to set:

• -Xmx###M

  Sets the maximum Java heap size. It is common to make this 1/4 of the system RAM.

• -Xms###M

  Sets the initial Java heap size. It is common to make this 1/8 of the system RAM.

• -Xss###M

  Sets the Java thread stack size. You do not need to set this unless you are fine-tuning your environment.

The size is normally set in megabytes. For example:

-Xms256M
-Xmx512M

To view your current JVM settings, access the following console:

http://hostname:port/ibi_apps/diagnostics/jvmstatus.jsp

where:

hostname

Is the host name or IP address of the system where WebFOCUS is installed.

port

Is the port number of the system where WebFOCUS is being hosted.

Optimum sizes vary depending on your total memory, the requirements of your application, how many other processes require memory, the type of JVM, and other considerations. A good starting point is to set the minimum to 1/8 of the total RAM and set the maximum to 1/4 of total RAM.

The location of where to set these and other JVM options, depend on your application server.

• For Apache Tomcat, the sizes are set automatically if the WebFOCUS installation configures Tomcat.
• For other application servers, see your application server documentation.