JVM profiles (JVMPROFILE attribute)

CICS can use various options when creating a JVM. You can create different sets of options, known as JVM profiles, that produce JVMs that are suitable for different applications. The JVM profiles contain the Java launcher options, and also reference a JVM properties file containing the system properties for the JVM. (System properties are key name and value pairs that contain basic information about the JVM and its environment.) Among other things, the JVM properties file determines the security properties of the JVM. CICS supplies sample JVM profiles and JVM properties files, and in many cases, you may find that you can use these unchanged.

When CICS receives a request to run a Java program, a JVM profile is named on the PROGRAM resource definition for the Java program. (How CICS locates the PROGRAM resource definition to create a JVM explains how CICS locates the PROGRAM resource definition for different types of request.) CICS creates a JVM using the options given in this JVM profile, and the system properties given in the JVM properties file that the JVM profile references. Alternatively, CICS finds a free JVM that it has already created with these options and system properties.

A JVM profile specifies, among other things: The CICS® System Definition Guide has the full list of options that you can specify using a JVM profile.
Note: In some earlier versions of CICS, you could use the -Xquickstart option (specified using the Xservice option) in a JVM profile to reduce the startup time for the JVM. However, with improvements in JVM technology, the -Xquickstart option is now permanently enabled, and specifying -Xquickstart in a JVM profile has no effect.
A JVM properties file specifies, among other things: The CICS System Definition Guide has the full list of options that you can specify using a JVM properties file.

Setting up JVM profiles and JVM properties files tells you how to set up suitable JVM profiles and JVM properties files to meet the needs of your applications.