JVM profiles

JVM profiles are text files that contain Java™ launcher options and system properties, which determine the characteristics of JVMs. You can edit JVM profiles using any standard text editor.

When CICS® receives a request to run a Java program, the name of the JVM profile is passed to the Java launcher. The Java program runs in a JVM, which was created using the options in the JVM profile.

CICS uses JVM profiles that are in the z/OS® UNIX System Services directory specified by the JVMPROFILEDIR system initialization parameter. This directory must have the correct permissions for CICS to read the JVM profiles.

Sample JVM profiles

CICS includes several sample JVM profiles to help you configure your Java environment. They are customized during the CICS installation process. These files are used by CICS as defaults or for system programs.

A JVM profile lists the options that are used by the CICS launcher for Java. Some of the options are specific to CICS and others are standard for the JVM runtime environment. For example, the JVM profile controls the initial size of the storage heap and how far it can expand. The profile can also define the destinations for messages and dump output produced by the JVM. The JVM profile is named in the JVMPROFILE attribute in a JVMSERVER resource definition.

You can copy the samples and customize them for your own applications. The sample JVM profiles supplied with CICS are in the directory /usr/lpp/cicsts/cicsts61/JVMProfiles on z/OS UNIX.

Note: If you are unable to find the sample JVM profiles in /usr/lpp/cicsts/cicsts61/JVMProfiles, or the directory does not exist, then it is likely you have not run the DFHIJVMS job to populate the directories and create the JVM profiles. You can find this job in SDFHINST and it is documented in the Program Directory for CICS Transaction Server for z/OS. See Program Directories for more information.

Copy the samples from the installation directory to the directory that you specified in the JVMPROFILEDIR system initialization parameter. The sample JVM profiles in the installation location are overwritten if you apply an APAR that includes changes to these files. To avoid losing your modifications, always copy the samples to a different location before adding your own application classes or changing any options.

The following table summarizes the key characteristics of each sample JVM profile.

Table 1. Sample JVM profiles supplied with CICS
JVM profile	Characteristics
DFHJVMAX.jvmprofile	The supplied sample profile for an Axis2 JVM server. The JVM profile is specified on the JVMSERVER resource. CICS uses DFHJVMAX.jvmprofile to initialize the JVM server.
DFHJVMST.jvmprofile	The supplied sample profile for a JVM server for a Security Token Service. The JVM profile is specified on the JVMSERVER resource. CICS uses DFHJVMST.jvmprofile to initialize the JVM server.
DFHOSGI.jvmprofile	The supplied sample profile for an OSGi JVM server. The JVM profile is specified on the JVMSERVER resource. CICS uses DFHOSGI.jvmprofile to initialize the JVM server.
DFHWLP.jvmprofile	The supplied sample profile for a Liberty JVM server. The JVM profile is specified on the JVMSERVER resource. CICS uses DFHWLP.jvmprofile to initialize the Liberty JVM server.
EYUCMCIJ.jvmprofile	The supplied sample profile for a CMCI Liberty JVM server within CICPlex SM. The JVM profile is specified on the JVMSERVER resource. CICS uses EYUCMCIJ.jvmprofile to initialize the Liberty JVM server.
EYUSMSSJ.jvmprofile	The supplied sample profile for a CMCI Liberty JVM server in a single CICS region. The JVM profile is specified on the JVMSERVER resource. CICS uses EYUSMSSJ.jvmprofile to initialize the Liberty JVM server.