Removal of support for CICS Transaction Server for OS/390®, Version 1 Release 3 JVMs

The JVM introduced in CICS® TS 1.3 is not supported. Any Java™ programs that ran under CICS TS 1.3, and were not previously migrated for CICS Transaction Server for z/OS®, Version 2 Release 2, should be migrated to Java 2 to run under the JVM provided by the IBM® Software Developer Kit for z/OS, Java 2 Technology Edition, Version 1.4.2 or later, which features the persistent reusable JVM technology. Application migration issues are discussed at:
http://java.sun.com/j2se/1.4.2/compatibility.dital
http://java.sun.com/j2se/1.4/compatibility.dital
http://java.sun.com/products/jdk/1.3/compatibility.dital#incompatibilities1.3
and
http://java.sun.com/products/jdk/1.2/compatibility.dital

Support for the JVM provided by the IBM Software Developer Kit for z/OS, Java 2 Technology Edition, Version 1.4.2 or later, completely replaces the JVM support provided in CICS TS 1.3. However, you can modify a JVM to run as a single-use JVM and not attempt serial reuse. A single-use JVM is initialized, is used to run a single Java program, and then is automatically destroyed without attempting a JVM reset. The single-use JVM is like the earlier JVM that was supported by CICS in CICS TS 1.3. New Java applications should not be developed in such a way that they can only run in a single-use JVM.

You can modify a JVM to be a single-use JVM by specifying either REUSE=NO, or the older option Xresettable=NO, in the JVM profile. This might be necessary to run programs that use Java interfaces, such as multi-threading, that make JVMs unresettable. Single-use JVMs (REUSE=NO) has more information about the appropriate use of single-use JVMs.

For a single-use JVM, you can, if you want, invoke the user-replaceable program DFHJVMAT to change JVM options. The CICS Customization Guide tells you how to use DFHJVMAT. DFHJVMAT cannot be used with any type of JVM other than the single-use JVM. If you need to change JVM options for other types of JVM, do so by customizing the JVM profile and JVM properties file for the JVM. Setting up JVM profiles and JVM properties files explains how to do this.