IBM® CICS® Transaction Server (CICS TS) has supported the deployment of Java applications since the 1990’s. In CICS TS V1.3 (1999), IBM introduced the Pooled JVM style of JVM infrastructure within CICS TS. This infrastructure was designed to be similar in nature to that which a CICS application developer for a language such as COBOL would be used to. It brought the benefits of the new Java language to CICS TS, without a dramatic change to the way CICS users thought of core concepts such as re-entrancy and isolation.

As enterprise usage of Java evolved, it began to make more and more use of multi-threaded environments where isolation was not a desired characteristic. Additionally, technologies such as OSGi (Open Service Gateway Initiative) evolved to overcome some of the original disadvantages of applying Java to an enterprise environment. As such, the limitations of the Pooled JVM approach began to outweigh the benefits.

In CICS TS V4.1 (2009), IBM introduced the new JVM server infrastructure in CICS TS as a replacement to the Pooled JVM approach. This JVM server infrastructure provides a much more standard Java environment that makes the writing and porting of Java applications for CICS TS much simpler.

In CICS TS V5.1 (2012), support for the old Pooled JVM infrastructure was removed. While there is a relatively simple migration path from Pooled JVM to JVM server, applications should no longer be written to the Pooled JVM infrastructure. There are a number of more recent IBM Redbooks® publications covering the replacement JVM server technology, including:

The remainder of this book discusses the old Pooled JVM technology at the CICS TS V3.2 (2007) level of capability. It is retained for historical purposes only.

This book was produced by a team of specialists from around the world working at Beijing, China.

Chris Rayns is an IT Specialist and Project Leader at the ITSO, Poughkeepsie Center in New York, where he specializes in security. Chris writes extensively on all areas of IBM S/390® security. Before joining the ITSO, he worked in IBM Global Services in the United Kingdom (UK) as a CICS IT Specialist.

George Burgess is currently working as the CICS Transaction Server on z/OS® Subject Matter Expert for the Peoples Republic of China and is based in Beijing. He has 24 years of experience as an Application Programmer, Systems Programmer, CICS Developer and OMEGAMON® XE for CICS Developer. His areas of expertise include Common Business Oriented Language (COBOL), CICS, DB2®, WebSphere® MQ, IMS™ DL/1, VSAM, JCL, z/OS, and OMEGAMON.

Scott Clee is the CICS Test Architect for IBM in the United Kingdom (UK). He frantically architects the face of Test by looking for new ways to push Testing techniques, process, and technology. He has a degree in Mathematics and Computing from the University of Bath, UK. His areas of expertise include CICS, Java, Common Business Oriented Language (COBOL), Linux, and Testing. Check out his blog at TestingBlues.com.

Tom Grieve Tom Grieve is a Software Engineer in CICS Development at Hursley Park, UK. He has a Bachelor of Science degree in Mathematics and Physics from the University of London and is currently studying for a Masters in Software Engineering at the University of Oxford. He has 35 years of experience as an Application Programmer, Systems Programmer, and Software Engineer. He has worked at IBM for the last five years in CICS and previously as a Developer on CICS for OS/2 and the Java Virtual Machine for OS/390®. His areas of expertise include CICS and Java.

John Taylor is a Software Engineer in CICS Development at Hursley Park, UK. He has a Bachelors degree in Digital Systems Engineering from the University of the West of England, Bristol and a Masters degree in Software Engineering from the University of Oxford. He has 12 years of experience as an Application Programmer, Tester, CICS Developer, and OMEGAMON XE for CICS Developer with IBM. His areas of expertise include CICS, Java, OMEGAMON, and various forms of tooling.

Yun Peng Ge is an Advisory IT Specialist in the Technical Sales Support team supporting mainframe WebSphere customers in China. He has a Bachelors degree in Computer Science from Fudan University in Shanghai. His areas of expertise includes CICS Transaction Server, WebSphere MQ, WebSphere Message Broker, J2EE, and z/OS.

Guo Qiang Li is a Software Engineer with the China CICS Team, which is the first team in CDL working on CICS Transaction Server. He graduated from Tianjin University with a Masters degree and joined the China CICS Team in 2006. He focuses on CICS Dynamic LIBRARY management testing and CICS Web Service support testing. His experiences on CICS include CPSM and Web Services.

Qian Zhang is an Advisory IT Specialist with the IBM ATS team of China, since 2004. He has eight years of experience working for IT development and IT support. His expertise resides in mainframe system knowledge, which includes CICS TS, Java, z/OS, MVS™, and parallel Sysplex. He has domestic and international experience in proof of concept and performance benchmarking on System z®. Between 2005 and 2007, he worked as a System Programmer at the IBM China System Center. He is currently committed to supporting CICS TS performance projects in China.

Derek Wen is an IT Specialist in IBM Global Technology Services® in Taiwan. He has over 20 years of experience in the IBM mainframe field and over 15 years of experience with CICS. His areas of expertise include zOS, MVS, CICS, Assembler, COBOL, and Java with a focus on heritage application integration with CICS.

Thanks to the following people for their contributions to this project:

Andrew Bates, CICS Product Management
IBM Hursley

Arndt Eade, CICS Advocacy Program
IBM Hursley

Richard M Conway
International Technical Support Organization, Poughkeepsie Center

Paul Cooper, CICS TS for z/OS Development
IBM Hursley

Joe Winchester, Software Developer
IBM Hursley

Dennis Weiand, ATS
IBM Dallas

Thanks to the authors of the previous editions of this book.

Scott Clee

Ulrich Gehlert

Vasilis Karras

Debra Payne

Bill Plowman

Join us for a two- to six-week residency program! Help write a book dealing with specific products or solutions, while getting hands-on experience with leading-edge technologies. You will have the opportunity to team with IBM technical professionals, Business Partners, and Clients.

Your efforts will help increase product acceptance and customer satisfaction. As a bonus, you will develop a network of contacts in IBM development labs, and increase your productivity and marketability.

Find out more about the residency program, browse the residency index, and apply online at:

Your comments are important to us!

We want our books to be as helpful as possible. Send us your comments about this book or other IBM Redbooks in one of the following ways:

IBM Corporation, International Technical Support Organization
Dept. HYTD Mail Station P099
2455 South Road
Poughkeepsie, NY 12601-5400