UNIVERSITY OF LEIPZIG Department of Computer Science Generation of a Java front end for a standalone CICS application accessed through MQSeries & Securing CICS with RACF Diplomarbeit – Master Thesis Submitted by Tobias Busse 1st Examiner: Prof. Dr.-Ing. W. G. Spruth Born: 1976/07/14 2nd Examiner: Peter Missen Subject: Computer Science Matr.Nr.: 7952583 Leipzig, August 2004 EXECUTIVE SUMMARY This master thesis deals with the design, programming, implementation and presentation of on-line business ap- plications for IBM's On-Line Transaction Processing (OLTP) system called Customer Information Control Sys- tem (CICS). According to the book “Designing and Programming CICS Applications” published by John Hor- swill [HOR00] we explain two out of many feasible procedures to present the functionality of CICS resp. CICS business applications. As the main result, we create for each of both procedures a business application representing a little clip of a bank customer account program. These applications access a database-like file stored on an Operating System/390 (OS/390) server to create, read, update, and delete customer accounts. Both use CICS not only as a transaction processing system but also as an application server that manages business applications 24 hours a day for 7 days a week. The difference between the two business applications are the data transfer and information dis- play methods. The first procedure describes how to create a business application that uses the legacy 3270 inter- face to inquire a customer record stored on the OS/390-server and how to display the information on a 3270 ter- minal screen (also called as the green screen). In contrast, the second business application uses message queuing provided by IBM's Message Oriented Middleware (MOM) product MQSeries to transfer the request data to and the response data from the customer account file between CICS and the Java Virtual Machine (JVM). This JVM runs on a WINDOWS2000 client, whereas MQSeries has to run on both – the OS/390-server and the WIN- DOWS2000 client. For this procedure, the so-called MQSeries CICS Bridge – an interface between CICS and MQSeries on the OS/390-server – is installed and activated. It is also described how to use the Message Queue Interface (MQI) that connects MQSeries and JAVA on the client computer system. Hence, the business logic component is used by both sample applications, but they differ in the presentation logic components. The programs of the business logic component, written in the programming language CO- BOL, are responsible for the data transfer to and from the customer account file to update or read it, for the busi- ness calculations, and for the error handling. The presentation logic component of the first business application – the CICS application NACT – is also written in COBOL and use the Basic Mapping Support (BMS) to set up the 3270 interface. In the second business application called the MQSeries CICS application MQNACT the pro- grams of the presentation logic component are written in JAVA. Additionally, this master thesis describes the security management of CICS using IBM's External Security Manager (ESM) Resource Access Control Facility (RACF). The main part of this procedure is to allow only au- thorised terminal users an access to an existing CICS address space, including some CICS default user IDs as for example the CICS Region User ID (CRU), and the Default CICS User ID (DCU). Furthermore, the authorised user should/may use only those CICS resources for which a permission exists. Securing CICS resources is ex- plained on the examples of the CICS Transactions Security mechanism and the CICS Command Security mech- anism. “There is no human on the world from whom you cannot learn something.” (Albert Schweitzer) Acknowledgements My thanks goes to Prof. Dr. Wilhelm G. Spruth who gave me the best support and who never despaired on my English writing. I wish to thank Peter Missen, head of the CICS User Group at IBM Hursley UK, for helping, for redacting this text, and, of course, for working with the CICS User Group. My technical thanks goes to Dr. Paul Herrmann who always sustained the functionality of the JEDI OS/390-server. Many thanks goes also to: Nils Michaelsen for his encouragement in my work, Ulrike Kirsch (IBM Leipzig Germany) for her support on MQSeries, Sandro Varges (IBM Mainz Germany) for his support on CICS (“Haeh, What is a CSD, Sandro?” ), Thomas Renner (IBM Leipzig Germany) for his support on RACF and JCL, Ingo Karge who provided for me a desk at the IBM Leipzig location, the CICS User Group, especially to Paul …, James Taylor, and Kevin ..., and to everyone at IBM Leipzig. I would also like to thank my family for their constant support. For my lovely butterfly Ivonne Lange, the sun should always shine. Thanks for your support, for your lovely cooking, for your understanding in my work and for your +encouragement. Together we will fight the future! TABLE OF CONTENTS List of Figures ................................................................................................... xi List of Tables .................................................................................................... xv List of Listings .................................................................................................. xvii List of Abbreviations ........................................................................................ xix Notices .............................................................................................................. xxi 1 Introduction to OS/390 23 1.1 Introduction .................................................................................................................... 23 1.2 History of OS/390 ........................................................................................................... 24 1.3 OS/390 in general .......................................................................................................... 27 1.4 OS/390 V2R7 ................................................................................................................. 30 2 Introduction to CICS 33 2.1 Introduction .................................................................................................................... 33 2.2 History of CICS .............................................................................................................. 34 2.3 CICS in general .............................................................................................................. 36 3 The Initial Architecture of the CICS Business Applications 39 4 The CICS Business Application NACT 41 4.1 Introduction .................................................................................................................... 41 4.2 Uploading the files ......................................................................................................... 42 4.3 The NACT COBOL programs and their commands ...................................................... 49 4.3.1 Overview .................................................................................................................. 49 4.3.2 The presentation logic component ........................................................................... 49 4.3.3 The business logic component ................................................................................ 54 4.3.4 Other commands that control the programs ............................................................ 56 4.3.5 Excursion: Storing exchange data – When to use the COMMAREA? ..................... 57 4.3.5.1 Overview ............................................................................................................ 57 4.3.5.2 Temporary Storage – queuing and scratchpad facility ...................................... 59 4.3.5.3 Transient Data – queuing facility ........................................................................ 60 4.3.5.4 COMMAREA – a scratchpad facility .................................................................. 60 4.3.5.5 Common Work Area, Transaction Work Area, and Terminal User Area – other Generation of a Java front end for a standalone CICS application accessed through MQSeries & viii Securing CICS with RACF scratchpad facilities .......................................................................................................... 67 4.4 Storing the data – account file, locking file, and name file ............................................. 68 4.4.1 File description ......................................................................................................... 68 4.4.2 Installing the storing data ......................................................................................... 70 4.5 The CICS resource definitions ....................................................................................... 74 4.5.1 Overview .................................................................................................................. 74 4.5.2 Setting up the CICS resources ................................................................................. 74 5 The MQSeries CICS Business Application MQNACT 81 5.1 Introduction .................................................................................................................... 81 5.2 Messaging and Queuing ................................................................................................ 83 5.2.1 Overview .................................................................................................................