IBM Front cover Parallel Sysplex Application Considerationsderations Introducing architecture mindset to leverage z/OS sysplex applications Designing applications to benefit from Parallel Sysplex DB2, DFSMStvs, CICS, IMS, WebSphere MQ applications Jordi Alastrué i Soler Mak Anders, Karl Bender Amardeep Bhattal, Paolo Bruni Andy Clifton, John Iczkovits Franck Injey, Pirooz Joodi Vasilis Karras, Andy Mitchelmore Robert Queen, Mark Rader Mayur Raja, Pete Siddall Jens Erik Wendelboe ibm.com/redbooks International Technical Support Organization Parallel Sysplex Application Considerations October 2004 SG24-6523-00 Note: Before using this information and the product it supports, read the information in “Notices” on page vii. First Edition (August 2004) This edition applies to IBM Parallel Sysplex technology used with operating systems z/OS (program number 5694-A01) or OS/390 (program number 5647-A01.) © Copyright International Business Machines Corporation 2004. All rights reserved. Note to U.S. Government Users Restricted Rights -- Use, duplication or disclosure restricted by GSA ADP Schedule Contract with IBM Corp. Contents Notices . vii Trademarks . viii Preface . ix The team that wrote this redbook. ix Become a published author . xi Comments welcome. xii Chapter 1. Introduction to Parallel Sysplex . 1 1.1 What is a sysplex? . 2 1.1.1 Why use a sysplex? . 3 1.2 Data sharing in a sysplex . 5 1.3 Parallel processing in a sysplex . 8 1.4 Managing work in a sysplex . 14 Chapter 2. Application design . 17 2.1 Applications in a sysplex . 18 2.2 Enabling for continuous availability . 19 2.2.1 Affinities . 21 2.2.2 Locking . 24 2.2.3 Batch window . 25 2.2.4 Single points of failure. 25 2.2.5 Performance . 26 2.3 Step-wise deployment/versioning . 27 2.4 Other considerations . 29 2.4.1 Granularity, modularity, and generally reused modules . 29 2.4.2 Fault tolerance . 30 2.4.3 Debugging and tracing . 30 2.4.4 Testing environment . 31 Chapter 3. DB2 application considerations . 33 3.1 Introduction to DB2 data sharing. 34 3.1.1 Advantages of data sharing . 34 3.1.2 How data sharing works . 38 3.2 Application considerations for developers. 40 3.2.1 Locking . 40 3.2.2 Lock avoidance . 41 3.2.3 Commit frequency. 45 3.2.4 Locking recommendations . 46 3.2.5 DB2 database design . 47 3.2.6 Batch considerations. 51 3.2.7 Managing commit frequency in batch . 52 3.2.8 Distributed access to a data sharing group. 53 3.2.9 Programming guidelines . 54 3.2.10 Additional DB2 considerations . 55 3.3 Application considerations for DB2 system administrators . 56 3.3.1 BIND options. 57 3.3.2 DDL options . 58 3.3.3 DB2 installation options . 59 © Copyright IBM Corp. 2004. All rights reserved. iii 3.3.4 Deadlock and time-out detection . 61 3.3.5 Backup and recovery . 62 3.4 Example application . 62 3.4.1 Batch processing . 63 3.4.2 Parallelizing sequential processes . 64 3.4.3 Extraordinary processes . 65 Chapter 4. DFSMStvs application considerations . 67 4.1 Introduction to DFSMStvs . 68 4.2 Batch application considerations. 69 4.2.1 Unit of recovery. 69 4.2.2 Sharing files in the batch job structure . 70 4.3 Transactional recovery . 71 4.3.1 Using DFSMStvs: unique input . 73 4.3.2 Using DFSMStvs: shared input. 75 4.4 Programming changes . 77 Chapter 5. CICS application considerations. 81 5.1 Introduction to CICS TS . 82 5.2 How to exploit sysplex in CICS TS applications . 82 5.2.1 Affinities through use of CICS commands . 85 5.2.2 CICS Transaction Affinities Utility . 87 5.2.3 Programing facilities and techniques and their implications on affinities . 89 5.2.4 Affinity summary . 92 5.2.5 What happens if you have to create an affinity? . 92 5.3 CICS TS application checklist . 92 Chapter 6. IMS application considerations. 95 6.1 IMS Transaction Manager overview . ..