IBM IMS, ESA V6 User Manual

0 (0)

IBM

IMS/ESA V6

Parallel Sysplex Migration Planning Guide for IMS TM and DBCTL

Bob Gendry, Bill Keene, Rich Lewis, Bill Stillwell, Scott Chen

International Technical Support Organization

http://www.redbooks.ibm.com

SG24-5461-00

IBM	International Technical Support Organization	SG24-5461-00

IMS/ESA V6

Parallel Sysplex Migration Planning Guide for IMS TM and DBCTL

June 1999

Take Note!

Before using this information and the product it supports, be sure to read the general information in Appendix F, “Special Notices” on page 239.

First Edition (June 1999)

This edition applies to Version 6, Release Number 1 of IMS/ESA, Program Number 5655-158 for use with the

MVS/ESA or OS/390 operating system.

Comments may be addressed to:

IBM Corporation, International Technical Support Organization Dept. QXXE Building 80-E2

650 Harry Road

San Jose, California 95120-6099

When you send information to IBM, you grant IBM a non-exclusive right to use or distribute the information in any way it believes appropriate without incurring any obligation to you.

Note to U.S. Government Users — Documentation related to restricted rights — Use, duplication or disclosure is subject to restrictions set forth in GSA ADP Schedule Contract with IBM Corp.


Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .			xi
Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .			xiii
Preface	. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		xv
The Team That Wrote This Redbook . . . . . . . . . . . . . . . . . . . . . . . . .			xv
Comments Welcome		. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	xvi
Chapter 1.	Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		1

1.1Purpose of This Redbook . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

1.2Organization of This Redbook . . . . . . . . . . . . . . . . . . . . . . . . . . 1

1.3Prerequisite Knowledge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1.4Assumptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Part 1. Developing the Plan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Chapter 2. Plan Development . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

2.1Planning for Migration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

2.1.1Planning Phase . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

2.1.2Preparation Phase . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

2.1.3Implementation Phase . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Part 2. Planning Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	11
Chapter 3. Planning Considerations with IMS/ESA V6 in Mind . . . . . . . . .	13
3.1 Discussing the Use of Traditional Queuing and Shared Queues . . . . . .	17
Chapter 4. Planning Configurations After Failures . . . . . . . . . . . . . . . . .	19
4.1 IRLMs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	19
4.1.1 Restarting Batch (DLI and DBB) Data-Sharing Jobs . . . . . . . . . .	21

4.2IMS Subsystem Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . 22

4.3IMS Data-Sharing Subsystems . . . . . . . . . . . . . . . . . . . . . . . . . . 22

4.4 IMS Subsystems Utilizing Shared Queues . . . . . . . . . . . . . . . . . . . 23

4.5IMS Subsystems Utilizing VTAM Generic Resources . . . . . . . . . . . . . 24

4.6FDBR Action After an IMS Failure . . . . . . . . . . . . . . . . . . . . . . . . 25

4.7Restarting BMPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

4.8Degraded Mode Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Chapter 5. System Environment Consideration . . . . . . . . . . . . . . . . . . 27

5.1Naming Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

5.2IMS Subsystem Data Sets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

5.2.1IMS Data Sets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

5.2.2CQS Data Sets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

5.2.3Data Set Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

5.3Executable Code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

5.3.1IMS System Code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

5.3.2CQS System Code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

5.3.3Exit Code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

5.3.4Application Program Code . . . . . . . . . . . . . . . . . . . . . . . . . . 32

5.4Control Blocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

iii

5.4.1CQS Access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

5.4.2Online Access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

5.5Parameter Libraries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

5.6Dynamic Allocation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

5.7JCL Libraries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

5.7.1Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

5.7.2Jobs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

5.7.3DBRC JCL Libraries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

5.8Making the Decision . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

5.8.1Data Sets That Must Be Unique . . . . . . . . . . . . . . . . . . . . . . 37

5.8.2Data Sets That Must Be Shared . . . . . . . . . . . . . . . . . . . . . . 38

5.8.3	Data Sets That Are Probably Shared	. . . . . . . . . . . . . . . . . . .	38
5.8.4	Data Sets That Are Probably Unique	. . . . . . . . . . . . . . . . . . .	40
Chapter 6. Applications and Databases . .		. . . . . . . . . . . . . . . . . . . . .	41

6.1Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

6.2Databases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

6.3	Partitioned Applications and Databases	. . . . . . . . . . . . . . . . . . . .	42
6.4	Cloned Applications and Data Sets . . .	. . . . . . . . . . . . . . . . . . . .	42
6.5	Handling Databases That Are Not Shared	. . . . . . . . . . . . . . . . . . .	42

6.5.1Routing Transactions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

6.5.2Copying Databases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

Part 3. Planning Considerations for IMS TM . . . . . . . . . .		. . . . . . . . . . . . . . . . .	45
Chapter 7. Introduction to IMS TM Considerations		. . . . . . . . . . . . . . . .	47
7.1	Overview . . . . . . . . . . . . . . . . . . . . . .	. . . . . . . . . . . . . . . . .	47
7.2	IMS TM Configuration Considerations . . . .	. . . . . . . . . . . . . . . . .	48

7.2.1Cloning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

7.2.2Joining . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

7.2.3Front-End and Back-End . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

Chapter 8. IMS TM Network Considerations . . . . . . . . . . . . . . . . . . . . 53

8.1Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

8.2Special Network Considerations . . . . . . . . . . . . . . . . . . . . . . . . . 54

8.2.1SLUTYPEP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

8.2.2 ISC . . . . . . . . . . . . . . . . . . .		. . . . . . . . . . . . . . . . . . . . .	55
8.3	APPC (LU 6.2) . . . . . . . . . . . . . . .	. . . . . . . . . . . . . . . . . . . . .	58
8.4	ETO Considerations with Shared Queues	. . . . . . . . . . . . . . . . . . .	59

8.4.1Duplicate Terminal Names . . . . . . . . . . . . . . . . . . . . . . . . . 59

8.4.2Solutions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60


8.4.3		Limiting the Number of End-User Signons . . . . . . . . . . . . . . . .	61
8.4.4		Dead Letter Queue Considerations . . . . . . . . . . . . . . . . . . . .	61
8.5	Conversational Transaction Processing . . . . . . . . . . . . . . . . . . . .		62
8.6	Application Program Considerations . . . . . . . . . . . . . . . . . . . . . .		62

8.7Application Affinities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

8.8IMS APPLIDs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

8.9	VTAM Model Application Program Definitions . . .	. . . . . . . . . . . . . .	64
8.10	A Model Application Program Definition Example	. . . . . . . . . . . . . .	64
Chapter 9. IMS TM Workload Balancing Considerations		. . . . . . . . . . . . .	65

9.1Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

9.2Network Workload Balancing . . . . . . . . . . . . . . . . . . . . . . . . . . . 66

9.2.1Instructions to the End-Users . . . . . . . . . . . . . . . . . . . . . . . . 67

ivIMS Parallel Sysplex Migration Planning Guide

9.2.2	USSTAB Processing . . . . . . . . . . . .	. . . . . . . . . . . . . . . . .	67
9.2.3	CLSDST PASS VTAM Application Program	. . . . . . . . . . . . . . . .	67

9.2.4USERVAR Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

9.2.5Use of VTAM Generic Resources . . . . . . . . . . . . . . . . . . . . . . 69

9.2.6	VTAM Generic Resources for APPC/IMS . . . . . . .	. . . . . . . . . .	72
9.2.7	Printers and Network Workload Balancing . . . . . .	. . . . . . . . . .	73
9.2.8	Network Workload Balancing With Session Managers	. . . . . . . . .	76
9.2.9	Network Workload Balancing With TCP/IP and TN3270	. . . . . . . . .	79

9.3Application Workload Balancing . . . . . . . . . . . . . . . . . . . . . . . . . 81

9.3.1Network Workload Balancing . . . . . . . . . . . . . . . . . . . . . . . . 81

9.3.2MSC Balancing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82

9.3.3IMS Workload Router . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82


9.3.4 Shared Queues and Application Workload Balancing		. . . . . . . . .	83
9.4	Transaction Scheduling Considerations . . . . . . . . . . . . . . . . . . . .		85
9.5	Summary of Workload Balancing Considerations . . . . . . . . . . . . . . .		85
Chapter 10. IMS TM System Definition Considerations . . . . . . . . . . . . . .			87
10.1	Master Terminals With IMS/ESA Version 5 . . . . . . . . . . . . . . . . . .		87
10.2	Master Terminals With IMS/ESA Version 6 . . . . . . . . . . . . . . . . . .		88

10.3Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89

10.4Resource Definitions and Usage . . . . . . . . . . . . . . . . . . . . . . . . 89

10.5MSC Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90

10.5.1	Inter-IMSplex MSC Without Shared Queues . . . . .	. . . . . . . . . .	90
10.5.2	Migration to Shared Queues . . . . . . . . . . . . . .	. . . . . . . . . .	91
10.5.3	Example: Migration of Two MSC-Connected Systems	. . . . . . . .	95

10.5.4Example: MSC Link from a Shared Queues Group Member to a Remote IMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97

10.5.5Example: MSC Link Between Members of Two Shared Queues

Groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		.	99
10.5.6	Example: Multiple MSC Links between Members of Two Shared
Queues Groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		.	99
10.5.7	Example: Backup MSC Link Configuration . . . . . . . . . . . . . .		100
10.6 Serial Transactions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .			102
10.6.1	Serial Transactions With Traditional Queuing . . . . . . . . . . . . .		102
10.6.2	Serial Transactions With Shared Queues . . . . . . . . . . . . . . .		102

10.7Undefined Destinations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103

10.7.1Destination Determination . . . . . . . . . . . . . . . . . . . . . . . . 104

10.7.2	Back-End Processing of Input Transactions . . . . . . . . . . . . . .	104
10.7.3	Comments and Recommendations . . . . . . . . . . . . . . . . . . .	104

10.8Online Change . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105

10.9SPOOL Terminals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105

Part 4. Data-Sharing and Shared Queues Considerations . . . . . . . . . . . . . . . . . .	107
Chapter 11. Data-Sharing Enablement . . . . . . . . . . . . . . . . . . . . . . .	109

11.1IMS System Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109

11.2IRLM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110

11.2.1IRLM Subsystem Names . . . . . . . . . . . . . . . . . . . . . . . . . 110

11.2.2IRLM as Lock Manager . . . . . . . . . . . . . . . . . . . . . . . . . . 110

11.2.3IRLM Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111

11.3DBRC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111

11.3.1SHARECTL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111

11.3.2SHARELVL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111

11.3.3Skeletal JCL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112

Contents v

15.1 Coupling Facility Planning Guidelines

11.4Database Data Set Sharability . . . . . . . . . . . . . . . . . . . . . . . . 112

11.4.1VSAM SHAREOPTION(3 3) . . . . . . . . . . . . . . . . . . . . . . . . 112

11.4.2DISP=SHR in JCL or DFSMDA . . . . . . . . . . . . . . . . . . . . . 112

11.5CFNAMES Statement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113

11.6 DEDB Statements in the DFSVSMxx Member . . . . . . . . . . . . . . . 113

11.7Order of Implementation Steps . . . . . . . . . . . . . . . . . . . . . . . . 114

11.8IMS Procedures for Data-Sharing . . . . . . . . . . . . . . . . . . . . . . 116

11.9	Data-Sharing Performance Considerations . . . . . . . . . . . . . . . . .	118
11.10	Sources of Performance Information . . . . . . . . . . . . . . . . . . . .	120
11.11	Data Sharing Coupling Facility Performance Impacts . . . . . . . . . .	121

11.11.1IRLM CF Access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122

11.11.2IMS CF Access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123

Chapter 12. Shared Queues Enablement . . . . . . . . . . . . . . . . . . . . . 125

12.1Program Properties Table . . . . . . . . . . . . . . . . . . . . . . . . . . . 125

12.2Structure Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125

12.3Log Stream Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125

12.4System Checkpoint Data Sets . . . . . . . . . . . . . . . . . . . . . . . . . 125

12.5Structure Recovery Data Sets . . . . . . . . . . . . . . . . . . . . . . . . . 126

12.6CQS Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126

12.7 BPE Configuration PROCLIB Member . . . . . . . . . . . . . . . . . . . . 126

12.8CQS Initialization Parameters PROCLIB Member (CQSIPxxx) . . . . . . 126

12.9CQS Local Structure Definition PROCLIB Member (CQSSLxxx) . . . . . 126

12.10 CQS Global Structure Definition PROCLIB Member (CQSSGxxx) . . . 126

12.11Security for CQS Structures . . . . . . . . . . . . . . . . . . . . . . . . . 127

12.12ARM Policy Updates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127

12.13 IMS Shared Queues PROCLIB Member (DFSSQxxx) . . . . . . . . . . 127

12.14QMGR and Shared Queues Traces . . . . . . . . . . . . . . . . . . . . . 127

12.15IMS Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127

12.16 IMS Procedures for Shared Queues . . . . . . . . . . . . . . . . . . . . 127

Part 5. MVS Parallel Sysplex Conderations . . . . . . . . . . . .	. . . . . . . . . . . . . . . .	129
Chapter 13. VTAM Generic Resources Enablement	. . . . . . . . . . . . . . .	131

13.1VTAM Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131

13.2IMS Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131

13.3APPC/IMS Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . 131

Chapter 14. Automatic Restart Manager (ARM)

14.1 Exceptions to Automated Restarts of IMS

. . . . . . . . . . . . . . . . .	133
. . . . . . . . . . . . . . . . . .	133

14.2Restart Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134

14.3Restart Groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134

14.4Other ARM Capabilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135

14.5ARM with IRLM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136

14.5.1Restarting after IRLM Abends . . . . . . . . . . . . . . . . . . . . . . 136

14.5.2Restarting after System Failures . . . . . . . . . . . . . . . . . . . . 136

14.6ARM with CQS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136

14.7ARM with FDBR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137

14.8Information for ARM Policies . . . . . . . . . . . . . . . . . . . . . . . . . 137

Chapter 15. Coupling Facility . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139

. . . . . . . . . . . . . . . . . . . . 139

15.1.1Structure Placement Rules . . . . . . . . . . . . . . . . . . . . . . . . 139

15.1.2Initial Structure Placement . . . . . . . . . . . . . . . . . . . . . . . . 140

viIMS Parallel Sysplex Migration Planning Guide

15.1.3Structure Sizing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141

15.1.4IMS Database Manager . . . . . . . . . . . . . . . . . . . . . . . . . . 141

15.1.5IRLM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146

15.1.6Shared Queues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148

15.1.7	Summary of Structure Characteristics . . . . . . . . . . . . . . . . .	150
15.2 Changing CF Structure Sizes . . . . . . . . . . . . . . . . . . . . . . . . .		151
15.2.1	Connection and Structure Persistence . . . . . . . . . . . . . . . . .	151
15.2.2	IMS Buffer Invalidation Structure Changes . . . . . . . . . . . . . .	151
15.2.3	DEDB VSO Cache Structure Changes . . . . . . . . . . . . . . . . .	152

15.2.4IRLM Lock Structure Changes . . . . . . . . . . . . . . . . . . . . . . 152

15.2.5Automatic Rebuilds . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153

15.2.6	Shared Queues Structure Changes . . . . . . . . . . . . . . . . . . .	154
15.2.7	Alter and Rebuild for Shared Queues Structures . . . . . . . . . . .	154

Part 6. Operation Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157

Chapter 16. IMS Connections, Security and User Exits . . . . . . . . . . . . . 159

16.1IMS Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159

16.2Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160

16.2.1RACF Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160

16.3IMS SMU Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161

16.4Database Data Set Dispositions . . . . . . . . . . . . . . . . . . . . . . . 161

16.5User Exits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162

16.5.1IMS System Exits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162

16.5.2IMS Database Manager Exits . . . . . . . . . . . . . . . . . . . . . . 163

16.5.3IMS Transaction Manager Exits . . . . . . . . . . . . . . . . . . . . . 163

16.5.4 Common Queue Server Exit Routines . . . . . . . . . . . . . . . . .	164
Chapter 17. IMS and User JCL . . . . . . . . . . . . . . . . . . . . . . . . . . .	167

17.1IMS Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167

17.1.1Started Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167

17.1.2Executed Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . 170

17.2IMS Jobs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170

17.3DBRC Skeletal JCL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172

17.4Other Backup and Recovery JCL . . . . . . . . . . . . . . . . . . . . . . . 173

17.5Other Application JCL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173

17.6BMP JCL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173

17.6.1	Using the Function Delivered by APAR PQ21039	. . . . . . . . . . .	173
17.6.2	The IMSGROUP Function . . . . . . . . . . . . . .	. . . . . . . . . . .	174
17.6.3	Handling IMSID Without APAR PQ21039 Function	. . . . . . . . . .	174

17.6.4Maintenance Levels of RESLIB . . . . . . . . . . . . . . . . . . . . . 177

17.6.5Routing BMP Jobs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177

Chapter 18. Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179

18.1Operational Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179

18.2Automated Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179

18.2.1IMS Time-Control Operations . . . . . . . . . . . . . . . . . . . . . . 179

18.2.2IMS AO Exits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180

18.2.3Other AO Products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180

18.3Use of IRLM SCOPE=NODISCON . . . . . . . . . . . . . . . . . . . . . . 180

18.3.1Use of RDI Regions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181

18.4Recovery Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182

18.5Support Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182

18.6IMS Log Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183

Contents vii

18.6.1IMS Log Archive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183

18.7Job Scheduling Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . 183

18.8Online Change Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . 184

18.9 IMS Commands from MVS Consoles . . . . . . . . . . . . . . . . . . . .		184
18.9.1	GLOBAL Commands . . . . . . . . . . . . . . . . . . . . . . . . . . .	185
18.9.2	Alternative to GLOBAL Commands . . . . . . . . . . . . . . . . . . .	187
18.9.3	Recommendations for IMS Commands From MVS Consoles . . .	187
Chapter 19. Fast Database Recovery (FDBR) . . . . . . . . . . . . . . . . . . .		189

19.1FDBR Monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189

19.1.1Log Monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189

19.1.2XCF Status Monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . 190

19.2Invoking Recovery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191

19.3FDBR Failures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192

19.4 Restarting IMS after FDBR Completion . . . . . . . . . . . . . . . . . . . 192

19.5DBRC Authorizations with FDBR . . . . . . . . . . . . . . . . . . . . . . . 192

19.6ARM and FDBR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192

19.6.1 ARM Support for IMS With FDBR Active . . . . . . . . . . . . . . . . 192

19.6.2ARM Support for FDBR . . . . . . . . . . . . . . . . . . . . . . . . . . 193

19.7FDBR, XRF, and ARM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193

19.7.1	FDBR Advantages and Disadvantages . . . . . . . . . . . . . . . . .	193
19.7.2	XRF Advantages and Disadvantages . . . . . . . . . . . . . . . . . .	194
19.7.3	ARM Advantages and Disadvantages . . . . . . . . . . . . . . . . .	194
19.8 Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		194
Chapter 20. Recovery Procedures . . . . . . . . . . . . . . . . . . . . . . . . .		197
20.1 Image Copies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		197
20.1.1	Database Image Copy (DFSUDMP0) . . . . . . . . . . . . . . . . . .	197
20.1.2	Concurrent Image Copy (DFSUDMP0 with CIC Option) . . . . . . .	197
20.1.3	Online Database Image Copy (DFSUICP0) . . . . . . . . . . . . . . .	197
20.1.4	Database Image Copy 2 (DFSUDMT0) . . . . . . . . . . . . . . . . .	198

20.1.5Summary of Image Copies . . . . . . . . . . . . . . . . . . . . . . . . 198

20.2Database Recoveries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198

20.2.1 Time-Stamp Recovery Considerations . . . . . . . . . . . . . . . . .	199
20.3 IMS Batch (DBB and DLI) Job Abends . . . . . . . . . . . . . . . . . . .	200

20.4IMS Online (TM or DBCTL) Abends . . . . . . . . . . . . . . . . . . . . . 200

20.5IRLM Abends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200

20.6MVS Failures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200

20.7Lock Structure Failures . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201

20.8OSAM and VSAM Structure Failures . . . . . . . . . . . . . . . . . . . . . 202

20.9DEDB VSO Structure Failures . . . . . . . . . . . . . . . . . . . . . . . . . 202


20.9.1		Procedure for Failure of One of Two Structures . . . . . . . . . . .				203
20.9.2		Procedure for Failure of Only Structure or Both Structures			. . . .	203
20.10	CF Connection Failures . . . . . . . . . . . . . . . . . . . . . . . . . . . .					203
20.11	CF Connection Failure to Lock Structure		. . . . . . . . . . . . . . . . .			203
20.12	CF Connection Failure to an OSAM or VSAM Structure . . . . . . . . .					204
20.13	CF Connection Failure to a DEDB VSO Structure			. . . . . . . . . . . .		204
20.13.1		Procedure with Connectivity to a Second Structure . . . . . . . .				205
20.13.2		Procedure without Connectivity to a Second Structure			. . . . . .	205
20.14	Disaster Recovery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .					205
20.14.1		Image Copy Only Disaster Recovery . . . . . . . . . . . . . . . . .				205
20.14.2		Time-Stamp Recovery Disaster Recovery . . . . . . . . . . . . . .				206
20.14.3		Latest Archived Log Disaster Recovery	. . . . . . . . . . . . . . .			206
20.14.4		Real-Time Electronic Log Vaulting Disaster Recovery . . . . . . .				207

viii IMS Parallel Sysplex Migration Planning Guide


Appendix A. Naming Convention Suggestions . . . . . . . . . . . . . . . . . .			209
Appendix B. IMS System Data Sets . . . . . . . . . . . . . . . . . . . . . . . .			215
B.1	Data Sets That Must Be Unique . . . . . . . . . . . . . . . . . . . . . . . .		215
B.2	Data Sets That Must Be Shared . . . . . . . . . . . . . . . . . . . . . . . .		216
B.3	Data Sets That Are Probably Unique . . . . . . . . . . . . . . . . . . . . .		216
B.4	Data Sets That Are Probably Shared . . . . . . . . . . . . . . . . . . . . .		216
Appendix C. Sample USERVAR Exit for Network Balancing . . . . . . . . . .			219
Appendix D. Parallel Sysplex Publications . . . . . . . . . . . . . . . . . . . .			231
Appendix E. Migration Plan Task List . . . . . . . . . . . . . . . . . . . . . . .			233
E.1	Planning Phase . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		234
E.2	Preparation Phase . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		235
E.3	Implementation Phase . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		237
E.3.1		Data Sharing Environment Implementation . . . . . . . . . . . . . . .	237
E.3.2		Generic Resources Environment Implementation . . . . . . . . . . .	237
E.3.3		Shared Queues Environment Implementation . . . . . . . . . . . . .	238
E.3.4		Implementation of Second System (Clone) . . . . . . . . . . . . . . .	238
Appendix F. Special Notices . . . . . . . . . . . . . . . . . . . . . . . . . . . .			239
Appendix G. Related Publications . . . . . . . . . . . . . . . . . . . . . . . . .			241
G.1	International Technical Support Organization Publications . . . . . . . .		241
G.2	Redbooks on CD-ROMs . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		241
G.3	Other Publications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		241
How to Get ITSO Redbooks . . . . . . . . . . . . . . . . . . . . . . . . . . . . .			243
IBM Redbook Fax Order Form . . . . . . . . . . . . . . . . . . . . . . . . . . . .			244
Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .			245
List of Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .			249
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .			251
ITSO Redbook Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .			253

Contents ix

x IMS Parallel Sysplex Migration Planning Guide

Figures

1.	Using Unique IRLM Names and Moving IRLMs . . . . . . . . .	. . . . . .	20
2.	Using Unique IRLM Names and Changing IRLMs Used by IMSs	. . . . .	21

3.Using ″IRLM″ for all IRLM Names . . . . . . . . . . . . . . . . . . . . . . . 21

4.	Using One Instance of a Session Manager Without ISTEXCGR . . . . . .	77
5.	Using One Instance of a Session Manager With ISTEXCGR . . . . . . . .	77
6.	Placing the Session Manager on an MVS Without IMS . . . . . . . . . . .	78
7.	Session Managers With Generic Resource Support . . . . . . . . . . . .	78
8.	Using DNS With TN3270 and VTAM GR . . . . . . . . . . . . . . . . . . . .	79
9.	Using DNS With TN3270 and VTAM GR . . . . . . . . . . . . . . . . . . . .	80

10.Using DNS With TN3270 and VTAM GR After a Failure of IMS1 . . . . . . 81

11.	Two IMS systems With an MSC connection . . . . . . . . . . . . . .	. . .	95
12.	Migration of IMSB to a Shared Queues Group . . . . . . . . . . . . .	. . .	96
13.	Migration of IMSA and IMSB to a shared queues group is completed	.	96

14.MSC link from shared queues group member to remote IMS . . . . . . . 98

15.	MSC links between members of two shared queues groups . . . . . .	. 99
16.	MSC connections from shared queues group members to remote IMS
	systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	100
17.	Backing up logical links from a shared queues group to a remote IMS	101
18.	Starting a backup link to a shared queues group . . . . . . . . . . . . .	101

xii IMS Parallel Sysplex Migration Planning Guide

Tables

1.IMS Online Region Library . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

2.IMS Procedures Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . 116

3. IMS Shared Queues Procedure Parameters . . . . . . . . . . . . . . . . 128

4.ARM Element Terms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137

5.Structure Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . 150

6.Summary of IMS Connectors . . . . . . . . . . . . . . . . . . . . . . . . . 159

7.IMSID Usage Before Cloning . . . . . . . . . . . . . . . . . . . . . . . . . 174

8.IMSID Usage After Cloning . . . . . . . . . . . . . . . . . . . . . . . . . . 174

9. Image Copy With Concurrent Updates . . . . . . . . . . . . . . . . . . . 198

10.Task List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 234

11.Task List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 235

12.Task List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237

13.Task List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237

14.Task List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 238

15.Task List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 238

xiii

xiv IMS Parallel Sysplex Migration Planning Guide

Preface

This redbook provides information for those planning for migrating IMS/ESA 6.1 system to a Parallel Sysplex environment using data sharing and shared queues.

The redbook lists all important factors to be consider during the planning stage. It also lists important features and describes the relationships between IMS/ESA V6 and OS/390. Readers will, therefore, be able to understand what benefits can be derived even before the complete implementation to the Parallel Sysplex environment.

The target audience is customer IT architects, system designers, IT managers and IBM representatives who are helping customers on migration projects.

The Team That Wrote This Redbook

This redbook was written by a team of IMS specialists from the IMS Advanced Technical Support Department at the IBM Dallas Systems Center.

Bob Gendry has been a member of the IMS Advanced Technical Support Department at the IBM Dallas Systems Center since 1978 and has over 25 years of experience in providing technical support for IMS. He has given multiple presentations on IMS-related topics to user groups and at the IMS Technical Conferences in the United States and Europe. He has provided assistance to multiple IMS users in planning and implementating IMS in a Parallel Sysplex environment for the past several years. In addition, he has prepared and taught educational materials directly related to the understanding, implementation, and use of IMS in a Parallel Sysplex environment.

Bill Keene was a member of the IMS Advanced Technical Support team at the IBM Dallas Systems Center. He has over 25 years of experience in providing technical support for IMS. He is a frequent speaker at GUIDE, SHARE, and IMS Technical Conferences on IMS-related topics. He has provided assistance to multiple IMS users in planning for and implementing the use of IMS in a Parallel Sysplex environment for the past several years. In addition, he has prepared and taught educational materials directly related to the understanding, implementation, and use of IMS in a Parallel Sysplex environment.

After contributing to this redbook, Bill Keene retired from IBM.

Rich Lewis has been a member of the IMS Advanced Technical Support Department at the IBM Dallas Systems Center since 1979. He has over 25 years of experience in providing technical support for IMS. Since the introduction of Parallel Sysplex, he has been assisting users in implementing IMS data-sharing. He has written technical documents, created presentations, and developed an IMS Parallel Sysplex data sharing course. He has provided planning services to many customers for the introduction of IMS into their Parallel Sysplex environments. Rich regularly presents Parallel Sysplex topics at IMS Technical Conferences and user group meetings in the United States and Europe.

Bill Stillwell has been providing technical support and consulting services to IMS customers as a member of the Dallas Systems Center for 17 years. During that time, he developed expertise in application and database design, IMS

performance, fast path, data sharing, planning for IMS Parallel Sysplex exploitation and migration, DBRC, and database control (DBCTL).

He also develops and teaches IBM Education and Training courses, including IMS/ESA Version 6 Product Enhancements, IMS Shared Queues, and IMS Fast Path Implementation, and is a regular speaker at the annual IMS Technical Conferences in the United States and Europe.

Scott Chen is a member of International Technical Support Organization, San Jose Center. Scott has installing, configuring, debugging, tuning, consulting, application designing, programming and studying MVS and OS/390 internal, database and transaction management system (includes IMS) and digital library softwares for over 25 years.

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

Dick Hannan

IBM Santa Teresa Laboratory

IMS Development

Comments Welcome

Your comments are important to us!

We want our redbooks to be as helpful as possible. Please send us your comments about this or other redbooks in one of the following ways:

•Fax the evaluation form found in “ITSO Redbook Evaluation” on page 253 to the fax number shown on the form.

•Use the online evaluation form found at http://www.redbooks.ibm.com/

•Send your comments in an Internet note to redbook@us.ibm.com

xvi IMS Parallel Sysplex Migration Planning Guide

Chapter 1. Introduction

1.1 Purpose of This Redbook

This redbook provides information for those creating a plan for migrating an IMS/ESA 6.1 system to a Parallel Sysplex environment using data sharing and shared queues. The reader is assumed to be familiar with the requirements for data sharing and shared queues implementation. This information may be obtained from the IBM Education and Training classes for IMS/ESA Block Level Data Sharing, Shared Queues, and IMS/ESA Version 6 and from IMS/ESA Data Sharing in a Parallel Sysplex, SG24-4303.

The redbook applies to both IMS/ESA TM and Database Control (DBCTL) users. Some Parallel Sysplex functions and facilities, such as Shared queues, apply only to IMS Transaction Manager (TM) users. Sections of this redbook which apply only to IMS TM users or only to DBCTL users are identified.

1.2 Organization of This Redbook

The main body of this redbook is divided into six sections plus several appendices.

1. Developing the Plan

This section addresses the plan itself, including the purpose of the plan, its content, and the migration tasks that should be identified within the plan.

2. Planning Considerations

This section addresses some of the general technical issues that must be considered when developing and implementing the plan and is intended to help make decisions.

3. Planning Considerations for IMS TM

This section focuses on technical issues related to the IMS TM environment.

4.Data Sharing and Shared Queues Considerations

This section reviews some technical issues related to IMS data sharing and shared queues.

5.MVS Parallel Sysplex Considerations

Here, we look at some technical topics related to IMS interact with MVS Parallel Sysplex.

6.Operation Considerations

Finally, we review technical topics related to IMS operation and recovery procedures.

7. Appendixes

The appendixes provide additional technical information that might be useful in performing some of the tasks. A sample list of tasks is included at the end of this redbook in Appendix E, “Migration Plan Task List” on page 233. This list includes references to the parts of this redbook that apply to each task in the list.

A list of useful Parallel Sysplex publications, other than the standard

IMS/ESA V6.1 product publications, is provided in Appendix D, “Parallel

Sysplex Publications” on page 231.

1.3 Prerequisite Knowledge

This redbook is written for those who are familiar with the following:

•IMS block-level data sharing definition requirements for IMS, IRLM, and the Coupling Facility

•IMS shared queues definition requirements for IMS (including the Common Queue Server) and the Coupling Facility

•Recovery procedures for failures in the IMS block-level data sharing environment

•Recovery procedures for failures in the shared queues environment

•Roles of IRLM and the Coupling Facility in supporting block-level data sharing

•Roles of the Common Queue Server and the Coupling Facility in supporting shared queues

1.4 Assumptions

The assumptions about the installation for which the plan is being developed are:

•The installation is in production with IMS/ESA V6.1 prior to the implementation of this plan.

•A Parallel Sysplex environment has been implemented prior to the implementation of this plan.

•The application (system) to be migrated has been identified.

•The existing IMS environment and its applications are to be cloned.

There is only one current IMS system to be cloned. Its workload will be split across multiple IMS systems which are as identical in function as possible. They can have different workload capacities.

2 IMS Parallel Sysplex Migration Planning Guide

Part 1. Developing the Plan

4 IMS Parallel Sysplex Migration Planning Guide

Chapter 2. Plan Development

This section addresses the development of the migration plan and identifies some of the steps and considerations you might encounter when developing the plan. The result of this exercise is not to ″perform″ any of the implementation tasks but to identify those tasks which must be done and to create a plan for accomplishing them. For example, the plan can identify as a task the establishment of a naming convention for system data sets. The naming convention itself is not a part of the plan, but is a result of implementing the plan.

2.1 Planning for Migration

The process of migrating to an IMS data sharing and/or shared queues Parallel Sysplex environment should be accomplished in three phases: a planning phase, a preparation phase, and an implementation phase.

2.1.1 Planning Phase

The purpose of this phase is to identify/document where you are coming from, where you are going, what you will do if there are failures, and to determine how the plan will be created, who has responsibility, what will be its content and format, what planning or project management tools will be used, and finally to develop the plan itself.

Below, we have identified four major steps in the planning phase. You might recognize fewer or more, but each step below has a purpose, and that purpose, must be satisfied in any planning process.

2.1.1.1 Understand the Existing Environment

The first step in the planning phase is to understand the existing environment. This includes knowing, for each application, the resource requirements (such as, CPU, I/O), service level requirements, schedules and workloads, connections to other subsystems, and the reasons for migrating (for instance, reduced costs or improved performance, capacity, or availability). You should also identify any

″inhibitors″ to migration, such as non-sharable resources.

The assumption here is that the target environment is replacing an existing environment for one or more reasons (for example, capacity, performance, availability, flexibility,...). However, the target environment must continue to provide the equivalent function with performance and availability at least as good as the existing environment. So, in order to define a target environment which will do this, it is first necessary to understand the existing environment. The following describes the characteristics of the existing environment that should be known before defining the target.

•Why are you migrating to this environment?

A major part of developing a migration plan is to choose the configuration to which the migration will be done. This configuration is affected by the reasons for making the migration. The migration to IMS data sharing and shared queues with Parallel Sysplex can be used to provide multiple benefits. These include, but are not limited to:

−Increased availability

−Increased capacity

−Incremental growth capability

−Operational flexibility

•What is the current workload?

This should be documented in terms that will facilitate the distribution of that workload over two or more (perhaps) processors and should include transaction volumes as well as batch/BMP and support jobs such as image copies, reorganizations, and so forth.

•Who are the heavy resource users?

Which of the above transactions or batch processes require the greatest number of, CPU or I/O resources, and which transactions are the highest volumes. It might be necessary to make special provisions for them in the target environment.

•What are the service level commitments?

What agreements exist for transaction response times, batch elapsed times and availability? Are users billed according to the resources they use?

•To what systems is the existing IMS connected?

This should include other IMSs, DB2s, CICSs, and any other ″intelligent″ systems or devices that might be sensitive to the identity of the IMS system to which they are connected.

•What are the online and batch schedules?

What are the hours of availability for online access and what is the ″batch window″ (if there is one)?

•Are there any batch or online dependencies?

Are there ″sequences″ of processes that must be maintained in the target environment. For example, transactions defined as SERIAL, implying a FIFO processing sequence, should be identified.

•Are any user exits sensitive to the identity of the IMS system on which they execute?

Look particularly at transaction manager exits and system exits as there will be multiple transaction managers with different IDs, connected, perhaps, to different subsystems (for instance, different CICSs or different DB2s) and with only part of the original network.

•Do any user-written programs process the IMS logs?

The logs will be quite different, with each log containing only part of the information that was on the original single-image log.

•What are the business-critical applications?

If one component of the target environment fails (for instance, one of two IMS systems) and can′t be immediately restarted, it might be necessary to

quiesce relatively unimportant work on the surviving system in order to shift the entire critical workload to that system. It might also be necessary to shift part (or all) of the network to the surviving system.

•Are there any non-sharable resources?

6 IMS Parallel Sysplex Migration Planning Guide

An installation can choose not to share some databases. (See 6.5, “Handling Databases That Are Not Shared” on page 42). These must be identified and plans made for their migration to the target system.

2.1.1.2 Define Target Environment

The next step in the migration planning phase is to define the configuration of the target environment. This includes the number of IMS subsystems in the data sharing group, shared queues group, VTAM generic resource group, the MVS system on which each IMS will run, other subsystems outside of the Parallel Sysplex environment to which the target IMS will connect ( for example, other IMSs, CICS, DB2), the coupling facilities to be used, and which systems will be used for various purposes. For example, one must know on which systems IMS BMPs will be run, or if applications are to be partitioned, on which systems they will run. Be sure the target environment satisfies the reasons for migration.

The elements of the target configuration include the following:

•MVS Systems

The MVS systems in the target configuration should be identified by the processors and LPARs on which they run and the types of work they will support. The types of work include the IMS subsystems and support processes they will handle.

•IMS Subsystems and Processes

These are IMS online systems (either IMS Transaction Manager, DCCTL, or DBCTL), IMS batch jobs, and IMS support processes. Support processes include database image copies, database reorganizations, log archiving, and definition jobs. The MVS systems on which they will run should be identified.

The use of each IMS online system should be identified.

−IMS TM

For IMS TM this includes the terminal networks that will use them, the ISC and MSC connections to other systems, APPC connections, the associated DB2 subsystems, the application programs, and transactions that will run on each system. Application programs include BMPs.

For IMS TM and DCCTL subsystems, special planning considerations will be required if shared queues, VTAM generic resources, and/or other Parallel Sysplex enhancements delivered with IMS/ESA V6.1 are to be used.

−DBCTL

For DBCTL this includes the CICS systems that will attach to them, the DB2 systems used by BMPs, and the application programs that will run on each system. Application programs include BMPs.

For cloned systems, it is assumed that all online transactions and programs will be run on each system. For performance, operational, or affinity reasons, there may be exceptions. These should be understood, and the target configuration must account for these considerations. Typically, BMPs and IMS batch jobs will be directed to particular IMS or MVS systems. Many installations will want to run them on only one MVS system.

• Coupling Facilities

Chapter 2. Plan Development 7

The coupling facilities and coupling facility structures to support IMS should be identified. This includes structure sizes and the placement of these structures in support of:

−Data sharing structures

-IRLM (lock structure)

-VSAM buffer invalidation structure (directory-only cache structure)

-OSAM buffer invalidation/cache structure (store-through cache structure)

-Shared DEDB VSO structure(s) (store-in cache structure)

−Shared Queues

-Message queue and EMH queue primary and overflow structures (list structures)

-MVS logger structures (list structures)

−VTAM Generic Resource structure (list structure)

2.1.1.3 Define Degraded Mode Environment

Next you must decide what you will do if something fails. Since a Parallel Sysplex consists of multiple MVS and IMS systems, an installation should plan what it will do if one or more components fail. For example, there may be certain applications or systems that are more critical to the business and therefore should have preference to be available when there is an outage of part of the system. This is called degraded mode processing.

During this phase, you should determine both the processing and business impact of the failure of any component of the target environment. Identify those applications which must be given priority in a degraded processing environment. You must also consider what users who are connected to a failed component should do (such as, log on to another IMS?).

Some tasks which should be included in this phase are:

•

Perform a ″component failure impact analysis (CFIA)″ for critical components Prioritize applications for degraded mode processing

Identify applications to run in degraded mode

Identify network terminals and connections to be reconnected to another system if one system fails

2.1.1.4 Develop the Plan

The plan should recognize the following two phases of the migration process: preparation and implementation. Although this document does not prescribe a format for the migration plan, the following elements should be included:

•

Tasks - What must be done?

Responsibility - Who is responsible to see that it gets done?

Dependencies - Is any task a prerequisite to another task?

Duration - How long should each task take?

Schedule - When must it be done - start/complete/drop-dead dates?

Status - A mechanism for monitoring progress?

8 IMS Parallel Sysplex Migration Planning Guide

Appendix E, “Migration Plan Task List” on page 233 is a list of tasks that have been identified which should be a part of the migration plan.

2.1.2 Preparation Phase

Most of the tasks identified in the migration plan are implemented during the preparation phase. The plan may say, for example, that a naming convention must be established for system data sets. During this phase, that naming convention will be developed. Or the plan may say that operational procedures must be updated. During this phase, those procedures are updated.

Some of the tasks in this phase will be ″decision″ type tasks (for instance, how many copies of RESLIB do I want?). Others will be ″implementing″ some of these decisions (such as, making two copies of RESLIB). At the conclusion of this phase, you are ready to migrate your existing system to production.

2.1.3 Implementation Phase

The final phase in the migration process is the actual implementation. That is, the existing environment will be converted to an operational IMS Parallel Sysplex environment. The actual ″implementation plan″ will probably be produced as part of the preparation phase as it is unlikely that enough information will be available during planning to generate this plan.

Chapter 2. Plan Development 9

10 IMS Parallel Sysplex Migration Planning Guide

Part 2. Planning Considerations

12 IMS Parallel Sysplex Migration Planning Guide

+ 246 hidden pages