IBM SC34-7012-01 - Chapter 2. Resource recovery in CICS; Units of work

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Part 1. CICS recovery and restart concepts

It is very important that a transaction processing system such as CICS can restart

and recover following a failure. This section describes some of the basic concepts

of the recovery and restart facilities provided by CICS.

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Default Chapter5
- Table of Contents5
- Programs5
- Rebuilding the CICS State5
- Shunt5
- Shutdown5
- Transient Data5
- Communication6
- Transaction)6
- Unit of Work Recovery6
- URIMAP Definition6
- Systems Administration7
- Transaction7
- Xrc7
- Trademarks8
- How to Use this Book9
Preface9
- What this Book Is about9
- What You Need to Know to Understand this Book9
- Who Should Read this Book9
Part 1. CICS Recovery and Restart Concepts13
Chapter 1. Recovery and Restart Facilities15
- Maintaining the Integrity of Data15
- Minimizing the Effect of Failures16
- The Role of CICS16
- Recoverable Resources17
- CICS Backward Recovery (Backout)17
  - Dynamic Transaction Backout18
  - Emergency Restart Backout18
- CICS Forward Recovery19
  - Forward Recovery of CICS Data Sets19
- Failures that Require CICS Recovery Processing20
Chapter 2. Resource Recovery in CICS25
- Units of Work25
- CICS Recovery Manager29
- CICS System Log33
  - Information Recorded on the System Log33
  - System Activity Keypoints34
- Forward Recovery Logs34
- User Journals and Automatic Journaling34
Chapter 3. Shutdown and Restart Recovery37
- Normal Shutdown Processing37
- Immediate Shutdown Processing (PERFORM SHUTDOWN IMMEDIATE)40
- Shutdown Requested by the Operating System41
- Uncontrolled Termination42
- The Shutdown Assist Transaction42
- Cataloging CICS Resources43
  - Global Catalog43
  - Local Catalog44
- Shutdown Initiated by CICS Log Manager45
  - Effect of Problems with the System Log45
- How the State of the CICS Region Is Reconstructed46
- Recovery with VTAM Persistent Sessions50
  - Running with Persistent Sessions Support50
  - Running Without Persistent Sessions Support52
Part 2. Recovery and Restart Processes55
- Communication55
Chapter 4. CICS Cold Start57
- Chapter 4, "CICS Cold Start57
- Starting CICS with the START=COLD Parameter57
- Files58
- Starting CICS with the START=INITIAL Parameter62
  - User Journals63
Chapter 5. CICS Warm Restart65
- Chapter 5, "CICS Warm Restart65
- Rebuilding the CICS State after a Normal Shutdown65
Chapter 6. CICS Emergency Restart73
- Chapter 6, "CICS Emergency Restart73
- Recovering after a CICS Failure73
- Rebuilding the CICS State after an Abnormal Termination74
Chapter 7. Automatic Restart Management79
- Chapter 7, "Automatic Restart Management79
- CICS ARM Processing79
- CICS Restart JCL and Parameters81
- Workload Policies82
- Connecting to VTAM82
  - The COVR Transaction83
  - Messages Associated with Automatic Restart83
- Automatic Restart of CICS Data-Sharing Servers83
  - Server ARM Processing83
Chapter 8. Unit of Work Recovery and Abend Processing85
- Chapter 8, "Unit of Work Recovery and Abend Processing85
- Unit of Work Recovery85
- Investigating an Indoubt Failure97
- Recovery from Failures Associated with the Coupling Facility100
- Transaction Abend Processing104
  - Exit Code104
  - Abnormal Termination of a Task105
- Actions Taken at Transaction Failure106
- Processing Operating System Abends and Program Checks106
Chapter 9. Communication Error Processing109
- Terminal Error Processing109
  - Node Error Program (DFHZNEP)109
  - Terminal Error Program (DFHTEP)109
- Intersystem Communication Failures110
Part 3. Implementing Recovery and Restart111
Chapter 10. Planning Aspects of Recovery113
- Application Design Considerations113
- System Definitions for Recovery-Related Functions116
  - System Log Stream116
  - System Recovery Table (SRT)116
- Documentation and Test Plans117
  - Transaction List Table (XLT)117
Chapter 11. Defining System and General Log Streams119
- Defining Log Streams to MVS120
- Defining System Log Streams120
- Defining Forward Recovery Log Streams128
  - Model Log Streams for CICS General Logs129
  - Merging Data on Shared General Log Streams130
- Defining the Log of Logs130
  - Log of Logs Failure131
  - Reading Log Streams Offline131
- Effect of Daylight Saving Time Changes132
  - Adjusting Local Time132
  - Time Stamping Log and Journal Records132
Chapter 12. Defining Recoverability for CICS-Managed Resources135
- Recovery for Transactions135
  - Defining Transaction Recovery Attributes135
- Recovery for Files137
- Recovery for Intrapartition Transient Data143
- Recovery for Temporary Storage147
  - Backward Recovery147
  - Forward Recovery148
- Recovery for Web Services148
Chapter 13. Programming for Recovery153
- Designing Applications for Recovery153
  - Splitting the Application into Transactions153
  - SAA-Compatible Applications155
- Program Design155
- Managing Transaction and System Failures161
- Locking (Enqueuing On) Resources in Application Programs166
- User Exits for Transaction Backout172
Chapter 14. Using a Program Error Program (PEP)175
- The CICS-Supplied PEP175
- Your Own PEP176
- Omitting the PEP177
Chapter 15. Resolving Retained Locks on Recoverable Resources179
- Quiescing RLS Data Sets179
  - The RLS Quiesce and Unquiesce Functions180
- Switching from RLS to Non-RLS Access Mode184
- Coupling Facility Data Table Retained Locks194
Chapter 16. Moving Recoverable Data Sets that Have Retained Locks195
- Procedure for Moving a Data Set with Retained Locks195
Chapter 17. Forward Recovery Procedures199
- Forward Recovery of Data Sets Accessed in RLS Mode199
  - Recovery of Data Set with Volume Still Available200
  - Recovery of Data Set with Loss of Volume201
- Forward Recovery of Data Sets Accessed in Non-RLS Mode210
- Procedure for Failed RLS Mode Forward Recovery Operation210
- Procedure for Failed Non-RLS Mode Forward Recovery Operation213
Chapter 18. Backup-While-Open (BWO)215
- BWO and Concurrent Copy215
  - BWO and Backups215
- BWO Requirements216
  - Hardware Requirements217
- Which Data Sets Are Eligible for BWO217
- How You Request BWO218
  - Specifying BWO Using Access Method Services218
  - Specifying BWO on CICS File Resource Definitions219
- Removing BWO Attributes220
- Systems Administration220
- BWO Processing221
- An Assembler Program that Calls DFSMS Callable Services230
Chapter 19. Disaster Recovery235
- Why Have a Disaster Recovery Plan235
- Disaster Recovery Testing236
- Six Tiers of Solutions for Off-Site Recovery237
- Disaster Recovery and High Availability246
- CICS Emergency Restart Considerations251
  - Indoubt and Backout Failure Support251
  - Remote Site Recovery for RLS-Mode Data Sets251
- Final Summary252
Part 4. Appendixes253
Notices255
- Operation of255
- Trademarks256
Bibliography257
- CICS Books for CICS Transaction Server for Z/Os257
- Cicsplex SM Books for CICS Transaction Server for Z/Os258
- Other CICS Publications258
Accessibility259
- Index261

IBM SC34-7012-01 - Chapter 2. Resource recovery in CICS; Units of work

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