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IBM SC34-7012-01 Recovery and Restart Guide, CICS Transaction Server for z/OS, Version 4 Release

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CICS Transaction Server for z/OS
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Recovery and Restart Guide

SC34-7012-01

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IBM SC34-7012-01 manual Recovery and Restart Guide, CICS Transaction Server for z/OS, Version 4 Release

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SC34-7012-01 Recovery and Restart GuideCICS Transaction Server for z/OS Version 4 ReleasePage SC34-7012-01 Recovery and Restart GuideCICS Transaction Server for z/OS Version 4 ReleaseCopyright IBM Corporation 1982 Chapter 2. Resource recovery in CICS ContentsPart 1. CICS recovery and restart concepts Part 2. Recovery and restart processesChapter 8. Unit of work recovery and Part 3. Implementing recovery andChapter 9. Communication error recoveryChapter 18. Backup-while-open BWO Chapter 13. Programming for recoveryChapter 16. Moving recoverable data Chapter 17. Forward recoveryNotices Chapter 19. Disaster recoveryAccessibility Part 4. AppendixesWho should read this book How to use this bookPreface What this book is aboutviii CICS TS for z/OS 4.1 Recovery and Restart Guide Changes in CICS Transaction Server for z/OS, Version 4 Release x CICS TS for z/OS 4.1 Recovery and Restart Guide Part 1. CICS recovery and restart concepts 2 CICS TS for z/OS 4.1 Recovery and Restart Guide Chapter 1. Recovery and restart facilities Maintaining the integrity of dataLogging changes Minimizing the effect of failures The role of CICS4 CICS TS for z/OS 4.1 Recovery and Restart Guide CICS backward recovery backout Recoverable resourcesEmergency restart backout Dynamic transaction backoutForward recovery of CICS data sets CICS forward recoveryFailures that require CICS recovery processing CICS recovery processing following a communication failureForward recovery for non-VSAM resources XCF/MRO partner failures CICS recovery processing following a transaction failure CICS recovery processing following a system failure10 CICS TS for z/OS 4.1 Recovery and Restart Guide v Back out recoverable resources 12 CICS TS for z/OS 4.1 Recovery and Restart Guide Chapter 2. Resource recovery in CICS Units of workShunted units of work Active and retained states for locks LocksEXEC CICS CREATE TERMINAL Synchronization pointsEXEC CICS CREATE TERMINAL EXEC CICS CREATE CONNECTION COMPLETE EXEC CICS DISCARD CONNECTION EXEC CICS DISCARD TERMINALExamples of synchronization points EXEC CICS CREATE CONNECTION COMPLETE EXEC CICS DISCARD CONNECTIONEXEC CICS DISCARD TERMINAL CICS recovery manager Figure 3. CICS recovery manager and resources it works with FC/RLSRecovery v Coordinating recoverable conversations to remote nodesCoordinating updates to local resources Managing indoubt units of work Coordinating updates in distributed units of workResynchronization after system or connection failure CICS system logInformation recorded on the system log Forward recovery logs System activity keypointsUser journals and automatic journaling Input or output messages from terminals accessed through VTAM 24 CICS TS for z/OS 4.1 Recovery and Restart Guide Chapter 3. Shutdown and restart recovery Normal shutdown processingFirst quiesce stage Third quiesce stage Second quiesce stageShunted units of work at shutdown Warm keypointsFlushing journal buffers Immediate shutdown processing PERFORM SHUTDOWN IMMEDIATEPERFORM IMMEDIATE not recommended Shutdown requested by the operating system Uncontrolled termination The shutdown assist transaction30 CICS TS for z/OS 4.1 Recovery and Restart Guide Global catalog Cataloging CICS resourcesLocal catalog Shutdown initiated by CICS log manager Effect of problems with the system logDFHRM0405 How the state of the CICS region is reconstructedDFHRM0402 DFHRM0403 and DFHRM0404About this task Overriding the type of start indicatorWarm restart Emergency restartRecovery of data during an emergency restart Cold startAn initial start of CICS Dynamic RLS restart MNPS, multinode persistent sessions Recovery with VTAM persistent sessionsRunning with persistent sessions support SNPS, single-node persistent sessionsSituations in which sessions are not reestablished Running without persistent sessions support Situations in which VTAM does not retain sessionsSET VTAM FORCECLOSE SET VTAM IMMCLOSE SET VTAM CLOSED regions that do have persistent sessions support 42 CICS TS for z/OS 4.1 Recovery and Restart Guide Part 2. Recovery and restart processes 44 CICS TS for z/OS 4.1 Recovery and Restart Guide Chapter 4. CICS cold start Starting CICS with the START=COLD parameterAbout this task VSAM FilesData tables Temporary storageTransient data Temporary storage data sharing serverLIBRARY resources Resource definitions dynamically installedTransactions Journal names and journal modelsTerminal control resources Committing and cataloging resources installed from the CSDSingle resource install Monitoring and statisticsStarting CICS with the START=INITIAL parameter Installable set installDistributed transaction resources Dump tableinformation saved in the system log from a previous run. The primary and secondary system log streams are purged and CICS begins writing a new system log 52 CICS TS for z/OS 4.1 Recovery and Restart Guide Rebuilding the CICS state after a normal shutdown Chapter 5. CICS warm restartFiles Reconnecting to SMSVSAM for RLS accessData set name blocks Recreating non-RLS retained locksTemporary storage TDINTRA=NOEMPTY the defaultTDINTRA=EMPTY Trigger levels for TERMINAL and SYSTEM onlyPrograms No autoinstall for programsTransactions LIBRARY resourcesAutoinstall for programs Start requestsMonitoring and statistics Terminal control resources CSD-defined resource definitionsTCAM and sequential BSAM devices Journal names and journal modelsURIMAP definitions and virtual hosts v Different TCT from last run. CICS installs the TCT only, and does not apply the warm keypoint information, effectively making this a cold start for these devicesDistributed transaction resources 60 CICS TS for z/OS 4.1 Recovery and Restart Guide Driving backout processing for in-flight units of work Recovering after a CICS failureRecovering information from the system log Chapter 6. CICS emergency restart62 CICS TS for z/OS 4.1 Recovery and Restart Guide Effect of delayed recovery on PLTPI processingOther backout processing Rebuilding the CICS state after an abnormal terminationTemporary storage Reconnecting to SMSVSAM for RLS accessRLS restart processing and orphan locks Recreating non-RLS retained locksCSD-defined resource definitions 64 CICS TS for z/OS 4.1 Recovery and Restart GuideStart requests Terminal control resourcesis successful, but CICS abnormally terminates before the catalog can be updated, CICS recovers the information from the forward recovery records on the system log Distributed transaction resourcesTCAM and sequential BSAM devices 66 CICS TS for z/OS 4.1 Recovery and Restart Guide Chapter 7. Automatic restart management CICS ARM processingRestrictions Before you begin Registering with ARMWaiting for predecessor subsystems De-registering from ARMChapter 7. Automatic restart management Failing to registerARM couple data sets CICS restart JCL and parametersConnecting to VTAM Workload policiesCICS START options Server ARM processing The COVR transactionMessages associated with automatic restart Automatic restart of CICS data-sharing serversServer initialization parameters for ARM support Server commands for ARM supportCANCEL RESTART=NOYES Waiting on events during initializationCommit-failed Chapter 8. Unit of work recovery and abend processingUnit of work recovery In-flight-failedTransaction backout Backout-failedIndoubt-failed Files BDAM files and VSAM ESDS filesCICS data tables START requests START with recoverable data no PROTECTIntrapartition transient data Auxiliary temporary storageRestart of started transactions START with recoverable data PROTECTSTART with nonrecoverable data no PROTECT START with nonrecoverable data PROTECTEXEC CICS CANCEL requests Basic mapping support BMS messagesAuxiliary temporary storage Backout-failed recoveryDisposition of data sets after backout failures I/O errorTransient data Retrying backout-failed units of workOpen error Logical delete not performedSMSVSAM server failure Coupling facility cache structure failure DFSMSdss non-BWO backup in progressDuplicate key error SMSVSAM server recycle during backoutCommit-failed recovery Lock structure full errorNone of the above Files Indoubt failure recoveryInvestigating an indoubt failure Intrapartition transient dataAuxiliary temporary storage The WAITSTATE of Shunted shows that this UOW has been suspended We can now see that Cache failure support Recovery from failures associated with the coupling facilityAbout this task Lost locks recoveryRebuilding the lock structure Notifying CICS of SMSVSAM restart90 CICS TS for z/OS 4.1 Recovery and Restart Guide Performing lost locks recovery for failed units of workMVS system recovery and sysplex recovery Connection failure to a coupling facility cache structureConnection failure to a coupling facility lock structure Exit code Transaction abend processingTransaction restart Abnormal termination of a taskProcessing operating system abends and program checks Actions taken at transaction failurev If a match is not found, CICS is terminated 96 CICS TS for z/OS 4.1 Recovery and Restart Guide Terminal error program DFHTEP Chapter 9. Communication error processingTerminal error processing Node error program DFHZNEPIntersystem communication failures Part 3. Implementing recovery and restart 100 CICS TS for z/OS 4.1 Recovery and Restart Guide Chapter 10. Planning aspects of recovery Questions relating to recovery requirementsApplication design considerations Validate the recovery requirements statement About this task Designing the end user’s restart procedureEnd user’s standby procedures Communications between application and userSecurity System definitions for recovery-related functionsSystem recovery table SRT Resource definitions for recoveryProgram list table PLT Documentation and test plansTransient data queues Temporary storage tablev Forecast the exceptional conditions that can be expected System logging recovery purposes onlyForward recovery logging Chapter 11. Defining system and general log streamsGeneral log streams Defining log streams to MVSDefining system log streams System log streamsSpecifying a JOURNALMODEL resource definition Without a JOURNALMODEL definitionWith a JOURNALMODEL definition Model log streams for CICS system logs Recovery considerations2-Way Sysplex Activity keypointing Varying the model log stream nameAbout this task About this task Keeping system log data to a minimumLog-tail deletion Moving units of work to the secondary logAbout this task About this task Writing user-recovery dataAvoiding retention periods on the system log Retrieving user records from the system logAbout this task Defining forward recovery log streamsAbout this task Procedure Long-running transactionsWhat to do next Model log streams for CICS general logsMerging data on shared general log streams Defining the log of logsAbout this task About this task Log of logs failureReading log streams offline About this taskAbout this task Adjusting local timeEffect of daylight saving time changes Time stamping log and journal recordsOffline utility program, DFHJUP 122 CICS TS for z/OS 4.1 Recovery and Restart Guide RESTARTNOYES Chapter 12. Defining recoverability for CICS-managed resourcesRecovery for transactions Defining transaction recovery attributesACTIONBACKOUTCOMMIT Indoubt options for distributed transactionsSPURGENOYES TPURGENOYESSharing data sets with batch jobs Recovery for filesFile-owning regions and RLS access VSAM filesBackward recovery Basic direct access method BDAMDefining files as recoverable resources Forward recoveryBACKUPTYPEDYNAMIC VSAM files accessed in non-RLS modeRECOVERYALL RECOVERYBACKOUTONLYNONE VSAM files accessed in RLS modeInquiring on recovery attributes LOGNONEUNDOALLOverriding open failures at the XFCNREC global user exit File recovery attribute consistency checking non-RLSBDAM files The CSD data setAbout this task CICS responses to file open requestsBackward recovery Implementing forward recovery with user-written utilitiesImplementing forward recovery with CICS VSAM Recovery MVS/ESA Recovery for intrapartition transient dataPhysical recovery Logical recoveryNo recovery Forward recoveryInput extrapartition data sets Recovery for extrapartition transient dataBackward recovery Using post-initialization PLTPI programsRecovery for temporary storage Output extrapartition data setsGROUPTSRECOV PREFIXDF LOCATIONAUXILIARY RECOVERYYES Recovery for Web servicesConfiguring CICS to support persistent messages Forward recoveryProcedure Defining local queues in a service providerProcedure Results What to do nextPersistent message processing Error processingFor example, your recovery transaction could 140 CICS TS for z/OS 4.1 Recovery and Restart Guide About this task Procedure Chapter 13. Programming for recoveryDesigning applications for recovery Splitting the application into transactions142 CICS TS for z/OS 4.1 Recovery and Restart Guide Example What to do next Relationships between processing unitsProcedure SAA-compatible applicationsProgram design Dividing transactions into units of workProcessing dialogs with users Conversational processingPseudoconversational processing CICS recoverable resources Mechanisms for passing data between transactionsMain storage areas User files and DL/I and DB2 databases Designing to avoid transaction deadlocksTemporary storage auxiliary Transient data queuesProcedure Implications of interval control START requestsTerminal paging through BMS Using transient data queuesImplications of automatic task initiation TD trigger level Implications of presenting large amounts of data to the userAbout this task Managing transaction and system failuresTransaction failures About this taskHANDLE ABEND commands EXEC CICS SYNCPOINT ROLLBACK commandDynamic transaction backout Transaction restart after DTB Use of the program error program DFHPEPSystem failures Handling abends and program level abend exitsProcessing the IOERR condition CommandInformation provided START TRANSID commands PL/I programs and error handlingLocking enqueuing on resources in application programs Nonrecoverable files Implicit locking for filesAbout this task Recoverable files v READ for UPDATE v WRITE v DELETE Implicit enqueuing on logically recoverable TD destinations Implicit enqueuing on recoverable temporary storage queuesv WRITEQ TD v READQ TD v DELETEQ TD Sequential methods HSAM, HISAM, SHISAM Implicit enqueuing on DL/I databases with DBCTLExplicit enqueuing by the application programmer Direct methods HDAM, HIDAMdeadlock Possibility of transaction deadlockWhere you can add your own code User exits for transaction backoutAbout this task Procedure XRCINIT exitXRCINPT exit XFCBFAIL global user exitCoding transaction backout exits XFCLDEL global user exitXFCBOVER global user exit XFCBOUT global user exitAbout this task Chapter 14. Using a program error program PEPThe CICS-supplied PEP ProcedureYour own PEP Omitting the PEP Chapter 14. Using a program error program PEPAbout this task 166 CICS TS for z/OS 4.1 Recovery and Restart Guide About this task Chapter 15. Resolving retained locks on recoverable resourcesQuiescing RLS data sets About this taskIllustration of the quiesce flow across two CICS regions The RLS quiesce and unquiesce functionsChapter 15. Resolving retained locks on recoverable resources Other quiesce interface functions Non-BWO data set backup startForward recovery complete Non-BWO data set backup endBWO backup start BWO backup endQuiesce coupling facility cache available Switching from RLS to non-RLS access modeLost locks recovery complete Exception for read-only operationsWhat can prevent a switch to non-RLS access mode? About this task Resolving retained locks before opening data sets in non-RLS modeInvestigating which retained locks are held and why ProcedureINQUIRE DSNAME INQUIRE UOWDSNFAILAbout this task 176 CICS TS for z/OS 4.1 Recovery and Restart Guide SHCDS LIST subcommandsResolving retained locks and preserving data integrity About this task ProcedureAbout this task Choosing data availability over data integrityDFH0BAT2 CEMT command examplesThe batch-enabling sample programs DFH0BAT1NORMAL SET DSNAME’RLS.ACCOUNTS.ESDS.DBASE1’ RETRYSTATUS RESULTS - OVERTYPE TO MODIFY DsnRLS.ACCOUNTS.ESDS.DBASE1Overriding retained locks The PERMITNONRLSUPDATE subcommandThe DENYNONRLSUPDATE subcommand A special case lost locksPost-batch processing Coupling facility data table retained locks About this task Chapter 16. Moving recoverable data sets that have retained locksProcedure for moving a data set with retained locks Using the REPRO methodSHCDS FRBIND SHCDS FRRESETRRSHCDS FRSETRR SHCDS FRUNBINDUsing the EXPORT and IMPORT functions Chapter 16. Moving recoverable data sets that have retained locksAbout this task About this task Rebuilding alternate indexesChapter 17. Forward recovery procedures Forward recovery of data sets accessed in RLS modeAbout this task 5. Restore the backup Recovery of data set with volume still available3. Issue FRSETRR 4. Issue FRUNBIND9. Alter the new data set name Recovery of data set with loss of volume10. Issue the FRBIND subcommand 11. Issue the FRRESETRR subcommandVolume recovery procedure using CFVOL QUIESCE 1. VARY SMS,CFVOLvolser,QUIESCE Example of recovery using data set backup 5. We terminated the SMSVSAM servers using the MVS command INQUIRE UOWDSNFAIL DSNRLSADSW.VF01D.BANKACCT 194 CICS TS for z/OS 4.1 Recovery and Restart GuideThese commands are issued to each CICS AOR that requires access 196 CICS TS for z/OS 4.1 Recovery and Restart Guide Example of recovery using volume backupCatalog recovery 4. Run the forward recovery utility Forward recovery of data sets accessed in non-RLS modeProcedure for failed RLS mode forward recovery operation 3. Restore the backup1. Tidy up any outstanding CICS recovery work, as follows 1 Force shunted indoubt units of work using SET DSNAME Procedure for failed non-RLS mode forward recovery operation 202 CICS TS for z/OS 4.1 Recovery and Restart Guide Chapter 18. Backup-while-open BWO BWO and backupsBWO and concurrent copy Previous product BWO requirementsComponent name Full DFSMS/MVS nameHardware requirements Which data sets are eligible for BWOVSAM control interval or control area split TYPECICS Specifying BWO using access method servicesHow you request BWO ResultsAbout this task Specifying BWO on CICS file resource definitionsProcedure Systems administrationRemoving BWO attributes Batch jobsBWO processing First file opened in non-RLS mode against a cluster File openingBack-level data sets Subsequent files opened when use count is zero Subsequent files opened when use count is not zeroRestriction for VSAM upgrade set File closing non-RLS modeImmediate or uncontrolled shutdown Data set backup and restoreShutdown and restart Controlled shutdownInvalid state changes for BWO attributes VSAM access method servicesNon-SMS managed storage Forward recovery loggingData set restore Data setsForward recovery Recovery point non-RLS modeAbout this task Recovering VSAM spheres with AIXsAn assembler program that calls DFSMS callable services DATEPACK DATETIMEDTTENTHS RECOVPTPLOAD 220 CICS TS for z/OS 4.1 Recovery and Restart GuidePRGCONT BWOFLAGS12,ZEROESEND PROG 222 CICS TS for z/OS 4.1 Recovery and Restart Guide Why have a disaster recovery plan? Chapter 19. Disaster recoveryDisaster recovery testing Six tiers of solutions for off-site recovery Tier 0 no off-site dataTier 1 - physical removal The drawbacks are Tier 2 - physical removal with hot site Tier 3 - electronic vaultingTier Tier 0-3 solutions Tier 0 Tier 4 - active secondary site230 CICS TS for z/OS 4.1 Recovery and Restart Guide Figure 22. Disaster recovery tier 4 active secondary siteTier 6 - minimal to zero data loss Tier 5 - two-site, two-phase commitFigure 24 summarizes the tier 6 solution Tier 4 Tier 4-6 solutionsPeer-to-peer remote copy PPRC and extended remote copy XRC Disaster recovery and high availabilityUse XRC for high volume transactions PPRC or XRC?Use PPRC for high value transactions 236 CICS TS for z/OS 4.1 Recovery and Restart Guide Remote Recovery Data FacilityOther benefits of PPRC and XRC Forward recoveryRRDF Choosing between RRDF and 3990-6 solutionsDisaster recovery personnel considerations About this task238 CICS TS for z/OS 4.1 Recovery and Restart Guide Disaster recovery facilitiesMVS system logger recovery support Returning to your primary siteCICS VR shadowing CICS VSAM Recovery QSAM copyRemote Recovery Data Facility support Remote site recovery for RLS-mode data setsFinal summary Copyright IBM Corp. 1982 Part 4. Appendixes242 CICS TS for z/OS 4.1 Recovery and Restart Guide Notices 244 CICS TS for z/OS 4.1 Recovery and Restart Guide TrademarksCICS books for CICS Transaction Server for z/OS Access to CICSAdministration BibliographyGeneral Administration and ManagementCICSPlex SM books for CICS Transaction Server for z/OS Other CICS publicationsAccessibility 248 CICS TS for z/OS 4.1 Recovery and Restart Guide Index A files continued DL/I continuedlocking continued Page Readers’ Comments - Wed Like to Hear from You Recovery and Restart Guide Publication No. SC34-7012-01CICS Transaction Server for z/OS Version 4 Release IBM United Kingdom Limited Readers’ Comments - Wed Like to Hear from YouSC34-7012-01 SC34-7012-01Page SC34-7012-01