Performing fallback

If a problem occurs after Tivoli Workload Scheduler for z/OS has been active as a production system for some time, and the problem is serious enough, you might need to stop the new system and return the workload to the previous system. You can do this using a procedure called fallback, if the Tivoli Workload Scheduler for z/OS data sets are usable. The procedure is:

  1. Run the EQQPCS01 and EQQPCS02 jobs to allocate new data sets for the old production system. The current data sets, or a copy, used by the Tivoli Workload Scheduler for z/OS systems should be kept for problem determination purposes.
  2. Run the EQQPCS05 job to create the work directory.
  3. If required, close down the systems in the same way as during migration. This is required if the current plan on the OPCA system is intact and job tracking is working normally.
  4. If possible, create up-to-date data sets for the long-term plan and new current plan for the OPCA system. Do not submit a REPLAN job prior to shutdown, unless the PERMANENT option was used for SSCMNAME on the converted system, or if SSCMNAME was not specified. If SSCMNAME(EQQSSCMJ,TEMPORARY) was used, message EQQZ190E will be issued if a REPLAN job is started after the controller is shut down.
  5. Build VSAM data sets for the old system by running the EQQICNVS job to convert Tivoli Workload Scheduler for z/OS files to their previous format. Note that the job log to be retrieved by the Data Store will be left as it is.
  6. Start the OPCA and OPCB systems again using the converted files and start OPCS.
    Note:
    You might find it useful to specify JOBSUBMIT(NO) and FTWJSUB(NO) on the JTOPTS initialization statement so that work is not submitted when you start OPCA. When you have checked that old system has started without errors, you can activate job submission using the Service Functions dialog.
  7. If the new current plan (NCP) data set is not fully up-to-date because you could not run the daily plan program, use the MCP dialog to update the status of operations to make the current plan up-to-date.
  8. Start the OPCC and OPCD systems again. Use the SSCMNAME keyword on the JTOPTS initialization to load the current subsystem communication module for the release you are falling back to. Activate MVS™ systems as required.
Note:
If you experience problems with your Tivoli Workload Scheduler for z/OS system and you need to migrate back to an earlier release, you must consider the impact that this will have on all aspects of your configuration. This is especially important for connectivity items. Consider all possible migration actions when planning the migration and fallback procedures for your installation.

In the following example, all VSAM files are converted from the current version of Tivoli Workload Scheduler for z/OS to the format of the previous release of the product. The tasks to perform immediately before this job are listed here in order:

  1. Verify JS1 as the active JCL repository in option 6.6 on the controller. If JS2 is the active JCL repository, use that as input, but be sure to use JS1 as output because Tivoli Workload Scheduler for z/OS by default uses JS1 as the active JCL repository when you start a subsystem with an empty checkpoint data set.
  2. Shut down the controller normally. Verify this using the message log. Check that a current plan backup process was completed after the stop command was received by the subsystem.
  3. Submit a EQQPCS01 job that you generate from EQQJOBS to reallocate the VSAM clusters.
  4. Check that a daily plan batch process had not been submitted on the system prior to shutdown. Therefore the Tivoli Workload Scheduler for z/OS CP1 is used as input, and the output is the NCP.
|//OPCBAK JOB (777777,777),'Fallback to V8R5M1',MSGLEVEL=(1,1),
|//     NOTIFY=&SYSUID,MSGCLASS=H,CLASS=A
|//*
|//CONVERT  EXEC PGM=EQQICTOP,REGION=2048K
|//STEPLIB   DD  DISP=SHR,DSN=OPCESA.INST.LOADLIB
|//EQQMLIB   DD  DISP=SHR,DSN=OPCESA.INST.SEQQMSG0
|//EQQMLOG   DD  SYSOUT=*
|//EQQADIN   DD  DISP=SHR,DSN=CCOPC.OPCC.AD
|//EQQADOUT  DD  DISP=OLD,DSN=CCOPC.OPCC.OLD.AD
|//EQQWSIN   DD  DISP=SHR,DSN=CCOPC.OPCC.WS
|//EQQWSOUT  DD  DISP=OLD,DSN=CCOPC.OPCC.OLD.WS
|//EQQCPIN   DD  DISP=SHR,DSN=CCOPC.OPCC.CP1
|//EQQCPOUT  DD  DISP=OLD,DSN=CCOPC.OPCC.OLD.NCP
|//EQQLTIN   DD  DISP=SHR,DSN=CCOPC.OPCC.LT
|//EQQLTOUT  DD  DISP=OLD,DSN=CCOPC.OPCC.OLD.LT
|//EQQJSIN   DD  DISP=SHR,DSN=CCOPC.OPCC.JS1
|//EQQJSOUT  DD  DISP=OLD,DSN=CCOPC.OPCC.OLD.JS1
|//EQQOIIN   DD  DISP=SHR,DSN=CCOPC.OPCC.OI
|//EQQOIOUT  DD  DISP=OLD,DSN=CCOPC.OPCC.OLD.OI
|//EQQSIIN   DD  DISP=OLD,DSN=CCOPC.OPCC.SI
|//EQQSIOUT  DD  DISP=OLD,DSN=CCOPC.OPCC.OLD.SI
|//EQQCXIN   DD  DISP=OLD,DSN=CCOPC.OPCC.CX
|//EQQCXOUT  DD  DISP=OLD,DSN=CCOPC.OPCC.OLD.NCX 
|//EQQRDIN   DD  DISP=OLD,DSN=CCOPC.OPCC.RD
|//EQQRDOUT  DD  DISP=OLD DSN=CCOPC.OPCC.OLD.RD
|//SYSIN     DD  *
|  /* FALLBACK FROM Tivoli Workload Scheduler for z/OS V8.6.0 to Tivoli OPC V8.5.1 IS ASSUMED */
|  CONVERT FILE(AD) FROMREL(TWSV8R6M0) TOREL(TWSV8R5M1)
|  CONVERT FILE(CP) FROMREL(TWSV8R6M0) TOREL(TWSV8R5M1)
|  CONVERT FILE(WS) FROMREL(TWSV8R6M0) TOREL(TWSV8R5M1)
|  CONVERT FILE(LT) FROMREL(TWSV8R6M0) TOREL(TWSV8R5M1)
|  CONVERT FILE(JS) FROMREL(TWSV8R6M0) TOREL(TWSV8R5M1)
|  CONVERT FILE(OI) FROMREL(TWSV8R6M0) TOREL(TWSV8R5M1)
|  CONVERT FILE(CX) FROMREL(TWSV8R6M0) TOREL(TWSV8R5M1)
|  CONVERT FILE(RD) FROMREL(TWSV8R6M0) TOREL(TWSV8R5M1)
|  CONVERT FILE(SI) FROMREL(TWSV8R6M0) TOREL(TWSV8R5M1)