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CICS VR-Executing batch backout when the RCDSs are unavailable

By dionne A Nerissa posted 8 days ago

  

Executing Batch Backout While RCDS are Unavailable

Some terminology

  1. Batch Backout is a CICS VR function that removes all changes made to a particular VSAM data set by a specific batch job or a step in a batch job.
  2. Recovery Control data set (RCDS) are VSAM data sets that are a repository of the necessary information to create the job to recover VSAM data sets.

Changes needed to handle the situation

  • The batch job updates the recovered data through the RCDS which was allocated to CICS VR server address space
  • To backout the VSAM dataset, CICS VR batch backout job runs to retrieve the data from RCDS through DWWCONx DD statements.

We might encounter a situation where the RCDS are no longer available. In that case, we can execute Batch Backout by using the name of the MVS log (undo log stream as CVRTEST.UNDOLOG).

To run CICS VR batch backout when the RCDS are unavailable, complete the following additional tasks:

  • Remove the DWWCONx DD statements from the batch backout JCL.
  • Add the RCDS (NO) keyword to the BATCHBACK command. RCDS (NO) indicates that the RCDS are unavailable to CICS VR during this batch backout run.
  • Add the MVSLOG (undo log stream) command to the batch backout job. Undo log stream is the name of the undo log stream that was defined to CICS VR, when the batch job that made the updates that want to back out was originally run.

Note:  Specify the MVSLOG (undo log stream as CVRTEST.UNDOLOG) command to the batch backout job instead of RCDS.


Report of Batch backout data sets statistics

CICSVR - BATCH BACKOUT UTILITY                                        
                                                                                                                                   
 BATCH BACKOUT JOB STEP STATISTICS:                                                                                                  
 ----------------------------------                                                                                                  
                                                                                                                                     
 KEY TO FIELD IDENTIFIERS                                                                                                            
 -----------------------------------------------------------------                                                                   
 NO OF UNDOS FOR STEP - NUMBER OF UNDO RECORDS ENCOUNTERED FOR STEP                                                                  
 NO OF DATA SETS      - DIFFERENT DATA SETS UPDATED                                                                                  
 UPD-BEFORE           - DELETE OR UPDATE BEFORE IMAGE                                                                                
 ADD-BEFORE           - ADD BEFORE IMAGE                                                                                             
 ADDS                 - NUMBER OF ADDED RECORDS                                                                                      
 UPDATES              - NUMBER OF UPDATED RECORDS                                                                                    
 DELETES              - NUMBER OF DELETED RECORDS                                                                                    
 -----------------------------------------------------------------                                                                   
                                                                                                                                     
 JOB NAME: LOAD2                                                                                                                     
 JOB ID:   JOB02710                                                                                                                  
                                                                                                                                     
 NAME OF LOGSTREAM:                                                                                                                  
 CVRTEST.UNDOLOG                                                                                                                     
                                                                                                                                     
 JOB STEP  -NO OF -  -NO OF -  -- NUMBER OF BEFORE--   ---- NUMBER OF CHANGED -----   CHANGES                                        
   NAME     UNDOs      DATA      IMAGE LOG RECORDS           VSAM RECORDS             IGNORED                                        
           FOR STEP    SETS   UPD-BEFORE  ADD-BEFORE      ADDS    UPDATES    DELETES    BY EXIT                                        
 --------   --------  --------  ----------  ----------  ---------  --------  -------- --------                                       
                                                                                                                                     
 ADDREC2        4         1                    0                4                              0          0              4         0                                         
 --------   -          -------  --------             ----------       ----------                       --------     --------       --------   --------                                       
 LOAD2             5         1                   0                5                               0          0              5        0                                         
 --------             --------  --------             ----------       ----------                       ---------  --------          -------- --------                                       
 TOTAL             9         2                    0               9                               0          0               9        0                                         
 --------              --------  --------             ----------      ----------                       ---------  --------          -------- --------                                       
                                                                                                                                     
1CICSVR - BATCH BACKOUT UTILITY                                        DATE : 21/05/19     TIME : 19:54:01     PAGE : 2              
0                                                                                                                                    
 BATCH BACKOUT DATA SET STATISTICS                                                                                                   
 ---------------------------------                                                                                                   
                                                                                                                                     
 JOB NAME: LOAD2                                                                                                                     
 JOB ID:   JOB02710                                                                                                                  
                                                                                                                                     
 BASE NAME OF BACKED OUT DATA SET: CVTEST3.BLOG.KSDS1                                                                                
                                                                                                                                     
 BASE NAME OF ORIGINAL DATA SET: CVTEST3.BLOG.KSDS1                                                                                  
                                                                                                                                     
 FIRST AND LAST LOG RECORDS APPLIED:                                                                                                 
                                              DATE        TIME      TIME                                                             
    RECORDS                                   YYYY.MM.DD  HH:MM:SS  TYPE                                                             
    --------------------------------------    ----------  --------  -----                                                            
    LOG BLOCK TIME STAMP AT BACKOUT START     2021.05.19  19:51:24  LOCAL                                                            
    LOG BLOCK TIME STAMP AT BACKOUT END       2021.05.19  19:51:21  LOCAL                                                            
    --------------------------------------    ----------  --------  -----                                                            
                                                                                                                                     
 JOB STEP   ----- NUMBER OF BEFORE ---   ------- NUMBER OF CHANGED ------     CHANGES                                                
  NAME           IMAGE LOG RECORDS                 VSAM RECORDS               IGNORED                                                
                                                                                                                                     
             UPD-BEFORE     ADD-BEFORE        ADDS     UPDATES    DELETES     BY EXIT                                                
                     --------   -----------   ------------                    ---------  ----------  ---------   -----------                                              
 ADDREC2        0                 4                                  0           0          4             0                                              
                     --------   -----------   ------------                   ---------  ----------  ---------   -----------                                              
 LOAD2             0                 5                                  0           0          5             0                                              
                     --------   -----------   ------------                   ---------  ----------  ---------   -----------                                              
 TOTAL             0                 9                                  0           0          9             0                                              
                     --------   -----------   ------------                   ---------  ----------  ---------   -----------                                              
                                                                                                                                     
 -                    -------   -----------   ------------                   ---------  ----------  ---------   -----------                                              
 OVERALL                                                                                                                             
 TOTAL             0                  9                                   0           0          9             0                                              
                      --------   -----------   ------------                  ---------  ----------  ---------   -----------                                              
                                                                                                                                     
 BATCH BACKOUT EXIT ACTION STATISTICS                                                                                                
 ------------------------------------                                                                                                
                                                                                                                                     
 JOB NAME: LOAD2                                                                                                                     
 JOB ID:   JOB02710                                                                                                                  
                                                                                                                                     
                    :---------NUMBER OF -----------:                                                                                 
 EXIT NAME            RECORDS PASSED TO THE EXIT                                                                                     
 ------------------              ------------------------------                                                                                  
 ESDS DELETE                          0                                                                                              
 ------------------               ------------------------------      

This batch backout data set statistics report contains information about the type of updates that  superscript were backed out from each VSAM data set.

 

Drawback :

Executing CICS VR batch backout without the RCDS allocated causes,

  • Loss of Efficiency
  • Increased Processing Time
  • Less Error Checking

That is why RCDS is used by CICS VR batch backout to perform various error checking and improve performance.

 

 

Contact :

Dionne A Nerissa

QA Engineer – CICS VR

 

 

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