II04390: VSAMINFO: BATCH LOCAL SHARED RESOURCE (BLSR) USAGE (REPOSITORY FOR VARIOUS USER ERRORS USING BLSR, ABEND16E)

APAR status

• Closed as canceled.

Error description

• THIS APAR IS TO ADDRESS COMMON ERRORS WITH BATCH LSR USAGE.
  ABEND16E - Usage errors:
    1. COBOL/VS PROGRAMS USING ISAM INTERFACE
       MANY OLD COBOL PROGRAMS WERE WRITTEN AS ISAM  PROGRAMS.  IF
       THE FILES WERE CONVERTED TO VSAM, THE PROGRAMS STILL WORK
       BECAUSE VSAM HAS AN ISAM INTERFACE THAT AUTOMATICALLY
       DETECTS AN OPEN OF AN ISAM DCB TO A VSAM FILE.  USE OF THE
       ISAM INTERFACE IS NOT ALLOWED WITH BATCH LSR.  THESE
       PROGRAMS WILL RECEIVE ABEND16E RC14 WHEN TRYING TO ACCESS
       ANY FILES WHICH ARE CODED IN THE COBOL/VS PROGRAM AS ISAM.
       TO DETERMINE IF THE ISAM INTERFACE IS BEING USED, THE COBOL
       SOURCE CODE MUST BE INSPECTED.  IF THE 'ASSIGN TO' CLAUSE
       ON THE 'SELECT' STATEMENT SPECIFIES 'I-DDNAME' THIS IS AN
       ISAM PROGRAM.  THE COBOL/VS MANUALS REFER TO THE 'I' AS AN
       ORGANIZATION INDICATOR.  THIS IS OMITTED FOR VSAM FILES.
       THESE PROGRAMS MUST BE CONVERTED IF BLSR IS TO BE USED WITH
       THEM.  TO SIMPLIFY CONVERSION, PROGRAM OFFERING 'COBOL AND
       CICS CONVERSION AID' (5785-ABJ) MAY BE USED.  THIS PROGRAM
       WILL CONVERT COBOL/VS PROGRAMS TO COBOL II AND ELIMINATE
       THE ISAM REFERENCES.  SINCE COBOL II DOES NOT ALLOW THE
       ISAM INTERFACE, COBOL II PROGRAMS CAN RUN WITH BLSR IF
       THESE NEWER COBOL II OPERATIONS COMPLY TO THE STANDARD
       BLSR OPERATIONAL CRITERION.
  
    2. PL/1 PROGRAMS WRITTEN FOR ISAM ACCESSING VSAM FILES
       PL/1 DOES NOT USE THE ISAM INTERFACE.  HOWEVER, IF THE
       'ENVIRONMENT' OPTION SPECIFIES 'INDEXED', IT DETERMINES
       WHETHER THE FILES ARE REALLY ISAM OR VSAM.  NATIVE VSAM
       SUPPORT IS USED FOR VSAM FILES, THE ISAM INTERFACE IS NOT
       USED.  BUT SPECIFYING BLSR IN THE SUBSYS PARAMETER IN THE
       JCL WILL PREVENT PL/1 FROM CORRECTLY DETERMINING WHETHER
       OR NOT THE FILES ARE VSAM, RESULTING IN THE ABEND16E-14
       BEING ISSUED.
          THE SOLUTION TO THIS PROBLEM IS TO CHANGE THE
       ENVIRONMENT  OPTION  FROM 'INDEXED' TO 'VSAM'.
  
  3. PROGRAMS USING RDJFCB TO IDENTIFY FILE TYPE:
        THE BLSR DOCUMENTATION CLEARLY STATES THAT USE OF IDCAMS
     WITH BLSR IS UNSUPPORTED.  THIS IS BECAUSE IDCAMS MAY
     CREATE ACBS ABOVE THE LINE.  SOME USERS HAVE TRIED TO USE
     IDCAMS REPRO AS A TEST WITH BLSR BUT THEN ENCOUNTER THE
     ABEND16E RSN14.  THERE IS NO CIRCUMVENTION, THIS IS NOT
     SUPPORTED.
  
  4. CROSS SYSTEMS PRODUCT ( CSP ) IS NOT SUPPORTED WITHIN THE
     BLSR ENVIRONMENT. CSP USES IDCAMS AND RECEIVES ABENDS16E
     IN FZEZSOPN.
       (SEE ALSO IBMINFO ITEM 44685 - DOCUMENT ID Q483541) ASKQ
  
  5. Use of batch LSR (BLSR batchlsr) to do sequential reads
     to a VSAM KSDS via its alternate index (AIX), followed by
     updates to the KSDS via the BASE index when UPGRADE (the
     default) is specified on the IDCAMS DEFINE ALTERNATEINDEX
     command, results in a WAIT when processing the VSAM data set.
     The UPGRADE can NOT complete because the sequential read
     request is holding the buffer.
        The same thing can happen if the application is doing both
     sequential reads and updates of a non-AIX file.  The sequen-
     tial request will hold position of the CI and an SVC1 will be
     issued by IDA019SE if the update needs the same CI.
        Therefore, a program that does both sequential processing
     and direct updates is not usually a candidate for BLSR simply
     because of the design differences of LSR processing.
  
     ADDITIONAL KEYWORDS: SVC1 HANG WAITING COBOL DEFERRED WAIT
                IDA019SE IDA019RY IDA019L1 IDADRQ ECBWAIT
  
  6. When using BLSR to access a dataset sequentially
     the application can appear to be in a loop.  This
     is due to the lack of  Implied Sequential Positioning
     when a dataset is accessed with LSR.  It is documented
     that the application must preposition the head to the
     first record.
  
  7.   Using BLSR with a TSO clist.  There is a VSAM LSR
    restriction where one can not use LSR (either coding the
    program to use LSR or by converting the program via BLSR)
    when multiple jobs are being called via a clist.
       For example, PGM A is called via a clist executed from an
    IKJEFT01 job. PGM A opens a dataset using LSR. PGM A then
    completes which causes task termination processing to run.
    Task termination issues a subpool freemain which frees all
    of the LSR buffers out from under VSAM.
       When PGM B is called from the clist it issues an open for
    the dataset causing VSAM to attempt to connect it to the
    freemained pools and control blocks. This usually results
    in an abend in VSAM open processing.
       This restriction should be documented fully in VSAM
    info apar II06620.
  

Local fix

Problem summary

Problem conclusion

Temporary fix

Comments

• FOR INFORMATION RELATED TO THE SETUP AND USE OF BLSR, SEE:
  MVS/ESA ADG Batch Local Shared Resources Subsystem : GC28167201
  

APAR Information

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• APAR is sysrouted TO one or more of the following:

Fix information

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