The CICS Connection VSAM FILE SHARING .BIM-VSHARE/VSE INSTALLATION AND OPERATIONS GUIDE Page 4 Introduction The Problem VSE/VSAM only permits two partitions to open a file for update

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  • (COPYRIGHT 1998, B I MOYLE ASSOCIATES, INC.)

    BIM-VSHARE is a proprietary product of B I Moyle Associates, Inc. It cannot bereproduced, changed, copied, or stored in any form (including, but not limited to, copieson magnetic media) without the express prior written permission of B I MoyleAssociates, Inc.

    B I M - V S H A R E / V S E"The CICS Connection"

    VSAM FILE SHARING PRODUCT

    INSTALLATIONAND

    OPERATIONS GUIDE

    Release 2.5

  • This documentation applies toRelease 2.5 of the program productBIM-VSHARE/VSE.

    Original Printing .................... 12/01/98Last Revised........................... 09/21/99

  • TABLE OF CONTENTS

    GETTING STARTED................................................................................................ 1Current Environment ......................................................................................................................3The Problem .....................................................................................................................................4Past Solutions....................................................................................................................................4How does a DBMS Solve the Problem? ......................................................................................5BIM-VSHARE......................................................................................................................................5Features ............................................................................................................................................6Ease of Use .......................................................................................................................................7About This Manual ..........................................................................................................................7New For This Release ......................................................................................................................8

    PROGRAMMERS GUIDE....................................................................................... 9Overview.........................................................................................................................................11BIM-VSHARE Architecture ............................................................................................................11A Sample BIM-VSHARE Execution ..............................................................................................12Steps to Define a Job to BIM-VSHARE .......................................................................................13Cross Memory Services Versus LU 6.2.........................................................................................14Not All the Files Have to Be Defined to CICS ...........................................................................14Accessing Files on a Different CPU ............................................................................................15VSAM File Security .........................................................................................................................15Running a Program in a Shared Environment .........................................................................15Recovery.........................................................................................................................................16Performance..................................................................................................................................16Problem Determination ...............................................................................................................16Assembler Support ........................................................................................................................17Non-Unique Keys With Alternate Index Files ............................................................................17Conclusion......................................................................................................................................18

    RECOVERY ......................................................................................................... 19Overview.........................................................................................................................................21Recovery In a Shared Environment ...........................................................................................21

    Is Delete, Define, Repro Practical For Recovery? ..............................................................21Who Else Can Update My Record? ......................................................................................21How Long Should I Lock a Record? ......................................................................................21What Happens If My Program Abends? ..............................................................................22

    Locking and Releasing Records Within CICS...........................................................................22Multiple Programs Updating the Same Record..................................................................22

    BIM-VSHARE 3 Tiers of Recovery .................................................................................................24Tier 1: No Syncpointing.................................................................................................................25

    What is Tier 1? ............................................................................................................................25What Type of Job Should Use Tier 1? ....................................................................................25How is Tier 1 Implemented?....................................................................................................25How Are the Files Recovered After an Abend? .................................................................26

    Tier 2: Implied Syncpointing ........................................................................................................27What is Tier 2? ............................................................................................................................27What Type of Job Should Use Tier 2? ....................................................................................27How is Tier 2 Implemented?....................................................................................................27What is Journaling? ..................................................................................................................27Why Use Journaling?................................................................................................................28What is Backward Recovery? ................................................................................................28Journaling and Recovery with Tier 2.....................................................................................28

  • TABLE OF CONTENTS

    Journaling Example with Tier 2............................................................................................... 28The Steps in the Tier 2 Recovery Process.............................................................................. 29Define the Job to Utilize Journaling ...................................................................................... 30Define the Syncpoint Level .................................................................................................... 30Create a BIM-VSHARE Recovery Procedure....................................................................... 31Creating BIM-VSHARE Recovery Parameters...................................................................... 31What is Journaled and What is not Journaled? ................................................................. 32Recovery Example................................................................................................................... 32

    Tier 3: Explicit Syncpointing ......................................................................................................... 33What is Tier 3?............................................................................................................................ 33What Type of Job Should Use Tier 3?.................................................................................... 33How is Tier 3 Implemented? ................................................................................................... 33Determine If BIM-VSHARE Journaling is Required............................................................... 33Modify The Program to Issue the Syncpoints or Rollbacks ............................................... 34Batch-Only Mode..................................................................................................................... 34Requesting a Syncpoint or Rollback .................................................................................... 34Sample Syncpoint Request .................................................................................................... 34Issuing Syncpoints and Rollbacks Through A Batch Exit Program................................... 36Syncpoint and Rollback Journal Records ........................................................................... 38Create an Application Recovery Scheme ......................................................................... 39Tier 3 Recovery Scenario......................................................................................................... 39Recovery and ESDS Datasets................................................................................................. 40

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