PQ99716: OVERFLOW PROTECTION IMPROVEMENTS

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• Provide improvements to overflow protection.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: This APAR is for QCF users with local        *
  *                 messages queues. It can be installed , but   *
  *                 will have no impact on users with shared     *
  *                 messages queues.                             *
  *                 This APAR provides improved queue overflow   *
  *                 protection.                                  *
  ****************************************************************
  * PROBLEM DESCRIPTION: Overflow protection enhencment          *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  Overflow protection enhencment
  
        Main problem for queue overflow protection are the
  AIBREASN=A068 (UNLOAD LOCAL QUEUES, REQUESTED DESTINATION
  IS BEING READ BY ANOTHER TASK) errors returned on UNLOAD,
  which prevent the QSN BMP from successfully unloading a
  building up queue of commited messages.
    These messages are typically inserted from an application
  program (usually a BMP). The destination could be another
  transaction, LTERM or LU62 client.
     In all cases QCF/QSN BMP is activated successfully
  to locate the destination and unload the messages, but because
  destination's ITASK is also trying to process the messages,
  errors are returned to QCF. QCF skips the busy destination and
  unloads next destinations.In most cases this skipped destination
  is the destination, causing the build-up.
    New technique is developed within QCF to communicate with IMS
  and issue command to stop the destination from processing,so QCF
  could unload it.
  The communication between IMS and QCF is on XCF level. IMS Tools
  Online System Interface- which is part of QCF package -
  is used to support the communcation.
      In order to support communication between QCF and IMS system
  -new control statement-TOIPARMS-is added to IQCXCTRL control
  statements. TOIPARMS is used to identify the XCF group to be
  joined by QCF
  -new IMS PROCLIB member-FOI|imsid|P-is required for IMS syste
  to identify the group to be joined by IMS.
  
  Within the group (which should be the same for QCF and IMS)  QCF
  can send commands to IMS to stop destinations.
  
  FULL FORMAT OF TOIPARMS STATEMENT
  
  TOIPARMS XCFGROUP=TOIxxxxx
   When a A068 error is returned on UNLOAD, QCF uses the XCF group
  specified in the statement to join the group and request a stop
  command to be issued by IMS for current destination. The UNLOAD
  continues with the same destination.
  If the opperand is not supplied, no stop command will be issued.
  The unload will skip current destination.
  
  CUSTOMIZATIONS TO USE THE IMPROVED OVERFLOW PROTECTION
  
  A.CUSTOMIZATION FOR IMS:
  
    1.IMS Tools Online System Interface library has to be in IMS
    DFSRESLB conncatination.
    2.Memeber FOI|imsid|P  has to be created in library, reffered
    by PROCLIB DD of IMS start up JCL. Member's content:
    XCFGROUP=NAME1
      NAME1 - the last 5 characters of the group name. First 3
      chars are set to "TOI" The full group name will be created
      at IMS start.IMS will join the group at start up and issue
      messages:
      DFS0578I - READ SUCCESSFUL FOR DDNAME PROCLIB  MEMBER =
      FOIimsid  imsid
      FOI100I TOOLS ONLINE INTERFACE ENABLED, XCF GROUP=TOIname1
    For the full format of proclib member - see IMS Tools Online
    System Interface  User's Guide.
  
  B.CHANGES/ CUSTOMIZATION FOR QCF
    1.Sample JCL IQCPRCAB, IQCPRCBC, IQCPRCCD and IQCPRCUT are
    changed touse new program IQCRRC00 (preprocessor for DFSRRC00)
    2.Sample memebers with overflow protection control cards
    IQCQSNAB,IQCQSNBC,IQCQSBCD and IQCQSNUT are changed to include
    new QCF statements - TOIPARMS.
  
    3.Panel IQCP72A is changed to provide information for the new
    statement.
  
          Toiparms xcfgroup =  TOINAME1
  
   REQUIREMENTS FOR IMS:
   Next IMS APARs have to be installed:
   PQ97398 for IMS 7.1
   PQ96453 for IMS 8.1
   PQ97154 for IMS 9.1
  
   REQUIREMENTS FOR TOSI:
   Next APARs have to be installed:
   PK00125
   PK02706
  

Problem conclusion

• This APAR can be installed, but the new enhenced overflow
  protection will not be in effect if IMS and QCF customizations
  are not done. With the APAR installed and IMS proclib member
  missing, or overflow protection QCF procedures or members with
  control cards not changed - no errors will happen, no error
  messages will be issued, the enhenced protection will not be
  in effect.
  

Temporary fix

Comments

APAR Information

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

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

  UK08077

Modules/Macros

•    H0GN210J IQCH72A  IQCPRCAB IQCPRCBC IQCPRCCD
  IQCPRCUT IQCP7000 IQCP7100 IQCP7110 IQCP72A  IQCP7200 IQCP7210
  IQCP7220 IQCP7230 IQCQSNAB IQCQSNBC IQCQSNCD IQCQSNUT IQCQSNVS
  IQCRRC00 IQCUNLOD IQCXSUB6
  

Fix information

• Fixed component name

  IMS QUEUE CNTL

• Fixed component ID

  5697E9900

Applicable component levels

• R210 PSY UK08077

     UP05/10/14 P F510

Fix is available

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