PH28761: IPI4PROC LOOP AFTER LABEL REC37 WHEN PROCESSING PROGRAM SWITCH TRANSACTIONS 20/08/25 PTF PECHANGE

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• 1. A tight loop is observed in routine IPI4PROC.REC37 when
  processing program-switch transactions. IMS Performance Analyzer
  expects only a single transaction associated with each
  Unit-Of-Recovery(UOR), whereas CMTMODE(MULT) transactions may
  result in multiple transactions for a single UOR. When these
  subsequent transactions for a UOR are associated with
  program-switch transactions, the chained transactions may
  not be handled correctly in processing the X'37' Syncpoint
  Message Transfer record(s), leading to unpredictable results,
  including a loop.  This tight loop hits only three instructions
  starting at x'538' past label REC37 or x'6304' past label
  IPIIPROC.
  2. An issue has been detected in the reporting of transactions
  that abended and have been re-enqueued from the SMB Suspend
  queue. Not all details of the initial transaction were
  cleared after reporting, leading to unpredictable results
  including duplicate transactions, mis-reported transactions
  and possible abends.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: Users of IMS Performance Analyzer V4.4       *
  ****************************************************************
  * PROBLEM DESCRIPTION: Loop during creation of a transaction   *
  *                      index                                   *
  ****************************************************************
  1. A tight loop is observed in routine IPI4PROC.REC37 when
     processing program-switch transactions. IMS Performance
     Analyzer expects only a single transaction associated with
     each Unit-Of-Recovery(UOR), whereas CMTMODE(MULT)
     transactions may result in multiple transactions for a
     single UOR. When these subsequent transactions for a UOR
     are associated with program-switch transactions, the
     chained transactions may not be handled correctly in
     processing the X'37' Syncpoint Message Transfer record(s),
     leading to unpredictable results, including a loop.
  
  2. An issue has been detected in the reporting of transactions
     that abended and have been re-enqueued from the SMB Suspend
     queue. Not all details of the initial transaction were
     cleared after reporting, leading to unpredictable results
     including duplicate transactions, mis-reported transactions
     and possible abends.
  

Problem conclusion

• 1. Message IPI0150E is still issued for a mismatched MSGORGTK,
     but a new IMS PA processing logic, PROGRAMSWITCH(OFF) is
     introduced. There is no user select-able option for
     PROGRAMSWITCH(OFF) it is generated automatically following
     the IPI0150E message. Message IPI0355W will be issued to
     indicate that a change in processing logic has taken place.
     With PROGRAMSWITCH(OFF), program-switch chains will not be
     be maintained and the X'37' Syncpoint Message Transfer
     record will not be processed to provide the SWITTIME field
     value, this will be reported as missing ('-') in form-based
     reports. The non-calculation of a SWITTIME value will also
     also impact on the calculation of the TOTALTM field value
     for program-switch transactions in form-based reports.
  
  2. Previously reported data fields, linked buffers and
     transaction completion levels are correctly reset for
     re-queued transactions previously reported as abended.
  

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:

  UI71347

Modules/Macros

• IPI4PROC IPIATRAC IPIGGET  IPIIPROC IPIMSGT  IPISAPAR
  

Fix information

• Fixed component name

  IMS PERF ANALYZ

• Fixed component ID

  5655E1500

Applicable component levels

• R440 PSY UI71347

     UP20/09/04 P F009 {

Fix is available

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