PK78320: IMS PA APPEARS TO GO INTO A LOOP, BUT IT IS ACTUALLY NOT A LOOP

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• An IMS PA job appears to go into a loop, but the job does run to
  completion after a few hours processing.
  It is a very large Pgm-switch chain of some 184K+ transactions
  which we keep and process sequentially when adding, updating and
  terminating transactions.  Because we don't actually get to a
  point where the transaction sequence is complete our CPU
  utilization just keeps growing (almost exponentially) each time
  we add a record to the chain.  Because we are using so much CPU
  traversing the chain and so few I/O in between times it looks
  like a loop.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All IMS Performance Analyzer V4.1 users.     *
  ****************************************************************
  * PROBLEM DESCRIPTION: IMS PA job appears to go into a loop,   *
  *                      but is actually not a loop.             *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  An IMS PA job appears to go into a loop, but the job does
  run to completion after a few hours processing.
  It is a very large Pgm-switch chain of some 184K+
  transactions which are kept and processed sequentially when
  adding, updating and terminating transactions.
  Because IMSPA doesn't actually get to a point where the
  transaction sequence is complete the CPU utilization just
  keeps growing (almost exponentially) each time a record
  is added to the chain.  Because the job is using so much CPU
  traversing the chain and so few I/O in between times
  it looks like a loop.
  

Problem conclusion

• Flush program switch entries from internal queue when
  queue exceeds 256 entries, and process later entries as
  new program switch sets tied to the originating transaction.
  

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:

  UK43708

Modules/Macros

• IPICPROC IPICXCPT IPIFPROC IPIGGET  IPIIPROC
  IPITDMGR IPITPROC IPI4DMGR IPI4PROC IPI4QMGR
  

Fix information

• Fixed component name

  IMS PERF ANALYZ

• Fixed component ID

  5655E1500

Applicable component levels

• R410 PSY UK43708

     UP09/02/06 P F902

Fix is available

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