PM05524: IN TRYING TO DELETE A HUGE AMOUNT OF MESSAGES, IMS APPEARS TO GOINTO A LOOP DUE TO EXCESSIVE ECSA CONSUMPTION

Obtain the fix for this APAR.

APAR status

• Closed as unreproducible in next release.

Error description

• QCF is reading many, many, messages from the shared queue
  and very few of which match the delete criteria.
  No release is done for these messages until the end of the QCF
  process. This caused the ECSA exhaustion problem.
  A /ERE is attempted which also fails with either:
  ABENDU0078 ABENDU0070 ABENDU0718
  due to the ECSA not being cleaned up.
  
  The cause is QCF Unload criteria which matches few messages but
  require a very large number of messages to be examined.
  
  This happens only with QCF3.1 UNLOAD and if there is a huge
  amount of messages on one destination.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All QCF V3.1 users                           *
  ****************************************************************
  * PROBLEM DESCRIPTION: If there is huge amount of messages on  *
  *                      one destination. These are read with    *
  *                      GU and not release till the end of the  *
  *                      destination. There is a problem with    *
  *                      ECSA consumption and it causes an IMS   *
  *                      abend and restart failure.              *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  If there is huge amount of messages on one destination. There is
   a problem with ECSA consumption and it causes an IMS abend and
  restart failure.
  

Problem conclusion

Temporary fix

Comments

• Now the QCF will monitor the usage of ECSA. When a critical usag
  e (threshold) has been reached, and before the ECSA storage is e
  xhausted, QCF will terminate the function. The function will be
  treated as if unload has completed. QCF will issue an informatio
  nal message stating that the function has been terminated early
  and will be treated as though the function completed successfull
  y. QCF will return a Return/Reason code indicating that the func
  tion completed early with information that usage of ECSA forced
  early termination. The customer should consider that a minimum o
  f 200 bytes of ECSA will be required for each message in the Sha
  red Queues that will be read, to satisfy the QCF function.
  

APAR Information

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

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

  UK60618

Modules/Macros

• IQCBROWS IQCF0COD IQCF0CTR IQCLOAD0 IQCLOD61
  IQCMRAEQ IQCMRQWK IQCQMR1A IQCQMR1B IQCQMR1X IQCQMR18 IQCQMR19
  IQCQMR5A IQCQMR5B IQCQMR5X IQCQMR58 IQCQMR59 IQCRECOV IQCUNLOD
  IQCXCMD6 IQCXCTRL IQCXGUN6 IQCXREAD IQCXRPF0 IQCXSVF0
  

Fix information

• Fixed component name

  IMS QUEUE CNTL

• Fixed component ID

  5697E9900

Applicable component levels

• R310 PSY UK60618

     UP10/09/22 P F009

Fix is available

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