PI82787: CICS REMAINS SOS AFTER MESSAGE DFHSM0133 FOR UPTO AN HOUR UNTIL DFHSM0134 IS ISSUED BUT PROCESSES OK.

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• Env: CICS TS 5.1
  Customer has a CICS region that sometimes goes into an SOS
       situation and it takes a LONG time to recover from it. Last
       Thursday it was in SOS since 09.32.02 till 10:19:09, but no
       task was suspended in EDSA and everything was working fine.
  09:32:02 DFHSM0133 CICS is under stress (short on storage above
                                           16MB).
  10:19:09 DFHSM0134 CICS is no longer short on storage above
  16MB.
  .
  This problem is intermittent and only seems to occur at times
  when an application task running on an L8 TCB issues a CICS
  GETMAIN for 120M which gets suspended and then is purged by
  DTIMOUT mechanism after one minute.
  Storage seems to be available once this task is terminated
  but CICS does not turn off the SOS flag and issue DFHSM0134
  until a second task causes issues another large GETMAIN and
  gets suspended for insufficient storage and the DTIMOUT
  kicks in to pureg/abend this task.
  After that processing we see DFHSM0134 issued.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All CICS Users.                              *
  ****************************************************************
  * PROBLEM DESCRIPTION: CICS region goes short on storage above *
  *                      the line and issues message DFHSM0133.  *
  *                      The CICS region continues running       *
  *                      normally even though message DFHSM0134  *
  *                      is not issued when CICS is no longer    *
  *                      short on storage.                       *
  ****************************************************************
  * RECOMMENDATION: .                                            *
  ****************************************************************
  A CICS regions goes short on storage above the line and issues
  the SOS message DFHSM0133.If the task that caused the SOS
  condition be resumed, because of a time out just as DFHSMSY is
  also resumed, then DFHSMSY will believe that CICS is still SOS
  and not issue message DFHSM0134.
  The CICS region runs normally.
  Message DFHSM0134 will be issued when the CICS region suffers
  another SOS condition.
  
  Keywords: msgDFHSM0133 msgDFHSM0134 SM0133 SM0134 0133 0134
  

Problem conclusion

• DFHSMSY has been changed to check the pagepools for SOS when
  each transaction is resumed which frees up storage.
  

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:

  UI48797 UI48798 UI48799 UI48800

Modules/Macros

• DFHSMSY
  

Fix information

• Fixed component name

  CICS TS Z/OS V5

• Fixed component ID

  5655Y0400

Applicable component levels

• R000 PSY UI48798

     UP17/07/21 P F707

• R100 PSY UI48800

     UP17/07/22 P F707

• R800 PSY UI48797

     UP17/07/20 P F707

• R900 PSY UI48799

     UP17/07/20 P F707

Fix is available

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