PI76549: WMQ 800: AN ABEND0C4 OCCURS IN CSQSCON2 WHEN MQ IS ATTEMPTING TOCONTRACT A PHB CONTAINING KEY8 SHB BLOCKS

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• ABN=0C4-00000004 may occur in CSQSCON2+00000D56 when the queue
  manager is attempting to contract a PHB containing key8 SHB
  control blocks.
  
  Additional Symptom(s) Search Keyword(s):
  ABEND0C4 ABENDS0C4 S0C4 S00C4 0C4 CSQSLD1
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users of WebSphere MQ for z/OS Version 8 *
  *                 Release 0 Modification 0.                    *
  ****************************************************************
  * PROBLEM DESCRIPTION: Abend 0C4 occurs in CSQSCON2 when       *
  *                      storage contraction occurs due to a     *
  *                      short on storage (SOS) condition, and   *
  *                      using Cluster Workload Exits.           *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  During storage contraction processing, CSQSCON2 attempted to
  free unused storage from MQ storage pools. After locating an
  empty SHB that had previously been used by a cluster workload
  exit, it tried to remove the empty SHB from the PHB chain. The
  SHB was in a different storage key, and so CSQSCON2 switched key
  before updating the previous SHB in the chain and set SHBNEXT
  to the new next element in the chain. However obtaining the new
  value required referencing working storage, which was fetch
  protected, causing the operation to abend 0C4.
  

Problem conclusion

• CSQSCON2 is changed to correctly update the chain of SHBs during
  storage contraction, when the SHBs are allocated using a
  different storage key.
  000Y
  CSQSCON2
  

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:

  PI77034 UI45209

Modules/Macros

• CSQSCON2
  

Fix information

• Fixed component name

  WMQ Z/OS 8

• Fixed component ID

  5655W9700

Applicable component levels

• R000 PSY UI45209

     UP17/04/08 P F704

Fix is available

• Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.