PI72557: MQ ON ZOS: ALL CHINIT IN THE QUEUE SHARING GROUP MAY HANG WHEN A SHARED CHANNEL IS DELETED.

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• After deleting a shared channel receiver, the CHINIT no longer
  responds and CPU usage may be high.
  This problem may occur when there is a duplicate key in MQ table
  of DB2 data-sharing group.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * All users of IBM MQ for z/OS Version 9 Release 0             *
  * Modification 0.                                              *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * Increased CPU may be seen in the Channel initiator when      *
  * deleting a shared channel.                                   *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * When deleting a shared channel, the status is read from the  *
  * shared sync queue using a unique key for the channel stored  *
  * in DB2 table CSQ.ADMIN_B_SSKT. However, if multiple shared   *
  * channels have the same sync queue key due to some prior      *
  * error, the delete processing may enter a loop, with high cpu *
  * seen in the CHINIT address space, and the channel will not   *
  * be deleted. The CHINIT may become unresponsive, and require  *
  * it to be cancelled.                                          *
  ****************************************************************
  

Problem conclusion

• Delete processing has been altered to not enter a loop in this
  case, and allow the CHINIT to remain responsive.
  

Temporary fix

Comments

APAR Information

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

  PI64991

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

  UI43147

Modules/Macros

• CSQXRCMN
  

Fix information

• Fixed component name

  MQ Z/OS V9

• Fixed component ID

  5655MQ900

Applicable component levels

• R000 PSY UI43147

     UP17/01/10 P F701

Fix is available

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