PH49727: IMPROVE MESSAGE DFHXQ0443

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• Customer suffered an outage because the list component of the
  sysplex CF structure was full.
  Usually, message DFHXQ0443 is used in order to trigger an
  automation process that cleans up the list data. This prevents
  such an outage.
  
  Message DFHXQ0443 wasn't issued in this case because the clean
  up process was already triggered 2 days ago. The number of lists
  in use (for big queues) was reduced by the automation, however
  not below of a 75% mark.
  There is a mechanism in CICS which sets a flag when DFHXQ0443 is
  issued, as there has to be some threshold before the message is
  to be reissued by a run of the server. Otherwise the message
  would get continually re-issued and flood the joblog.
  It is required therefore to ensure to delete enough big queues
  in order to drop below 75% mark, so that message DFHXQ0443 can
  be issued again.
  
  The message content has to be improved in order to describe this
  mechanism.
  

Local fix

• n/a
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All CICS users.                              *
  ****************************************************************
  * PROBLEM DESCRIPTION: Shared TS queue server did not reissue  *
  *                      message DFHXQ0443 to indicate Coupling  *
  *                      Facility structure full condition.      *
  ****************************************************************
  When all lists for large shared queues are used for TS
  queues and there is no space left for a new one, the shared TS
  queue server issues message DFHXQ0443 saying 'CF structure
  DFHXQLS_xxxx request failed, all lists are in use.'
  
  Clean up activity to delete large TS queues freed up some of the
  lists and list usage dropped below 75% of the total number of
  lists. However, when all the lists for the large queues were
  used up again, message DFHXQ0443 did not reissue to indicate CF
  structure full condition. This prevented further automated
  clean-up activity from being notified to take place.
  

Problem conclusion

• CICS has been changed to improve the message description, and to
  reissue the message DFHXQ0443 for subsequent failures if the
  number of list entries in use falls below 75% of the value
  specified by MAXQUEUES.
  
  The CICS Messages manual has been updated as follows. The System
  Action for message DFHXQ0443 has been updated to read "The
  failing request is given a NOSPACE indication if it originated
  from a CICS API request. This message will not be issued again
  for further failures while the shortage of list entries remains.
  The number of list entries in use needs to have fallen below 75%
  of the value specified by MAXQUEUES before the server will issue
  this message again for a further failure.
  

Temporary fix

Comments

APAR Information

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

  PH48567

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

  UI82885

Modules/Macros

• DFHXQCF
  

Fix information

• Fixed component name

  CICS TS Z/OS V6

• Fixed component ID

  5655YA100

Applicable component levels

• R400 PSY UI82885

     UP22/10/25 P F210

Fix is available

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