PI41390: CICS WEBSERVICE TASKS BACK UP WAITING ON XMLOCK

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• Your CICS region appears hung.  CICS Webservice tasks including
  CWXN are in a LMQUEUE wait.   They are all backed up waiting on
  the XMLOCK.  The owner of the XMLOCK is gone from the system.
  The system is at maxtasks ( MXT ) and there is a flood of
  incoming work.  The work is arriving into CICS and getting
  attached and the tasks are all "fighting" to be dispatched.
  Unfortunately with the lock held, not much is going to happen
  until the one holding the lock is dispatched.
  This APAR is being taken to increase the priority of this task
  briefly ensuring that when the pop happens it will be the next
  task to get into the system given that the system is not short
  on storage (SOS).
  
  
  
  Additional Symptom(s) Search Keyword(s): KIXREVSWM
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All CICS Users.                              *
  ****************************************************************
  * PROBLEM DESCRIPTION: During workload tasks suspend on        *
  *                      XMLOCK during task termination.         *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  During a normal Task termination the task will acquire the
  XMLOCK.  If the system is at max tasks (MXT) then during
  termination the task will call DFHDSAT to attach the next
  available task.  When this attach is done the task with the
  XMLOCK may give up control and may not get control back
  straight away.  If there are other dispatchable tasks then they
  can get control before the original task.  This can lead a
  workload to slow because tasks need the XMLOCK in order to
  terminate.
  

Problem conclusion

• DFHDSAT has been updated to ensure that control is returned
  immediately to the task with the XMLOCK.
  

Temporary fix

• FIX AVAILABLE BY PTF ONLY
  

Comments

APAR Information

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

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

  UI30540

Modules/Macros

• DFHDSAT
  

Fix information

• Fixed component name

  CICS TS Z/OS V5

• Fixed component ID

  5655Y0400

Applicable component levels

• R900 PSY UI30540

     UP15/09/04 P F509

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.