PK89948: REGION HANG MANY TASKS WAITING ON LMQUEUE LOCK MANAGER QUEUE

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• Region hang with many transactions in LMQUEUE waits.
  In the LM domain you see that the XSTLOCK is in use:
       USSLOCK/STLOCK/LD_GBLOCK     XSTLOCK
  .
    The lock may or may not show as owned by a task.
  The current task may not have requested the lock.
  An abandoned lock remains owned by the KE_NUM between tasks.
  If a new task is assigned to that slot, it would inherit
  ownership of the lock but not be aware of that.
  .
    The log will show an abend of some kind against one of the
  statistics modules.  So far, we have seen the following:
  .
  DFHAP0001 An abend (code 0C4/AKEA) has occurred
          at offset X'0E4A' in module DFHSTLK.
  DFHME0116
     (Module:DFHMEME) CICS symptom string for message DFHAP0001 is
     PIDS/5655M1500 LVLS/650 MS/DFHAP0001 RIDS/DFHSTLK
     PTFS/HCI6500 AB/S00C4 AB/UAKEA RIDS/DFHSTLK ADRS/00000E4A
  .
  DFHAP0001 An abend (code 0C4/AKEA) has occurred
          at offset X'0580' in module DFHSTTM.
  DFHME0116
     (Module:DFHMEME) CICS symptom string for message DFHAP0001 is
     PIDS/5697E9300 LVLS/630 MS/DFHAP0001 RIDS/DFHSTTM
     PTFS/HCI6300 AB/S00C4 AB/UAKEA RIDS/DFHSTTM ADRS/00000580
  .
    It may not matter which DFHSTxx program is involved.
  It may not matter which abend causes the task to be abended.
  What ever the source and cause of the abend, if the XSTLOCK
  is held at the time of the abend, it may not be released.
  Additional Symptom(s) Search Keyword(s):
  ABEND0C4 ABENDS0C4
  KIXREVDAM
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All.                                         *
  ****************************************************************
  * PROBLEM DESCRIPTION: CICS tasks are deadlocked waiting for   *
  *                      multiple locks, one of which is the     *
  *                      XSTLOCK.                                *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  A task was gathering statistics from various CICS domains. This
  drove the main statistics module DFHSTST which in turn called
  other statistics modules including DFHSTTM for Table Manager.
  DFHSTTM suffered an abend and its recovery routine was driven
  which issued message DFHAP0001. Control then returned to DFHSTST
  and STST_RESPONSE gets set to STST_EXCEPTION. DFHSTST obtains
  the XSTLOCK in preparation for calling the XSTOUT exit program.
  The lock was obtained successfully but DFHSTST checks
  STST_RESPONSE to determine if it has the lock. STST_RESPONSE is
  not STST_OK so DFHSTST exists without calling XSTOUT and without
  releasing the XSTLOCK.
  
  A subsequent task ends up waiting in the XSTLOCK which will
  never be released.  That task holds other domain locks.  This
  causes more tasks to hang and eventually the region has to be
  recycled.
  
  Additional keywords:
  SMLOCK
  

Problem conclusion

• DFHSTST has been modified to correctly determine if the XSTLOCK
  has been obtained.
  

Temporary fix

•             *********
              * HIPER *
              *********
  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:

  PK97270 UK50950

Modules/Macros

•    DFHSTST
  

Fix information

• Fixed component name

  CICSTS V3 Z/OS

• Fixed component ID

  5655M1500

Applicable component levels

• R500 PSY UK50950

     UP09/10/15 P F910

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.