PH26611: LNMS TAKES CMAS DUMP DUE TO CTST BAD_TLST EXCEPTION

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• Some CMAS dumps are taken by LNMS task when system is in
  extremely bad CPU constraint.
  DUMP TITLE: EYU0XZPT DUMP,<jobname>,<cpsmname>,<sysid>,CMAS,
              LNMS,<taskid>,TRAC,EYU0CTST,<date>,<time>
  
  From the dump you can see the method causing the dump was
  CTST and the last exception trace was about Bad_TLST, which
  means that when CTST moves TLST to the buffer, something goes
  wrong.
  The problem is in the TLST serialization.
  

Local fix

• N/A
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All CICSPlex SM Users.                       *
  ****************************************************************
  * PROBLEM DESCRIPTION: A CICSPlex SM CMAS region issues        *
  *                      @EYUXZ0910I reporting a dump from       *
  *                      module EYU0CTST under an LNMS or LNCS   *
  *                      task.                                   *
  ****************************************************************
  * RECOMMENDATION: All CMAS regions must be restarted to        *
  *                 activate the fix. The restarts do not need   *
  *                 to occur at the same time.                   *
  ****************************************************************
  While attempting to transmit a message from one CMAS to
  another, module EYU0CTST detects an error in the format of
  a TLST style distribution list, and captures a dump.
  The TLST is expected to describe which CMAS the message should
  be transmitted to, but the storage at that location has been
  altered and is no longer valid.
  
  The message is being transmitted by a CMAS to CMAS Send Task
  (either LNMS or LNCS) on behalf of some other task. That task
  should hold a lock to protect the storage from being changed,
  but that lock has been released prematurely.
  
  The lock was released by a separate CMAS to CMAS Receive Task,
  either LNMI or LNCI. This task was attempting to form a new
  CMAS to CMAS connection to another CMAS, but was unable to as
  a prior connection to that same CMAS had not fully terminated.
  In this case, the receive task issues an exception trace entry,
  and attempts to release the lock. It is possible that this
  could release the lock, even though the lock is held on behalf
  of an unrelated operation by another task.
  
  The following exception trace entries would be written to the
  CMAS trace destination:
  CLMT XLOP LNMI COM Excp     28 ConExist
  CTMB CAMB XLNX COM Excp     12 EXCEPT
  CTST CLMS LNMS COM Excp     21 Bad_TLST
  
  This may occur when CMAS regions are starved of CPU resource.
  

Problem conclusion

• The CMAS to CMAS Initial Contact Transient modules,
  EYU0CLMT and EYU0CLCT, have been updated to ensure that
  method CPFL is only called to release the network topology
  lock in the case where the lock was requested by the currently
  running task.
  

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:

  UI74697 UI74698 UI74699 UI74700

Modules/Macros

• EYU0CLCT EYU0CLMT EYU0CPAC
  

Fix information

• Fixed component name

  CICS TS Z/OS V5

• Fixed component ID

  5655Y0400

Applicable component levels

• R00M PSY UI74700

     UP21/04/10 P F104

• R10M PSY UI74699

     UP21/04/07 P F104

• R20M PSY UI74698

     UP21/05/03 P F104

• R30M PSY UI74697

     UP21/05/03 P F104

Fix is available

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