PI32773: DEADLOCK IN MSIF, WHEN 2 TIMERS TRY TO ACCESS DNFO_TASK_SCHED AT THE SAME TIME

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• When DNF_O_CMD is deployed on 2 broker servers in a WBIFN
  Multi-Server environment, or deployed twice in a single server
  instance, deadlocks can occur on DNFO_TASK_SCHED, if a timer
  triggered action is initiated for both flows concurrently.
  The second trigger needs to be blocked in such a situation to
  avoid deadlocks.
  

Local fix

• N/A
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users                                    *
  ****************************************************************
  * PROBLEM DESCRIPTION: DEADLOCK IN MSIF, WHEN 2 TIMERS TRY TO  *
  *                      ACCESS DNFO_TASK_SCHED AT THE SAME TIME *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  In a multi-server environment the MSIF command flow DNF_O_CMD
  is typically deployed on each server. Each of these command
  flows automatically runs timer-triggered tasks like message
  timeout or cleanup processing.
  Formerly, it was possible that the timer-triggered tasks of
  the command flows run in parallel which randomly lead to
  DB2 deadlocks.
  

Problem conclusion

• Now, a new locking mechanism was introduced to prevent the
  timer-triggered tasks of multiple command flows to run in
  parallel.
  

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:

  PI32884

Modules/Macros

• DNF10056
  

Fix information

• Fixed component name

  MS FOR SN IA AN

• Fixed component ID

  5655FIN02

Applicable component levels

• R11F PSY UI26033

     UP15/03/24 P F503

Fix is available

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