IC67904: A TASK MIGHT RUN INDEFINITELY WHEN PH_TASK.TK_FREQUENCY IS SET TO '0 00:00:00'

APAR status

• Closed as program error.

Error description

• OAT allows to set the task frequency to '0 00:00:00' (in an
  effort to make the task a one-time one), but not to NULL.
  When the next execution time for such a task is calculated
  internally, the server falls in a loop of almost 10 millions
  iterations. The usual symptom is that one of the dbWorker
  threads stays in 'running' state for a long time, yielding from
  the CPUVP only sporadically. If you'll generate the stack of the
  particular CPUVP at that time (using 'onmode -X s <cpuvp_id>'),
  you'll see following stack trace:
  
  ph_update_execution_time
  do_task
  db_sch_worker
  udrlm_clang_execute_internal
  udrlm_clang_execute
  udrlm_exec_routine
  udr_execute
  dbsched_start_udr
  startup
  

Local fix

• Stop the dbScheduler, update the ph_task.tk_frequency column for
  particular task to NULL, start the dbScheduler
  

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * Users setting ph_task.tk                                     *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * ph_task.tk_frequency can be set '0 00:00:00'.                *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * Upgrade to IDS 11.50.xC8                                     *
  ****************************************************************
  

Problem conclusion

• The problem is first fixed in 11.50.xC8. Setting
  ph_task.tk_frequency to '0 00:00:00' will fail with a check
  constraint violation.
  

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:

Fix information

• Fixed component name

  IBM IDS ENTRP E

• Fixed component ID

  5724L2304

Applicable component levels

• RB15 PSY

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