PH23895: HUNG ACTIVE DISTSERV THREADS AFTER ASYNC LOG RDR TASK WAS ENDED BY TIMEOUT USING IBM DB2 ANALYTICS ACCELERATOR INTEGRATED SYNC

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• An asynchronous log reader task started for incremental updates
  for IBM DB2 Analytics Accelerator using Integrated
  Synchronization was terminated with DSNI092I TIMEOUT CAUSED
  TERMINATION OF ASYNCHRONOUS LOG READER TASK after a lock timeout
  DSNT376I on a needed resource. This could cause the distributed
  thread from the accelerator with
  WORKSTATION=Integrated-Synchronization to remain active until it
  is cancelled with the FORCE option. As long as the hung thread
  is not cancelled it will also prevent Db2 to be stopped
  successfully.
  IDAAV7R5/K
  

Local fix

• n/a
  

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * All Db2 12 for z/OS users who use IBM Db2                    *
  * Analytics Accelerator with Integrated                        *
  * Synchronization as replication method.                       *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * An asynchronous log reader task                              *
  * terminated with DSNI092I TIMEOUT                             *
  * CAUSED TERMINATION OF ASYNCHRONOUS LOG                       *
  * READER TASK after a lock timeout                             *
  * DSNT376I on a needed resource. This                          *
  * could leave the distributed thread                           *
  * suspended which also prevented Db2                           *
  * to be stopped successfully.                                  *
  * Asynchronous log reader tasks may show                       *
  * a delayed termination processing when                        *
  * the Db2 member is stopped.                                   *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * Apply corrective PTF when available                          *
  ****************************************************************
  When an asynchronous log reader task was terminating it tried
  to determine a log restart position which could run into a lock
  timeout. In that case the task was terminated by the watchdog
  process but the connection from IBM DB2 Analytics Accelerator
  identified by WORKSTATION=Integrated-Synchronization was never
  notified of the termination and the thread remained suspended.
  The thread had to be cancelled with the FORCE option before DB2
  could be stopped.
  Asynchronous log reader tasks were only terminating when the
  DBM1 address space was starting to terminate, which could see
  some delay after the -DB2 STOP DB2 command.
  Additional keywords: IDAAV7R5/K
  

Problem conclusion

• Code has been changed to avoid locks during termination
  processing of asynchronous log reader tasks and threads from
  IBM DB2 Analytics Accelerator will not be suspended to wait
  for termination of the asynchronous log reader task.
  Asynchronous log reader tasks will terminate immediately after
  the -DB2 STOP DB2 command has been issued.
  

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:

  UI69536

Modules/Macros

• DSNILGRT DSNLJEMG DSNLJMCF DSNILGWD DSNLJMLR DSNTDSTE
  

Fix information

• Fixed component name

  DB2 OS/390 & Z/

• Fixed component ID

  5740XYR00

Applicable component levels

• RC10 PSY UI69536

     UP20/05/23 P F005

Fix is available

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