PH41372: STOR SHORTAGE WHEN LOADING MANY TABLES RAPIDLY INTO ACCELERATOR WHEN USING IBM INTEGRATED SYNCHRONIZATION FOR INCREMENTAL UPDATE

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• Various error conditions may occur when running many loads of
  replicated tables into an accelerator in rapid sequence when
  using IBM Integrated Synchronization.
  A rapid sequence of multiple table load operations into an
  accelerator is identified by multiple pairs of messages
  DSNI090I STARTING ASYNCHRONOUS LOG READER TASK and
  DSNI092I NORMAL TERMINATION OF ASYNCHRONOUS LOG READER TASK
  in a very short time period, typically less than 30 seconds.
  
  Storage related errors may then be seen, e.g. one of but not
  limited to:
  ABND=04E-00E2001F in DSNIDLGR.DSNSVBK +02DAE
  ABND=0C4-00000038 in DSNIDM.DSNIOBDJ +040B6
  MSGDSNI091I ERROR IN ASYNCHRONOUS LOG READER TASK RC8 RC00C9000A
  
  When loading a replicated table into an accelerator ABND04E
  RC00D34454 with LOC=DSNLXLLM.DSNLJMLR:0005 may occur and will
  cause replication to be paused.
  
  Additional keywords:
  IDAAV7R5/K DATAGATE/K
  MSGDSNI090I MSGDSNI092I
  

Local fix

• n/a
  

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * All Db2 12 for z/OS users who either use                     *
  * IBM Db2 Analytics Accelerator with IBM                       *
  * Integrated Synchronization or IBM Db2 for                    *
  * z/OS Data Gate.                                              *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * Storage shortage when loading many                           *
  * tables in rapid sequence causing                             *
  * errors like but not limited to:                              *
  * ABEND0C4 RC00000038 DSNIDM.DSNIOBDJ                          *
  * OFFSET040B6, or ABEND04E RC00E2001F                          *
  * DSNIDLGR.DSNSVBK OFFSET02DAE. or                             *
  * MSGDSNI091I ERROR IN ASYNCHRONOUS LOG                        *
  * READER TASK RC8 RC00C9000A.                                  *
  * ABEND04E RC00D34454 with                                     *
  * LOC=DSNLXLLM.DSNLJMLR:0005 may occur                         *
  * when loading a replicated table and                          *
  * will cause replication to be paused.                         *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * Apply corrective PTF when available                          *
  ****************************************************************
  When loading a large number of tables into an accelerator or
  data gate instance in a very rapid sequence and reading from
  the log is slow it is possible that storage allocated by
  log reading tasks accumulates until storage is exhausted
  causing various error situations. A rapid sequence of log
  reading tasks being started and stopped by the load processes
  is identified by many pairs of messages DSNI090I STARTING
  ASYNCHRONOUS LOG READER TASK and DSNI092I NORMAL TERMINATION OF
  ASYNCHRONOUS LOG READER TASK in a very short time period,
  typically more than 20 pairs in less than 30 seconds.
  When the termination of a log reading task during a table load
  lasts longer than 10s due to very low processing priority,
  ABEND04E RC00D34454 can be issued by DSNLJMLR:0005. This abend
  may cause replication to go into paused state.
  

Problem conclusion

• The largest storage allocated by log reading tasks is
  deallocated while the termination request is processed to avoid
  accumulation of storage.
  When terminating a log reading task takes longer, any cleanup
  activity done by the watchdog process in parallel no longer
  causes a diagnostic abend in the termination routine.
  

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:

  UI78759

Modules/Macros

• DSNILGRT DSNLJMCF DSNILGWD DSNLJMLR DSNIOBDJ
  

Fix information

• Fixed component name

  DB2 OS/390 & Z/

• Fixed component ID

  5740XYR00

Applicable component levels

• RC10 PSY UI78759

     UP22/01/05 P F201

Fix is available

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