JR39834: A JOB THAT READS FROM A DATA SET AND USES A COPY STAGE TO DISTRIBUTE THE DATA TO MULTIPLE FUNNEL STAGES CAN HANG.

IBM InfoSphere Information Server, Version 8.5 Fix Pack 2

APAR status

• Closed as program error.

Error description

• A job that reads from multiple data sets and uses a copy stage
  to distribute the data from each data set to multiple funnel
  stages hangs intermittently.
  

Local fix

• The issue was originally reproduced when a 3 node configuration
  file was used for the job but if a single node or 2 node config
  file was specified we were able to run the job successfully.
  
  Enabling buffering for all the Funnel stage input links to force
  buffering for each "Input name" also resolves the issue even
  with a multi-node config.
  

Problem summary

• DataStage 8.5 parallel jobs which contain funnel stages can
  hang.
  

Problem conclusion

• Funnels can have multiple concurrent inputs which provide data
  at different and varying rates.  The funnel's inputs need to be
  buffered in order to prevent a deadlock condtion - which appears
  to the user as the job being hung (not making any progress).
  An environment variable named APT_NO_BUFFERING_FUNNEL_INPUT was
  added in an earlier, prior to the 8.5, release and if that
  variable was not set then the parallel engine would insert
  buffers in front of a funnel's inputs.  In the 8.5 release that
  environment variable and associated code were effectively (and
  unintentionally) made the default case - no buffers were being
  inserted for a funnel's inputs - and this could lead to
  deadlock.  The fix provided for this APAR makes buffer insertion
  (for funnel inputs) the default behavior again;
  APT_NO_BUFFERING_FUNNEL_INPUT must be set by the user if they
  want to prevent the buffering.
  

Temporary fix

• A user can explicitly define a buffer for each of funnel's
  inputs via the advanced tab on the Funnel stage in the DataStage
  Designer.
  

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

  WIS DATASTAGE

• Fixed component ID

  5724Q36DS

Applicable component levels

• R850 PSY

     UP