JR35518: HEAP ALLOCATION FAILURE IN THE MQ CONNECTOR STAGE WHEN THE ROW BUFFER COUNT MESSAGE OPTION IS USED.

Download Fix Pack 2 for InfoSphere Information Server Version 8.1

APAR status

• Closed as program error.

Error description

• The MQ Connector stage can consume multiple input rows from a
  link, buffer them in memory, and then create a single output
  message with a payload of all the rows consumed. This feature is
  enabled by setting the row buffer count message option to -1.
  The problem is that the memory usage is extremely high when this
  feature is used.  Even small volumes of input data result in
  massive memory usage and ulimately heap allocation failures,
  similar to the following:
  
  Fatal Error: Throwing exception: APT_BadAlloc: Heap allocation
  failed.
  

Local fix

• The MQ Plugin stage (can be used in server or parallel jobs) is
  capable of similar (but more limited) functionality and does
  not have this problem.
  

Problem summary

• ****************************************************************
  USERS AFFECTED:
  MQ connector users with row buffer count set
  ****************************************************************
  PROBLEM DESCRIPTION:
  Job failed when row buffer count property set for MQ connector.
  
  There was a program error on the code path handling row buffer
  count property to concatenate multiple input data to create a
  message.
  There was a problem in the memory allocation logic, and memory
  leak occurred.
  When MQ connector runs handling the row buffer count, the osh
  process grows very rapidly up to 1-2 GB and then reaches limit
  and the job fails.
  
  ****************************************************************
  RECOMMENDATION:
  Apply the patch.
  ****************************************************************
  

Problem conclusion

• The code has been fixed to correctly free up the buffer. The
  allocation logic is enhanced as well to use the memory
  effectively.
  

Temporary fix

• Avoid using Row Buffer Count property and concatenate the data
  outside MQ connector.
  

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

Modules/Macros

• SERVER
  

Fix information

• Fixed component name

  WIS DATASTAGE

• Fixed component ID

  5724Q36DS

Applicable component levels

• R801 PSN

     UP