PH20179: SIMULTANEOUS CREATION OF PARSERS IN TWO DIFFERENT SHARED ROW VARIABLES COULD CAUSE CORRUPTION.

APAR status

• Closed as program error.

Error description

• If a message flow has multiple SHARED ROW variables then each
  of these
  will have its own separate root parser based on the
  single
  RowVariablesMessageGroup message group. While the
  operation of each shared
  row variable is independent in terms
  of syntax elements etc, a request to
  create a new parser in the
  SHARED ROW tree will go to the Message group on
  which they are
  based. The Message Group createParser call will scan its
  list
  of parsers and allocate an existing unused one if it exists. If
  one
  does not exist, then a new parser will be created and added
  to the list.
  
  The manipulation of SHARED ROW variables is
  usually protected by Atomic
  blocks. However, when using two
  different ROW variables it would be
  possible to use different
  scoped ATOMIC blocks for different ROW variables.
  For this
  reason it would be possible for different message flow
  instance
  threads to cause a parser creation in two different
  ROW variables but would
  both use the same
  RowVariablesMessageGroup. As these operations are not
  locked,
  it would be possible for both to given the same free parser or
  one
  to corrupt the parser list for the other.
  

Local fix

Problem summary

• ****************************************************************
  USERS AFFECTED:
  All users of IBM Integration Bus 10.0 and App Connect Enterprise
  11.0 using multiple SHARED ROW variables.
  
  
  Platforms affected:
  z/OS, MultiPlatform
  
  ****************************************************************
  PROBLEM DESCRIPTION:
  An Integration Server may start using excessive CPU that
  continues even when the message flows are no longer processing
  messages. There is a very small possibility when using multiple
  SHARED ROW variables, for corruption to one of the variables
  message trees to occur, resulting in a CPU loop whilst parsing
  the tree.
  

Problem conclusion

• The product has been modified to prevent the CPU loop as a
  result of the corrupted SHARED ROW variable message tree.
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
  Version    Maintenance Level
  v10.0      10.0.0.20
  v11.0      11.0.0.7
  
  The latest available maintenance can be obtained from:
  http://www-01.ibm.com/support/docview.wss?rs=849&uid=swg27006041
  
  If the maintenance level is not yet available,information on
  its planned availability can be found on:
  http://www-1.ibm.com/support/docview.wss?rs=849&uid=swg27006308
  ---------------------------------------------------------------
  

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

  IIB Z/OS

• Fixed component ID

  5655AB100

Applicable component levels