IT22281: CONCURRENTMODIFICATIONEXCEPTION THROWN WHEN MULTIPLE TCPIP CLIENT CONNECTIONS CREATED AT THE SAME TIME

APAR status

• Closed as program error.

Error description

• Logging code inside the makeConnections() method in the
  ClientConnectionManager class iterates through a HashMap
  containing the list of Connections outside of a Synchronized
  code block.
  This means that if a new connection is created at the same time
  as the logging then we throw the exception.
  
  
  
  
  
  
  
  Additional Symptom(s) Search
  Keyword(s):ConcurrentModificationException, TCPIP client,
  makeConnections() method, ClientConnectionManager class
  

Local fix

• Place the logging code inside a Synchronized code block.
  

Problem summary

• ****************************************************************
  USERS AFFECTED:
  All users of IBM Integration Bus enabling trace for TCPIP
  outbound client connections.
  
  
  Platforms affected:
  MultiPlatform, z/OS
  
  ****************************************************************
  PROBLEM DESCRIPTION:
  Concurrent TCPIP client connections to an external TCPIP server
  used the same tracing logic whilst creating each connection.
  
  This meant that if many client connections were created at the
  same time the tracing logic deadlocked.
  
  Synchronisation has been added to avoid this deadlock.
  

Problem conclusion

• Multiple concurrent TCPIP client connections can now be created
  at the same time whilst tracing is enabled.
  
  ---------------------------------------------------------------
  The fix is targeted for delivery in the following PTFs:
  
  Version    Maintenance Level
  v10.0      10.0.0.12
  
  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

  INTEGRATION BUS

• Fixed component ID

  5724J0540

Applicable component levels