PI13189: The Gateway daemon throws a ConcurrentModificationException when an IPIC connection fails to connect

CICS Transaction Gateway Desktop Edition V9.1
CICS Transaction Gateway for Multiplatforms V9.1 (all supported platforms)
CICS Transaction Gateway for Multiplatforms V9.0 (all supported platforms)
CICS Transaction Gateway Desktop Edition V9.0 (all supported platforms)
CICS Transaction Gateway for Multiplatforms V9.0 Fix Pack 4
CICS Transaction Gateway Desktop Edition V9.0 Fix Pack 4
CICS Transaction Gateway for Multiplatforms V9.0 Fix Pack 5
CICS Transaction Gateway Desktop Edition V9.0 Fix Pack 5

APAR status

• Closed as program error.

Error description

• The following message is written to the CICS TG log and
  requests are not sent to the CICS server:
  CTG8433E Connection failure for IPIC connection to CICS server
  <CICS_server_name> reason = java.io.IOException: Already
  connected.
  
  A ConcurrentModificationException is reported: Exception in
  thread "Receiver-<URL>:<Port>(n)"
  java.util.ConcurrentModificationException at
  java.util.Vector$Itr.checkForComodification(Vector.java:1167) at
  java.util.Vector$Itr.next(Vector.java:1144) at
  com.ibm.ctg.server.isc.SessionPool.close(Unknown Source) at
  com.ibm.ctg.server.isc.Connection.closeSocket(Unknown Source)
  at com.ibm.ctg.server.isc.Connection.close(Unknown Source) at
  com.ibm.ctg.server.isc.Connection.connectionError(Unknown Source
  at com.ibm.ctg.server.isc.Receiver.run(Unknown Source) at
  java.lang.Thread.run(Thread.java:780)
  
  Additional search words msgCTG8433E msgCTG8433 CTG8433
  

Local fix

• No work-around, fix required.
  

Problem summary

• ****************************************************************
  USERS AFFECTED:
  All users of IPIC-connected CICS servers
  ****************************************************************
  PROBLEM SUMMARY:
  When an IPIC connection can not be established, the sessions
  for the IPIC connection are terminated. The Gateway daemon
  throws a ConcurrentModificationException if the session
  termination occurs before the session initialization has
  completed. The Gateway daemon does not terminate. Further
  attempts to connect to the CICS server fail.
  ****************************************************************
  

Problem conclusion

• CICS TG has been corrected and will not throw the reported
  ConcurrentModificationException when a connection attempt
  fails.
  

Temporary fix

Comments

APAR Information

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

  PI06947

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

Fix information

• Fixed component name

  CICS TRNS GATE

• Fixed component ID

  5724I8103

Applicable component levels

• R900 PSY

     UP