ConcurrentModificationException while replicating HTTP session in JBoss EAP

Issue

• An application in a clustered environment is throwing the following exception:

  [/<applicationName>] Failed to replicate session l2sojCF2w+jibsJcfvgN4A**.Node1
  java.util.ConcurrentModificationException
  ...
  

  ERROR [org.jboss.web.tomcat.service.session.JBossCacheService] externalizeSession(): exception occurred externalizing session SessionBasedClusteredSession[id: l2sojCF2w+jibsJcfvgN4A**.Node1 lastAccessedTime: 1274768963125 version: 2058 lastOutdated: 0]
  java.util.ConcurrentModificationException
  ...
  

  ERROR [CacheMarshaller300] Error while marshalling object: ReplicateCommand{cmds=PutDataMapCommand{fqn=/JSESSION/applicationName_localhost/l2sojCF2w+jibsJcfvgN4A**, dataVersion=null, data={0=171, 1=1326429207268, 3=org.jboss.ha.framework.server.SimpleCachableMarshalledValue{raw=java.util.HashMap@1759423663serialized=false}}, globalTransaction=null, erase=false}}
  ERROR [CommandAwareRpcDispatcher] java.util.ConcurrentModificationException
  ...