Hi All, I was recently working with the $subject. I used two different tomcat instances to create the cluster. But i was facing the same problem as mentioned in here [1]. I digged in to see the root cause for this and found that the ClusteringAgent (TribesClusteringAgent) was never initialized and this was causing the NPE in DefaultStateManager. This was because, by default, the parameter "AvoidInitiation" is set as "true" under the clustering section in axis2.xml. So when running axis2 on tomcat, this skips the initiation of the cluster when the ConfigurationContext is being build. This issue can be overcome by setting the parameter as "false". The other place where the cluster initialization is called, is in AxisServer. This will not be called when running axis2 as a webapp.
Thanks, Kishanthan. [1] https://issues.apache.org/jira/browse/AXIS2-5178
