Same code throws java.io.NotSerializableException in one Websphere app server environment but not the other

Question

We encountered an interesting issue on our UAT WAS environment. The same code deployed to DEV (1 node) environment works perfectly. However, it throws the following exception on the UAT (2 nodes) with the same configurations. The only difference is the number of nodes. If any one has encountered this, please advise.

FFDC Exception:java.io.NotSerializableException SourceId:com.ibm.ws.session.store.db.DatabaseHashMap.commonSetup ProbeId:2052 Reporter:java.util.Hashtable@47a5b63a java.io.NotSerializableException: test.com.controller.myController

Env (DEV-1 node): WebSphere Platform 9.0.5.3 [BASE 9.0.5.3 f5032008.04] [JAVA8 8.0.6.7 ...] Env (UAT-2 nodes): WebSphere Platform 9.0.5.3 [BASE 9.0.5.3 f5032008.04] [JAVA8 8.0.6.7 ...]

Thanks in advance !

Answer 1

We found out the issue, it appears that a data model class and the super class of the controller were not implementing the serializable. Likely, some super class methods were called by the child controller causing this issue

Answer 2

Probably you have session persistence configured in your UAT2 environment, and your application is storing something not serializable in the http session. In UAT1 you have single server, so there is no need for session persistence in that case, hence no exception.