Removed hand over data in cluster singleton:
The support for passing data from previous singleton instance to new instance in a graceful leaving scenario has been removed. Valuable state should be persisted in durable storage instead, e.g. using akka-persistence.
http://doc.akka.io/docs/akka/2.3.0/project/migration-guide-2.2.x-2.3.x.html http://doc.akka.io/docs/akka/2.3.0/scala/persistence.html
Removed hand over data in cluster singleton: The support for passing data from previous singleton instance to new instance in a graceful leaving scenario has been removed. Valuable state should be persisted in durable storage instead, e.g. using akka-persistence.