Spring will append sessionid to destination queue for external message broker like RabbitMQ. I noticed this sessionId for username is fetched from DefaultUserSessionRegistry ->userSessionIds.
Will it work in cluster environment? If it is not being fetched from DefaultUserSessionRegistry, where is this mapping stored?
You're right, in a clustered environment, this may not fully work at the moment.
You probably want to track the SPR-11620 issue, targeted for Spring Framework 4.2.