Messaging GatewayMessaging MapperTransactional Client/ActorTransactional ClientTransactional ActorPolling ConsumerResource PollingEvent-Driven ConsumerCompeting ConsumersMessage DispatcherSelective ConsumerDurable SubscriberIdempotent ReceiverMessage De-duplicationDesign Messages with Identical ImpactState Transition Renders Duplicates HarmlessService ActivatorSummary