Are ESB gateways and adapters (when running in JBoss AS) 'cluster aware'? I don't mean cluster capabilities given by the application server (JMS, Session Beans and so on), but the ESB components itself.
What happens when ESB is deployed on all nodes within the cluster and there is a FTP gateway where
That option refers to a single gateway instance. At the moment the inbuilt clustering approach for the ESB assumes stateless and idempotent services. If you want to impose ordering across a number of concurrent listeners/gateways then you can always develop your own. Currently there is no form of cooperation between multiple instances of service supported by the ESB.