Implementation of ESB. An ESB is constructed around the routing and transformation routines implementing the message bus and canonical data model pattern among other key SOA patterns. This is exemplified in fig 3.2.4Errore. L'origine riferimento non è stata trovata.. The routing and transformation routines are controlled by a set of configuration components. Among these components are a service registry, shared security component, a service management component and the service orchestration component that set the routines for a specific type of event or message in the routing and transformation. These components are controlled trough an ESB administration application. The ESB is used by subsystems and their applications. Modern systems are typically prepared for a service oriented architecture by communicating with the ESB trough service interfaces. This without any specific adaption. Legacy and specialized subsystems as well as applications, require adapters to communicate through the ESB. An adapter provides the conversion of messages/information from/to the ESB. Some specialized applications will not benefit from working through the ESB. For example administration applications of a subsystem.
