Bus Services—Mediation, Transformations, and Process Flows

The Service Bus provides critical integration handling capabilities en route to a service's execution from a requesting application or process. These mediation functions, provided for by intermediary components of the ESB, include protocol handling, routing, transformation, security, and management.

ESB services and bus functionality hover around this aspect of "document flows" in an organization, which in the ESB context can also be seen as a message flow. With ESB modeled on such flows, the information now flows as documents or messages rather than as procedure requests. With ESB now acting as an intermediary between the service requester and the service provider, additional infrastructure services are possible in this mode, while propagating the request to the service implementation. The infrastructure has clear "insight" into the message contents unlike simple P2P services interaction. This is useful in providing services such as routing, automatic transformation, security, quality of service assurances, etc. All of these can happen transparently, without interfering with the actual service's execution or imposing any additional programming requirements on the service.