Explanation/Reference:
The Mediation Layer provides loose coupling for the entire architecture. It decouples the layers of the architecture as well as decoupling external users of the layers from the specific layers in the architecture.
The key capabilities in this layer include:
* Routing - Routing provides the ability to send the client request to the appropriate provider based on some criteria. The routing may even include sending the client request to multiple providers. This capability facilitates location transparency, versioning, scalability, partitioning, request pipelining, SLA management, etc.
* Protocol Mediation - Protocol mediation is the ability to handle a client request using one protocol (e.g.
WS*, JMS, REST) with a provider using a different protocol. This provides protocol decoupling between the provider and the consumer.
Message Transformation - Message transformation allows a client request using one message format to be handled by a provider that expects a different message format. This provides message format decoupling between the provider and the consumer.
* Discovery - Discovery is the mechanism by which a client finds a provider of a particular SOA Service.
Discovery can occur at design time or runtime.
* Monitoring - Monitoring captures runtime information about the messages flowing through the mediation layer. Since the mediation layer is an intermediary for message traffic, it provides a centralized monitoring capability.
* Policy Enforcement - Policy enforcement provides consistent application of policies (e.g. WS- SecurityPolicy) across all messages flowing through the mediation layer. Since the mediation layer is an intermediary for message traffic, it provides a centralized policy enforcement capability.
Reference: Oracle Reference Architecture, Service-Oriented Integration, Release 3.0