As a request travels between service requesters and
providers, logic that controls what happens to it and how it is routed (often
known as the mediating or service interaction logic) can be inserted. This
mediating logic is performed by mediation modules, which are
made up of imports, exports, and flow components
- Imports
- Imports let the mediation module reference external services as if they
were local services.
- Exports
- Exports expose a mediation module’s external interfaces (or access points)
to a client who wishes to use a function of the module as a service.
- Flow components
- Flow components can carry out the service integration logic, including:
- Routing
- Database lookup
- Database logging
- Structure transformation
Figure 1. A mediation module is a type of SCA module for service requests
over an enterprise service bus.
A mediation module acts on the flow of service requests between requesters
and providers.
Often, it is efficient for a mediation module to reuse an existing module
by linking the relevant imports and exports.
Figure 2. A mediation module forwarding request messages to another mediation
module.
This technique enables more powerful and flexible mediation
of service requests flowing over the enterprise service bus.
The mediation modules are developed in a separate tooling environment and
are deployed to the run time environment.