Figure 9: Internal and external API hub
The internal API-hub is responsible to provide access to internal consumers.
The external API hub is intended to facilitate synchronous traffic across the enterprise boundaries. It exposes a specific part API services to external parties, with additional security measures and policies. A second function is to access external API-s, e.g. provided by B2B-partners or other commercial or governance organizations. It may take care of all security and other policies and make the allowed external API available on the internal API-hub for internal consumers.
Note that multiple instances of the API Hub may be used to support different service levels, e.g. for critical and less critical API-s.
Where EAC-s are responsible for local functionality and local work-processes does the Process Hub support end-to-end processes that cross functional borders. As the Process Hub may depend on multiple EAC-s these processes themselves depend on the availability of the EAC-s. Process logic can simply be short-lived orchestrations, but also complex end-to-end Business Process Management (BPM) processes, or Adaptive Case Management (ACM) cases. Integration 2.0 adopts this principle through the Process Hub: a component responsible for running any type of process mentioned above. The process hub does not access EA components directly. It requests data or triggers transaction only through the API hub. This way the processes remain stateless and agnostic which EAC-s provide the required logic.