BizTalk Server natively promotes an asynchronous messaging pattern and readily embraces an event-driven architecture. What BizTalk adds to the standalone WCF patterns we've seen earlier is the injection of a message broker. This middle layer loosely couples the enterprise systems on both ends of the service call while enabling a new set of messaging capabilities not available in standard service implementations.
Consuming asynchronous services from within BizTalk Server is an especially straightforward task. However, the huge caveat is that BizTalk Server 2013 cannot typically execute WCF services whose isOneWay flag is set to true. Wait, so doesn't that mean that BizTalk does not support asynchronous services? For me, it's a matter of perspective. BizTalk can still consume WCF services in an asynchronous manner from orchestration processes. Let's see how.
First, modify the existing IAdverseEventSync interface to...