Implementing Domain-Driven Design

Integration Using Messaging

A message-based approach to integration can allow any one system to achieve a higher degree of autonomy from systems it depends on. As long as the messaging infrastructure remains operational, messages can be sent and delivered even when any one system is unavailable.

One of the ways that DDD can be leveraged to make systems autonomous is through the use of Domain Events. When something of significance happens in one system, it produces an Event about it. There will tend to be several or even many such Events that occur in each system, and you will create a unique kind of Event as a means to record each. As Events occur, they are published to interested parties by means of a messaging mechanism. That’s just a big-picture ...