In a post Jack Van Hoof compared CEP and EDA and how they relate to an SOA. He said
CEP (Complex Event Processing) correlates multiple messages within given time frames. EDA is an architectural approach to model information systems from a business event perspective. EDA differs from SOA by its focus. SOA puts services at the center of the model and EDA does so with business events. The SOA-approach tends to result in a synchronous communication style and the EDA-approach in an asynchronous communication style.
He believes that the market does not understand EDA and explains how CEP is fundamentally different from EDA; that CEP is a tool and EDA is an architecture
CEP is not about business events by definition. CEP is a technique to process message streams. These messages do not need to represent business events. A business event is something that happens (change of state) where your business has planned to react upon in a predefined way. A business event is represented by a message, but not all messages are representations of business events. CEP is about messages, EDA is about business events. CEP can be used to implement EDA. You might say: EDA is CEP at the business level.
In response, Giles Nelson of Progress Apama, elaborated on the relationship with SOA, EDA and CEP with several key points. Joe McKendrick’s echoed a similar point of view in his post Why 'Event Driven Architecture' is more than Complex Event Processing. So also Udi Dahan, who illustrated, with a nice order-to-cash process example, how these concepts play together in a real world business problem. He summarized his position with the following remark
CEP, while being a challenging engineering field, and managing the technical risks around it necessary for a project to succeed in some circumstances, and really shines when used under the SOA/EDA umbrella, it should not be taken by itself and used at the topmost architectural levels.
Jack concludes his post with emphasis on the importance on EDA saying “I think EDA will definitely and radically change the way we currently look at business applications, including SOA”.
We have covered this debate in the past from an architecture perspective aswell. There appears to be a lot of confusion on how CEP, SOA and EDA relate to each other and its largely because of the vendors. It would be interesting to get a perspective on how these technologies are being adopted in the enterprise. What is the role of CEP in your enterprise? and how are they being used in EDA and SOA intiatives?