Jack van Hoof wrote a post this week called "EDA versus CEP, Again..." and Joe McKendrick echoed his remarks in his post "Why 'Event Driven Architecture' is more than Complex Event Processing." Jack and Joe both suggest that CEP vendors are incorrectly trying to equate CEP with EDA. Jack's main point is that EDA is architecture, and CEP is a tool. My reaction was: "Well, of course that's true!" But what confuses me is exactly who Jack and Joe think is getting it wrong.
I got worried for a split second, because last summer I wrote a bunch of articles about EDA, event processing, and CEP. I wanted to make sure I hadn't been responsible for the confusion - so I went back and re-read my writing*** and I'm pretty sure Jack and I would agree on terms. Indeed, I often referred to Jack's thoughtful writing on the subject in those articles, and he commented on them.
But I think there's a point that wasn't covered by Joe and Jack - that CEP, in fact, is a really important element of an effective EDA. It's not a required element, but it sure makes it better. I believe that CEP will prove just as essential to EDA as a relational database is to client / server applications, or as application servers are to three-tier architecture. And it's a fair point that because it's becoming more common in mainstream IT, that more best practices, patterns, use cases, and discourse about effective EDA is needed.
Yet, as one of the posters in Jack's blog laments: "Why aren't more people talking about EDA, because that's what's really important?" Perhaps EDA isn't new, and CEP is. My first job out of school was as a developer working on an event driven trading system, in 1988. Our group built a multicast middleware driven, real-time trading system. The only other analagous software around was the Teknekron Information Bus, or TIB. We used Reuter's "new" digital market data feeds, and integrated that with event-driven trading screens and applications. It was an excellent event driven architecture. It was new. In 1988. We didn't use CEP because it didn't exist. Until recently.
And perhaps that's the point: maybe the reason why folks don't talk as much about EDA is that the disruptive element of EDA IS CEP?
*** Unfortunately Progress Apama has (I'm assuming mistakenly) attributed my writing to someboday named "Progress Apama," not the correct author: "Mark Palmer." Regardless, the articles to which I refer (e.g., "The Myths of EDA and SOA," and "The 10 Imperatives of Algo Trading") were written by me, and I stand by them.
