Muttering About Rules and CEP
I read an excellent post by Paul Vincent, CEP vs. “Business Rules” where Paul does a super job summarizing the role of rules and rule-based systems for CEP. Paul mentioned his posts were motivated, in part, by Opher Etzion’s musings on rules.
In Bending CEP for Rules we discussed the same topic and there were some good comments and interaction, similar to the current discussions at Opher’s and Paul’s blogs.
The point of the matter is that rules have been over-stated in the CEP market, but for CEP to be successful in the long haul, software vendors must offer other analytics to end users, like Bayesian and Neural networks.
Rules-bases analytics are one important class of algorithms for event processing. However, for CEP to survive the test-of-time and become a viable stand-alone-technology class, software vendors must enhance their offerings so uses can easily plug in the event processing analytics then need.
In other words, software vendors should not unintentionally dictate the analytics and methods that users require for their event processing applications. Vendors should provide play-and-play analytical capabilities which permit users to solve a wide range of sophisticated event processing applications.
Today, unfortunately, almost all of the CEP vendors are promoting rule-based engines as their core analytical competency. Because of this situation, isn’t it only natural that there are mutterings about rules and CEP?
Opher replied to Paul’s note that, “CEP [and] Business rules [...] are conceptually orthogonal”.
When “orthogonal” is used as an adjective, it means “not pertinent to the matter under consideration.” I think that rules are very pertinent to event processing, so I’m not quite sure I would agree with Opher’s statement about rules and CEP being orthogonal.








Opher Etzion says:
Wednesday, October 24, 2007 at 7:02am
Tim – when I say “orthogonal” I mean “mutually independent”; Rules are programming style and CEP is “computing that performs operations on complex events”. Rules can be used for multiple purposes (among them CEP), and the “operations on complex events” can be performed in multiple ways (among them rules). Thus, these two terms are mutually independent, one does not need necessarily to use rules in order to define (or understand) CEP and vice versa.
Opher
Tim Bass says:
Wednesday, October 24, 2007 at 7:08am
Hi Opher,
Thank you for elaborating.
OBTW, great work on your blog. The event processing blogosphere is a much brighter place with your excellent blog posts.
Yours faithfully, Tim