Interestingly, CEP is Not BPM, BAM, BRE, BRMS or SOA stimulated many great comments and the rebuttal Smart Order Routing and CEP - Made for Each Other.  James Taylor responded with Business rules, decisions and events.   I followed up with CEP is Not Low Latency Messaging, EAI or ESB and James replied in turn with Still More on Event Processing.  It’s great to see the blogosphere doing so well.  Continuing, I would like to discuss smart order routing (SOR) a bit more and why routing is not CEP.

First of all, let’s ground the discussion a bit by translating “smart order routing” to “rule-based message routing” since in this application “smart”  translates to “using rules” and “order” translates to “message”.    Basically, Mark (and other “new on the routing scene” stream processing players) argue that rule-based message routing is CEP.  I will argue that routing is not even close to CEP.  Here is why,

Let’s take a look at a router on the backbone of the global Internet.   A backbone router has very sophisticated software developed over many decades.   These routers run sophisticated, mature algorithms to determine how to route messages (packets) and use these algorithms to build complex routing tables. 

In addition, these routers process messages (packets) from countless sources and route messages (packets) to countless destinations.  Using some of the terms in early posts (above), there is a great “confluence of events” processed by routers.    Futhermore, there are normally quite complex authentication, authorization and other security parameters managed in a router, all in real time.   Routers do much more, but I don’t want to get too deep into routing in this post.

My point is that, without any doubt, global Internet routers process very “cloudy” “confluence of events” with much more sophistication than order routing applications.    However, we do not call Internet routing “CEP”, regardless of how many connections are processed or how much sophisticated processing occurs.  The reason is because the “C” in “CEP” defines a complexity that is at a higher abstraction than messaging and routing.

If you study the literature on CEP, some of which I posted recently, CEP was envisioned to solve complex event processing problems “on top of the routing layer” because the routing layer is a mature technology layer.  We can route, pure and simple.  Of course, we are always seeking faster, more scaleable and more secure routing. 

I admire some of the startups in the CEP/ESP/EP space for working hard to make money and for aggressively positioning their products and attempting to build market share.   However, issues surface when these same companies seem to believe they are the first companies to work in the event processing or message routing space and that they can define whatever they want as “complex event processing” as long as it benefits their sales targets.

There is no doubt that a router does much more sophisticated event processing than the new rule-based stream processing systems running continuous queries across streaming data.  There is no doubt that a router processes a complex “confluence of events”.   However, we don’t call routers “CEP”. 

We do not call routers “CEP” because CEP is about a higher level of knowledge processing.  CEP was created to detect the “complex events” that happen above the mediation and routing layer.     The literature and original examples on CEP are quite clear on this.