The Grammar of Complex and Intelligent Events

June 28, 2008

Folks defining CEP, and now this new term IEP, have been very passionate over the past few years that “Complex Event Processing” means the Processing of “Complex Events” not the “Complex Processing” of Events.   

Grammatically speaking, it follows that Complex is an adjective describing a noun, Event; and Processing is a verb. 

Complex events are defined by the same community as composite events, or events that are composed of two or more “contributing” events.

To be consistent, I think we should follow the same logic and grammar in the discussion of “Intelligent Event Processing”. 

It follows that Intelligent should be an adjective describing a noun, Event; and Processing is a verb.  It also follows that “Intelligent Event Processing” means the Processing of “Intelligent Events” not the “Intelligent Processing” of Events.   

This is precisely the problem that folks are creating a new CEP term, “Intelligent Event Processing” to describe processing capabilitities that are missing from the current suite of self-described CEP software products.   What people really mean to describe is the Intelligent Processing of Complex Events.   However, based on the same grammer used in defining CEP, they have created the Processing of Intelligent Events.

The use of inconsistent grammar and logic is not good for the CEP community, in my opinion.   Just because the current generation of self-described CEP vendors do not rise to the capability required by the vast majority of business event applications, we should not create new terms just to make marketing folks happy.

I think I am in a good position to speak about this, because some of my best friends work for software companies selling self-described CEP software and they have seemingly lost patience  because I refuse to support inconsistent illogical positioning and repositioning of the CEP market.

Why is the grammar between the terms “Complex Event Processing” and “Intelligent Event Processing” inconsistent?.   Folks can only spin and reposition CEP so much before all the spin, hype, and repositioning begins to catch up with the community.   

Dr. David Luckham’s original papers and single book on CEP was clear enough about CEP; and CEP covers the entire space that Opher Etzion would like to reposition as IEP.    The Grammar of Complex and Intelligent Events are, at best, misleading and inconsistent.

I think the main problem is that what Opher has been describing is the Intelligent Processing of Complex Events – however, to say this would affirm what I have been evangelizing for over two years.

On Elephants and Analytics

June 26, 2008

In On EP and Analytics, good friend and respected colleague Opher Etzion applies the well known metaphor of the big elephant to describe how, if you are observing certain specific domains of a subject, like fraud detection, then your view of the whole elephant is biased by your lack of perspective of the entire big elephant.

I am pleased that dear Opher continues to use this metaphor in counterpoint because the same metaphor can be used to describe the carefully selected group of vendors that have banded together to called themselves CEP Vendors.  This group, many founding members of the EPTS, have formed a merry band of well-intended event processing “specialists” and the same lovely elephant causes this group of bonded colleagues to make elephant-blinded statements, as Opher has made in his quoted post:

“Currently most CEP applications do not require analytics.” 

The reason, I believe, that Opher makes the statement above is because the group of software vendors calling themselves “CEP vendors” represent a very small part of the overall event processing elephant;  and hence, since these self-described CEP applications appear to require very little or no analytics, then, by the same logic, CEP requires no analytics. 

(I should outline the boolean logic in a future post!)

For example, one friend and colleague in Thailand is the CTO of True Internet, a leading telecommunications, voice, Video and Internet service provider in Thailand.   True processes myriad events on their network using a dynamic, self-learning neural networking technology.    The US company providing this very clever and highly recommended event processing application does not call themselves a “CEP vendor”; however, they process complex events better and more interesting than the band of merry self-described “CEP players”.

Again,  visualize the gentle giant elephant metaphor that Opher likes to use as a basis for his comments in CEP counterpoint.

When folks define the term “complex event processing” to match a technology marketing campaign that is primarily driven by software running rules against time-series data streaming in a sliding-time windows, and then go on to take the same software capabilities and apply these capabilities to problems that are suitable for that domain, then you match Opher’s elegant description of “a small view of the overall elephant”.

The fact of the matter is that the overall domain of event processing is at least two orders of magnitude larger (maybe more) than the combined annual revenue of the self-described companies marketing what they call “CEP engines.”  The very large “rest of the big elephant” is doing what is also “complex event processing” in everyday operations that are somehow overlooked in “other” analysis and counterplay.

Therefore,  I kindly remain unmoved from my view  that the self-described CEP community, as currently organized, is not immune to counterpoint using the same gentle giant elephant metaphor.  I like this metaphor and hope well-respected colleagues will continue to use this metaphor; because we can easily apply this elegant manner of discussion to explain why the current group of self-described CEP vendors are, in a manner of speaking, selling Capital Market Snake Oil because they are making outrageous claims about the capabilities of their products, as if they can solve the entire “elephant” of event processing problems.   Recently, in this article, CEP was positioned as a technology to mitigate against corporate megadisasters like the subprime meltdown.

Advice:  Tone down the hype.

Furthermore, the noise in the counter arguments marginalize most of the real event processing challenges faced by customers.

In consistant and well respected rebuttal, Opher likes to use the “glass half-full, half-empty” metaphor.   Opher’s point is a valid attempt to paint my operational realism as “half empty” negativism; while at the same time positioning the promotion of the (narrow) event processing capabilities of the self-described CEP rules community as “half-full” thinking. 

For the record, I do see my worldview as “half full” or “half empty”; but an unbiased pragmatic view based on day-to-day interaction with customers with what they would call “complex event processing” problems. 

These same customers would fall over laughing if we tried to bolt one of these rule-based, time-series streaming data processing engines on their network and told them they can detect anything other than trival business events, business opportunities and threats, in near real-time. 

Is it “half empty” thinking to caution people that a “glass” of software that is being touted as the answer to a wide range of complex (even going so far in a recent news article to imply CEP would have magically stopped the subprime crisis!) tangible business problems is not really as that it is hyped to be?  

If so, then I plead guilty to honesty and realism, with the added offense of a sense of fiscal responsibility to customers and end users.

Clouding and Confusing the CEP Community

April 20, 2008

Ironically, our favorite software vendors have decided, in a nutshell, to redefine Dr. David Luckham’s definition of “event cloud” to match the lack-of-capabilities in their products.  

This is really funny, if you think about it. 

The definition of “event cloud” was coordinated over a long (over two year) period with the leading vendors in the event processing community and is based on the same concepts in David’s book, The Power of Events. 

But, since the stream-processing oriented vendors do not yet have the analytical capability to discover unknown causal relationship in contextually complex data sets, they have chosen to reduce and redefine the term “event cloud” to match their product’s lack-of-capability.  Why not simply admit they can only process a subdomain of the CEP space as defined by both Dr. Luckham and the CEP community-at-large? 

What’s the big deal?   Stream processing is a perfectly respectable profession!

David, along with the “event processing community,” defined the term “event cloud” as follows:

Event cloud: a partially ordered set of events (poset), either bounded or unbounded, where the partial orderings are imposed by the causal, timing and other relationships between the events.

Notes: Typically an event cloud is created by the events produced by one or more distributed systems. An event cloud may contain many event types, event streams and event channels. The difference between a cloud and a stream is that there is no event relationship that totally orders the events in a cloud. A stream is a cloud, but the converse is not necessarily true.

Note: CEP usually refers to event processing that assumes an event cloud as input, and thereby can make no assumptions about the arrival order of events.

Oddly enough, quite a few event processing vendors seem to have succeeded at confusing their customers, as evident in this post, Abstracting the CEP Engine, where a customer has seemingly been convinced by the (disinformational) marketing pitches  – “there are no clouds of events, only ordered streams.”

I think the problem is that folks are not comfortable with uncertainty and hidden causal relationships, so they give the standard “let’s run a calculation over a stream” example and state “that is all there is…” confusing the customers who know there is more to solving complex event processing problems.

So, let’s make this simple (we hope). referencing the invited keynote at DEBS 2007, Mythbusters: Event Stream Processing Versus Complex Event Processing.

In a nutshell…. (these examples are in the PDF above, BTW)

The set of market data from Citigroup (C) is an example of multiple “event streams.”

The set of all events that influence the NASDAQ is an “event cloud”.


Because a stream  of market data is a linear ordered set of data related by the timestamp of each transaction linked (relatively speaking) in context because it is Citigroup market data.    So, event processing software can process a stream of market data, perform a VWAP if they chose, and estimate a good time to enter and exit the market.  This is “good”.

However, the same software, at this point in time, cannot process many market data feeds in NASDAQ and provide a reasonable estimate of why the market moved a certain direction based on a statistical analysis of a large set of event data where the cause-and-effect features (in this case, relationships) are difficult to extract.  (BTW, this is generally called “feature extraction” in the scientific community.)


Because the current-state-of-the-art of stream-processing oriented event processing software do not perform the required backwards chaining to infer causality from large sets of data where causality is unknown, undiscovered and uncertain.

Forward chaining, continuous query, time series analytics across sliding time windows of streaming data can only perform a subset of the overall CEP domain as defined by Dr. Luckham et al.

It is really that simple.   Why cloud and confuse the community?

We like forward chaining using continuous queries and time series analysis across sliding time windows of streaming data. 

  • There is nothing dishonorable about forward chaining using continuous queries and time series analysis across sliding time windows of streaming data.   
  • There is nothing wrong with forward chaining using continuous queries and time series analysis across sliding time windows of streaming data. 
  • There is nothing embarrassing about forward chaining using continuous queries and time series analysis across sliding time windows of streaming data. 

Forward chaining using continuous queries and time series analysis across sliding time windows of streaming data is a subset of the CEP space, just like the definition above, repeated below:

The difference between a cloud and a stream is that there is no event relationship that totally orders the events in a cloud. A stream is a cloud, but the converse is not necessarily true.

It is really simple.   Why cloud a concept so simple and so accurate?

Some Comments on the EPTS Member Agreement

April 6, 2008

The Event Processing Technical Society (EPTS) has been meeting, informally, for around three years.  Now there is a Call for EPTS Founding Members, from the EPTS Steering Committee and a related Members Agreement for the EPTS.

Here are my initial comments:

First, the Member Agreement calls for the EPTS Steering Committee (EPTSTC), basically the same committee that has been in place for three years to date, to continue their work for two more years before a general election.  This means that the current committee will have been in place for more than 5 years before a general election is held.

My comment is that the folks currently on the EPTSTC are good people, there is no doubt about this.  However, I believe that the event processing community would be better served if a generally election was held within 3 months of formalizing the EPTS membership.

There are many reasons for doing this, and I don’t think it is necessary to describe all the benefits.  The benefits far outweight any downside, so I would urge the EPTS Steering Committee to revise the Member Agreement immediately (because the agreement was sent out before soliciting general comments from the EPTS community at large).

Second,  the Member Agreement specifies that every two years, only half of the Steering Committee will be elected.      I disagree with this approach and think that all of the Steering Committee should be reelected every two years.  

The rationale for this is that the EPTS Steering Committee is not a governing body like the US Congress where changes in public sentiment can impact national security.   It is much better to have the entire Steering Committee up for relection every two years.   

I have quite a few other concerns the with EPTS Member Agreement.   Basically, the agreement needs to be written with an eye toward a more flexible, open and inclusive process that puts the future of the EPTS square into the hands of the event processing community, not a small group of well intended folks who represent a small part of the overall event processing community and worldview.

In closing, the EPTS Membership Agreement should be rewritten and the draft should go out for open comments before sending out a final version (as was done this time).   The entire process should also be transparent, in my opinion.