DEBS 2012 - highlights of the first conference day

I'll start from the last session - the poster and demo session.  During this session I wore the glasses shown in the picture, and it was the first glance towards the world of the glasses that Google is taking us.   It has a potential, but getting used to it is not intuitive,  one can see menu and then has to put a paper in the place to select among the menu options.   The demo was of an EU project that does human attention detection and  detect whether a person is interested in museum artifacts.  There have been some other demos and posters, many of them from EU projects.  Another interesting ones were one that provide safety alerts for monitoring underground trains, and another one which use events to help collaboration between team of software developers who work together.  

Getting back to the beginning -- the day started with the interesting keynote of Sethu Raman (the industrial keynote), already written about yesterday.    The next session has been an industry session.  It is interesting to note that around 1/3 of the participants here are from industry and not academia,   and the industry track became integral part of the program (not all academic people like it though!). 

In the afternoon there were two scientific papers sessions -- one on pub/sub, the original topic of DEBS, now reduced to a single track per conference,  the other one on "complex and spatial events".   I'll write a few sentences about it - slides can already be found on the conference's site: 

• The first paper was presented by Martin Hirzel from the IBM System S team about parallel complex event processing, Martin started with the old assertion that CEP is part of stream processing, since it is doing only pattern matching, while stream processing can also do aggregations.  I was never sure why this distinction is important, furthermore, as I have written before CEP is used by different people to mean different things, thus I would say that "event processing" is the name of functionality that does all.  In any event, the talk about parallel incremental computation was interesting.
• The second paper was presented by Alex Artikis from NCSR and event recognition (pattern matching) based on event calculus.   Formal approaches can be useful for that domain, and the event calculus is one of the first attempts to do it.  I have some terminology dispute with Alex, who equates the notion of fluent from event calculus to composite event.  I think it is actually refers to a state that can be initiated and terminated by events, and may serve as context or state. 
• The third paper was presented by Michael Olson,  Mani Chandy's PhD student in CalTech.  He presented the latest on their going on project on geo-spatial events (relate to seismic events)
• The fourth paper was present by Boris Koldehpfe from University of Stuttgart, who also active in the community for several years.  Boris talked about range queries in distributed event processing systems, where range queries relate to spatial operators on events.   It seems that the spatial dimension which was also discussed in the previous talk is gaining more traction. 

 I'll write about the sessions of today at a later point.

On Alex Buchmann's 60th birthday book

 Alex Buchmann is an old friend, we first met when both of us were 20 years younger, and worked on active databases.  Alex is a little bit older than me, and recently celebrated his 60th birthday.  I could not travel to the ceremony in Darmstadt, but as a gift, contributed to the book, which includes a collection of papers edited by Alex's students (or ex-students).  Today the mail has brought me a copy of this book, with personal inscription from Alex.  The book is called "From Active Data Management to Event-Based Systems and More".   

More detailed about the book can be obtained in the Springer LNCS site.    The book includes a paper entitled "Spatial perspectives of event processing" co-authored with Nir Zolotorevsky.   Browsing the book I see that I am in a very good company, some of the other authors are: Jean Bacon and Ken Moody, Mani Chandy, Umesh Dayal, Tamer Ozsu,  Gerhard Weikum, and many others. 


When I summarized the year 2009 in this Blog, I have written that the quote of the year is taken from Alex's keynote address in DEBS 2009, stating is using regular database techniques for event-based systems is like trying to drink the water in a waterfall using a straw.    Alex also does not like the term "event processing", claiming that "processing" sounds like "data processing" which is an archaic term, and prefers to talk about event-based systems, as shown in the title of the book.


I wish Alex many more years of  good health, fruitful work and fun.

More on spatial event processing

This is a map of my home city, Haifa, which shows it northern part, I live in the south part outside this picture. I had some internal discussions this week about the role of location information in event processing, this is somewhat similar to the roles that time has in event processing, though the use of time is more pervasive, we see increasing number of applications that require spatial support. Some of the major utilizations of location information are:

1. Location as a context: The location is used to group events together as they serve as input for any event processing function such as: aggregation of pattern matching.
2. Location as enabler for spatial patterns: The locations of events is used in the function that determined whether a certain pattern is being matched.

Note that these two roles of locations are orthogonal.

An example for the first role: count all the police vehicles that are within 5 KM from a crime scene, where there are periodic events that identify the location of the police vehicles using GPS devise. In this case, location is done to find out which events are "in context", and the event processing function itself is a simple aggregation (count).

An example for the second role: A certain company experienced over one week, 20 events of breaking into employees houses, it an an attempt to figure out whether this is a work of a single person, the pattern that is matched is: the maximal distance between two breaking in events that occurred within a single night is less than 15KM. In this case the context is not spatial, since the events involved are determined by time ("a single night") and segmentation ("events related to houses of employees"), but the pattern that we are looking for is spatial, since it involves location.

As said, time can also play in the context role, in the pattern role, in both, or in none.

More on spatial event processing - later.

On spatial relations between events and entities

During the final pass of revisions for the EPIA book, we have re-visited the issue of spatial context, one of the options of spatial context is to group or partition events according to the relationship between event and a certain entity. However, location is not necessarily a point, there are three main type of location: point, line (or poly-line) and area (polygon). This is true for entity, but it is also true for an event, if the event is located using GPS, then a point coordinate is obtained, but if an event is located using the signal sent from a cellular phone, then the location of the event is a cell, i.e. it occurs within an area. We can also say that a vehicle is somewhere on road M1, which is a poly-line. Given these three data types, we can define several relations among the location of the event, and the location of the entity, as shown in the illustration above, such as: contains --- the entity contains the event, disjoint etc... The illustration above shows the various cases between events of various location types and entities of various location types. Some examples of use cases for the various relations will follow in one of the next postings, meanwhile -- you can think about applications yourself

On composite contexts

Today is a happy day to the Israeli scientific community it was announced that Professor Ada Yonath from the Weizmann Institute won a Nobel prize in chemistry, this adds to two Israeli scientists that won a Nobel prize in chemistry a few years ago, so Israel is a chemistry super-power. Computer science was not exist when Nobel decided on prizes, the equivalent is Turing Awards, that, if I am not mistaken, have been already awarded to three Israeli scientists, so we are not bad in this area either..

Back to event processing thinking --- getting progress on the EPIA book, yesterday we had two hours review with the editor on editorial stuff around the last three chapters, and upon revision, it will get to the 2/3 review. Our target date for publication is now April 2010, and this will probably be the final target.

Anyway, to continue my previous posting on contexts, I would like to discuss the notion of context composition. Recall that context is grouping of events based on one of the following: time, space, state and segment, for either grouping in order to apply operations on this group, or make distinct behavior for distinct groups. Composite context -- as its name suggests is just a multi-dimensional context, i.e. it contains cross-section of several contexts.
In the picture below this is a composition of segmentation ("per customer") and time (in this case fixed sliding temporal interval - per hour, each square is a context partition.


This is just example of combination, there are other useful compositions such as: spatio-temporal context: partition with one dimension is time and one is location oriented, or space and state contexts combination, example: spatial context == within the city of Trento, state of weather = {sunny, cloudy, rainy, snowing}, in each of these partitions other agents are applicable.

Somebody asked me -- what is the benefit of using the context abstraction anyway --- the answer is, like any other abstraction -- it saves work. The same application can be written with much less code and is much simpler to develop, maintain and understand --- the use of context is quite useful in this sense, see also some discussion by Marco. Next -- I'll write more about the next chapters on event processing patterns, stay tuned.

More on DEBS 2009

I am still in the DEBS conference venue, in a time gap between the conference sessions and the conference dinner that will be held here in an hour or so. This is the time to provide some more comments about DEBS 2009. The conference will continue tomorrow, but I'll skip the last day, going to NY for some IBM meetings. Spending whole three days in a conference is a heavy toll on my busy schedule, but it is fun. The next conference will be held in Cambridge, UK, and the call for papers (above) has been distributed. Today Alex Buchmann gave the second keynote address about some event processing applications and research challenges, I hope that Alex will make his slides available to the public. Also today there have been sessions of demos and posters, mostly by Ph.D. students, mostly concentrate on the transport area, pub/sub, messaging etc... We need more Ph.D. students on the event processing topics. Next there has been a fast abstract session that present work in progress in 10 minutes. I have presented a work in progress on spatial aspects of event processing, and will write more in the future about this activity.


Back to yesterday, the industry track was divided into two parts: industrial reports and a panel. In the industrial reports there was one, presented by Florian Springer, that the audience will remember for long time, not so much because the content of the talk, but since Florian made a point about importance of standards, by showing real-life examples for standards, and the example he chose was condoms, which, according to Florian, have a standard - they are all in the same size. People kept talking about it.

I have moderated the panel about academia/industry relations in event processing, and posed the following questions (see slide below)



The first question was, whether the academia should work on incremental stuff related to current technology, or on disruptive technologies, making current technologies obsolete, which was translated to the question --- do we want to clone John Bates to develop new technologies that will make the technology created by the original John Bates as obsolete. John Bates, who was in the audience, reacted by saying that his wife will not like the idea of cloning him, since she thinks that one of this type is more than enough. The panelists were two persons from academia, and two from industry. One of the industrial people was Richard Tibbetts, Streambase CTO, who showed the famous Gartner hype-cycle picture, claiming that the event processing area is already approaching the plateau. I think that he is a bit optimistic, in my opinion, we are not even at the peak of inflated expectations...

There was also some discussion about teaching event processing courses, and the fact that today it takes a lot of time to get a university graduate being effective in developing event processing applications, since they need to be taught to think in a different way. There have been some more talks, but I am tired from writing, so that's all for now.... Tomorrow early morning -- flying to NYC.