Recently I presented a talk about Esper at JTeam Tech Meeting. Please go through the slides if you are interested in understanding more about Complex Event Processing and Esper . The first half of the presentation covers conceptual knowledge of Complex Event Processing, its advantages over traditional approaches and use cases. The second part covers API details of Esper – The Open Source CEP Engine written in Java.
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Complex Event Processing (CEP) is a buzzword that’s been running around the industry for last couple of years. The concept was introduced by David Luckham of Stanford University who has done over a decade of research in this field. Let’s try to understand some terms that are used frequently in this arena.
An Event is a piece of data that represents that something happened in the real world, or in software system. Events often observe a change in state. e.g. a stock tick or a password change. A linearly ordered sequence of events forms Event Stream. While a partially ordered set of events form Event Cloud. So an event stream could be a cloud but the reverse need not be true.
e.g. Set of all stock trades for GOOG within a 5 minute time window is an Event Stream. While all Stocks sold in a business day is an Event Cloud. And above event stream could be a part of this event cloud.
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I am blogging after a while and this time nothing related to human psychology. Lets talk something about technology.
At my work, ‘m many times involved in performance tuning of the applications. May it be a batch application or UI app, the culprit is always considered as the Data Layer. Its not true always. I worked on one UI application, where we tuned the data layer to the best possible state, but no luck. Recently I came across YSlow. YSlow checks how the HTTP protocol is implemented. ‘m almost a year late on this, but as rightly said Better Late Than Never.
Check this out!!
http://developer.yahoo.net/blog/archives/2007/08/yslow-podcast-screencast.html
