Sunday, February 12, 2012

Crash course to build simple EP application using Esper


A crash course claimed to take less than an hour entitled "A simple introduction to complex event processing" has been posted.  This is done by example, which seems to be indeed very simple, finding "decreasing" or "increasing" pattern over two consecutive events and setting the color as green or red.   The main emphasis is on the setting - how to obtain, define and use events, and configure the engine - threadpools, listeners etc...  However not much about what event processing actually can do -- this is probably the next lesson.


  Esper is contrasted with commercial products since its open source model allows developers to play with it, use it for toy examples, and for daily usage that is not necessarily a commercial application of big enterprise, in our days of enterprise computing this approach has certainly a role to play, it should be noted that Esper is not the only open source in this area, and that some of the commercial products allow free development version (not access to the source code, but enabling developers to use the product for these purposes for free).


Anyway -- if you wish to learn Esper, it is a good start. 

3 comments:

Mohan Radhakrishnan said...

I have been reading many blogs about CEP over the past weeks.
We receive streaming messages from FI switches. These signify card authorization and merchant settlement messages. As a beginner I am trying to understand how to create a simple internal RFP to design a system that handles events. This is basically an effort to categorize the messages as events so that a case is build of CEP systems.

Is there a way to go about gathering requirements keeping in mind that this could be a event processing application. What general analysis techniques do you recommend ?
I know about David's original book on events and "Comprehensive Guide to
Evaluating Event Stream
Processing Engines". The latter document from coral8 is very useful but one step ahead of the requirements gathering phase.

Opher Etzion said...

Hi Mohan. There is a large variety between event processing systems, mainly in the non functional requirements. A tutorial of non functional aspects can be found here:
http://www.slideshare.net/opher.etzion/debs-2011-tutorial-nf-rofeventprocessing

As for the functional requirements: you can refer to the event processing manifesto
http://drops.dagstuhl.de/opus/volltexte/2011/2985/

Good luck, if you have specific questions - we can communicate directly.

Opher

Celticht32 said...

Mohan,
you have touched on one of my sore points as an architect doing EDA within the enterprise. There is no easy way to catalog and model an EDA architecture. I use a mixture of tools from Visio, Free mind to plain old spreadsheets to keep track of everything. If there is anything out there to handle the modeling and the soup to nuts that one needs I would love to see and try it out...


Chris