Monday, January 21, 2008

Unplanned events - again

This (more or less) how my MPV car looked like at the beginning of this day, unfortuantely, it does not look like this now -- while driving in a highway, there was some traffic congestion, and the traffic slowed down, however, the driver behind me has not detected this event and proceeded to drive full speed - as a result he crashed his small car into my car, totally destroyed his car, but made also substantial damage to the back of my car. So - I had an absent event, did not make the meeting I was driving to, had to wait for police, and then almost two hours for a replacement car from the leasing company -- so wasted much of the day. Luckily for me, I have detected that with the momentum of the crash, I am approaching very quickly a track before me -- and succeeded to stop the car before getting into the track -- otherwise, I may not be sitting at home and typing now -- so people also need to process events in real-time and not in batch...


Eran said...

That's a good proof for real-time event processing, and for the advantage of big, heavy, cars. It is also a demonstration of the need to share events. If the driver behind you had the knowledge that you had when breaking, her (or his) behavior would be different.

Richard Veryard said...

Congratulations on your fast reactions, and commiserations on the slower reactions of the driver behind. Clearly there are some events you have to process in real time. But I hope you are not implying that all events must be processed in real-time. When the fuel tank indicator appears, do you refuel immediately or do you wait until you reach the next gas station? How often do you have the vehicle serviced?

I think the critical question for systems designers here is to determine which are the events that call for a real-time response, and which are the events where a batch response is more appropriate.

Surely the event infrastructure should be capable of handling both.