Hello Flinksters, This is perhaps too trivial for most here in this forum, but I want to have my understanding clear.
I want to find the average of temperatures coming in as a stream. The tuple as the following fields: probeID,readingTimeStamp,radiationLevel,photoSensor,humidity,ambientTemperature The 'readingTimeStamp' field provides the 'Event Time', and this provides the basis of the timeWindow(10) that I employ. I _keyBy_ the 'readingTimeStamp' and collect readings for next 10 seconds, and then I compute the average of the 'ambientTemperature'. After every 10 seconds, I want to be able to find the average temperature *so far* (a single value). Because my application defaults to parellelism == 4 (my laptop is 4 core), my understanding is that just by using a combination of an appropriate RichXXXFunction() and saving State in the RuntimeContext, I may not get the correct result. This is because, depending the way the Keys are distributed, 4 _different_ averages will be produced. Is this understanding right? If so, is using a *Broadcast variable*, the solution? Please help me plug the gap in understanding, if any. -- Nirmalya -- Software Technologist http://www.linkedin.com/in/nirmalyasengupta "If you have built castles in the air, your work need not be lost. That is where they should be. Now put the foundation under them."
