Hello Aljoscha <aljos...@apache.org> Thanks very much for clarifying the role of Pre-Aggregation (rather, Incr-Aggregation, now that I understand the intention). It helps me to understand. Thanks to Setfano too, for keeping at the original question of mine.
My current understanding is that if I have to compute the average of a streaming set of _temperatures_ then the *best* way to accomplish this, is by employing *one* node (or thread, on my laptop), losing speed but gaining deterministic behaviour in the process. I can decide to capture the average either by grouping the temperatures by count or by time. Because I am sliding the window anyway, I don't run the risk of accumulation of elements in the window and buffer overrun. Could you please confirm if my understanding is correct? I feel happy if I 'understand' the basis of a design well! :-) -- 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."
