flink-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Dawid Wysakowicz <wysakowicz.da...@gmail.com>
Subject Strange behaviour of windows
Date Mon, 07 Dec 2015 19:32:25 GMT

I have recently experimented a bit with windowing and event-time mechanism
in flink and either I do not understand how should it work or there is some
kind of a bug.

I have prepared two Source Functions. One that emits watermark itself and
one that does not, but I have prepared a TimestampExtractor that should
produce same results that the previous Source Function, at least from my
point of view.

Afterwards I've prepared a simple summing over an EventTimeTriggered
Sliding Window.

What I expected is a sum of 3*(t_sum) property of Event regardless of the
sleep time in Source Function. That is how the EventTimeSourceFunction
works, but for the SourceFunction it depends on the sleep and does not
equals 3*(t_sum).

I have done some debugging and for the SourceFunction the output of
ExtractTimestampsOperator does not chain to the aggregator operator(the
property output.allOutputs is empty).

Do I understand the mechanism correctly and should my code work as I
described? If not could you please explain a little bit? The code I've
attached to this email.

I would be grateful.

Dawid Wysakowicz

View raw message