Hi Jungtaek,
Sorry for the slow reply and thanks for the feedback on the book! :-)
As I said, I don't think Flink's windowing API is well suited to deal with
the problem of manually terminated session windows due lack of support to
split windows.
Given that Spark has similar support for timers, I
Thanks Fabian on providing great input!
Regarding your feedback on solution, yes you're right I realized I missed
out-of-order events, and as you said we have to "split" existing window
into two which current abstraction of custom window couldn't help here.
(Flink would have no idea how aggregated
Hi Jungtaek,
I would recommend to implement the logic in a ProcessFunction and avoid
Flink's windowing API.
IMO, the windowing API is difficult to use, because there are many pieces
like WindowAssigner, Window, Trigger, Evictor, WindowFunction that are
orchestrated by Flink.
This makes it very har
Thanks Dongwon to provide feedback and share your approach!
I'm not sure it could be possible (not an expert), but if we could reset
intermediate result (aggregated) after processing "fire event", I guess it
would work as expected, as window would still expand even after "session
end", but it will
Hi Jungtaek,
I've faced a similar problem in the past; we need to calculate an aggregate
upon receiving an end message from each user.
While you're trying to solve problem by defining a custom window assigner,
I took a different approach to the problem by implementing a custom trigger.
You can s
Hi Flink users,
I've been spending time to learn and play with Flink DataStream API, not an
expert level but as a beginner. :)
To play with custom window API, I just created a small example, session
window based on fixed time gap, but indicate the type of event which may
contain "end of session".
