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Posted to dev@beam.apache.org by Andrei Arion <an...@gmail.com> on 2021/01/19 08:20:22 UTC
Unbounded pipeline: how to trigger a computation on empty windows
Hello,
I have tried to use Event Time Timers cf https://beam.apache.org/blog/timely-processing/ but i cannot seem to find a way to set the timer (when there are no elements the process() method is never called...)
The closest answer that I could find on StackOverflow (https://stackoverflow.com/questions/54444718/apache-beam-how-to-trigger-empty-windows) seem to suggest that there is no alternative than inserting dummy/fake data ?
Is this true or there are better ways to achieve that.
Thank you,
Andrei
Re: Unbounded pipeline: how to trigger a computation on empty windows
Posted by Reza Ardeshir Rokni <ra...@gmail.com>.
You may want to explore the use of Looping Timers.
https://beam.apache.org/blog/looping-timers/
Please note that there are no order guarantees in OnProcess, some ideas on
solutions to this are explored in:
https://www.youtube.com/watch?v=Y_HoNNU6b3I
Cheers
On Wed, 20 Jan 2021 at 05:07, Reuven Lax <re...@google.com> wrote:
> What sort of windows are you using?
>
> On Tue, Jan 19, 2021 at 1:05 PM Andrei Arion <an...@gmail.com>
> wrote:
>
>> Hello,
>>
>> I have tried to use Event Time Timers cf
>> https://beam.apache.org/blog/timely-processing/ but i cannot seem to
>> find a way to set the timer (when there are no elements the process()
>> method is never called...)
>>
>> The closest answer that I could find on StackOverflow (
>> https://stackoverflow.com/questions/54444718/apache-beam-how-to-trigger-empty-windows)
>> seem to suggest that there is no alternative than inserting dummy/fake data
>> ?
>>
>>
>> Is this true or there are better ways to achieve that.
>>
>> Thank you,
>> Andrei
>>
>
Re: Unbounded pipeline: how to trigger a computation on empty windows
Posted by Reuven Lax <re...@google.com>.
What sort of windows are you using?
On Tue, Jan 19, 2021 at 1:05 PM Andrei Arion <an...@gmail.com> wrote:
> Hello,
>
> I have tried to use Event Time Timers cf
> https://beam.apache.org/blog/timely-processing/ but i cannot seem to find
> a way to set the timer (when there are no elements the process() method is
> never called...)
>
> The closest answer that I could find on StackOverflow (
> https://stackoverflow.com/questions/54444718/apache-beam-how-to-trigger-empty-windows)
> seem to suggest that there is no alternative than inserting dummy/fake data
> ?
>
>
> Is this true or there are better ways to achieve that.
>
> Thank you,
> Andrei
>