Timer Service vs Custom Triggers

[Aeden Jameson <ae...@gmail.com>]

My use case is that I'm producing a set of measurements by key every
60 seconds. Currently,  this is handled with the usual pattern of
keyBy().window(Tumbling...(60)).process(...) I need to provide the same
output, but as a result of a timeout. The data needed for the timeout
summary will be in the global state for that key. This seems possible by
either using the timer service in the process function without a window
(e.g. keyBy(..).process(..)) or by using a customer trigger. Why choose one
or the other?

-- 
Thanks,
Aeden

GitHub: https://github.com/aedenj
Linked In: http://www.linkedin.com/in/aedenjameson

Re: Timer Service vs Custom Triggers

[Caizhi Weng <ts...@gmail.com>]

Hi!

If you'd like to aggregate something on the records before time out, then
you want to consider using session window (instead of writing your own
trigger). However if aggregation is not needed I would prefer using a
process function to process watermark by myself, as the registered timer in
the window are stored in memory for each record, and if you have a very
large data flow this might cause a shortage in heap memory.

Aeden Jameson <ae...@gmail.com> 于2021年8月19日周四 上午8:07写道：

> My use case is that I'm producing a set of measurements by key every
> 60 seconds. Currently,  this is handled with the usual pattern of
> keyBy().window(Tumbling...(60)).process(...) I need to provide the same
> output, but as a result of a timeout. The data needed for the timeout
> summary will be in the global state for that key. This seems possible by
> either using the timer service in the process function without a window
> (e.g. keyBy(..).process(..)) or by using a customer trigger. Why choose one
> or the other?
>
> --
> Thanks,
> Aeden
>
> GitHub: https://github.com/aedenj
> Linked In: http://www.linkedin.com/in/aedenjameson
>
>