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From anna stax <annasta...@gmail.com>
Subject Re: How to trigger a function on the state periodically?
Date Tue, 10 Jul 2018 03:38:27 GMT
Thanks Hequn, for the links.

This is my use case..

When there is no user activity for n weeks, I need to send a Notification
to user.
The activity stream is usually very high volume for most users.
I thought it is not a good idea to use windowing for this, because of the
stream volume and window size.
I want to store in the state, for every user the last activity date and
process them once daily.

I want to make sure I am heading in the right direction. Thank you for your


On Mon, Jul 9, 2018 at 7:16 PM, Hequn Cheng <chenghequn@gmail.com> wrote:

> Hi anna,
> > I need to trigger a function once every day
> If you want to trigger by the function itself, you can use the
> Timer[1]. Both types of timers (processing-time and event-time) are
> internally maintained by the TimerService, and onTimer() method will be
> called once a timer fires.
> If you want to trigger the function of different
> parallelism synchronously, then the broadcast state[2] may be helpful.
> Hope this helps.
> Hequn
> [1] https://ci.apache.org/projects/flink/flink-docs-
> master/dev/stream/operators/process_function.html#timers
> [2] https://ci.apache.org/projects/flink/flink-docs-
> master/dev/stream/state/broadcast_state.html
> On Tue, Jul 10, 2018 at 7:47 AM, anna stax <annastax80@gmail.com> wrote:
>> Hi all,
>> I need to trigger a function once every day to read the state and create
>> kafka events and also remove some records from state if they are too old.
>> Is there a way to do this? I am new to Flink, appreciate any feedback and
>> suggestions.
>> Thanks
>> Anna

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