Hi, It depends on how many different users. In most cases, the performance will be fine. I think it worth to give a try. :-) Of course, there are ways to reduce the number of timers, for example keyBy(userId%1024), and use a MapState to store different users for the same group.
On Tue, Jul 10, 2018 at 1:54 PM, anna stax <annasta...@gmail.com> wrote: > Thanks Hequn. I think so too, the large number of timers could be a > problem. > > On Mon, Jul 9, 2018 at 10:23 PM, Hequn Cheng <chenghe...@gmail.com> wrote: > >> Hi anna, >> >> According to your description, I think we can use the Timer to solve your >> problem. The TimerService deduplicates timers per key and timestamp. Also, >> note that a large number of timers can significantly increase checkpointing >> time. >> >> On Tue, Jul 10, 2018 at 11:38 AM, anna stax <annasta...@gmail.com> wrote: >> >>> 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 suggestions. >>> >>> -Anna >>> >>> On Mon, Jul 9, 2018 at 7:16 PM, Hequn Cheng <chenghe...@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/s >>>> tream/operators/process_function.html#timers >>>> [2] https://ci.apache.org/projects/flink/flink-docs-master/d >>>> ev/stream/state/broadcast_state.html >>>> >>>> On Tue, Jul 10, 2018 at 7:47 AM, anna stax <annasta...@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 >>>>> >>>> >>>> >>> >> >
