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From Kostas Kloudas <k.klou...@data-artisans.com>
Subject Re: Window Functions and Empty Panes
Date Tue, 18 Apr 2017 21:11:25 GMT
No problem! Glad I could help!

Kostas

> On Apr 18, 2017, at 11:01 PM, Ryan Conway <ryanmackenzieconway@gmail.com> wrote:
> 
> Hi Kostas,
> 
> Re restarting: I missed that ProcessFunction.OnTimerContext extends ProcessFunction.Context!
Until now my thought was that OnTimerContext did not provide a means of restarting a timer.
> 
> Re initial timer, you're right, I'll just need to track a boolean in a state variable
that notes whether or not the timer has been initialized. What I am not confident about is
how to manage timer recovery after a node failure; I imagine it will make sense to not track
this variable. I will do more research and cross that bridge when I get there.
> 
> So I think a process function will work just fine, here. Thank you again for your time,
Kostas and Konstantin.
> 
> Ryan
> 
> On Tue, Apr 18, 2017 at 12:07 PM, Kostas Kloudas <k.kloudas@data-artisans.com <mailto:k.kloudas@data-artisans.com>>
wrote:
> Hi Ryan,
> 
> “A periodic window like this requires the ability to start a timer without an element
and to restart a timer when fired.”
> 
> For the second part, i.e. “to restart a timer when fired”, you can re-register the
timer in the onTimer() method (set a 
> new timer for “now + T"), so that the next one fires after T time units, where T is
your period.
> 
> For the first part, where you set the initial timer for a window, this needs to have
a first element right? If not, how
> do you know the key for which to set the timer? Are all the keys known in advance?
> 
> Kostas
> 
> 
> 
>> On Apr 18, 2017, at 8:35 PM, Ryan Conway <ryanmackenzieconway@gmail.com <mailto:ryanmackenzieconway@gmail.com>>
wrote:
>> 
>> A periodic window like this requires the ability to start a timer without an element
and to restart a timer when fired.
> 
> 


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