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From M Singh <mans2si...@yahoo.com>
Subject Re: Apache Flink - Question about dynamically changing window end time at run time
Date Wed, 24 Apr 2019 11:47:23 GMT
 Hi Rong:
Thanks for your answer.
>From what I understand the dynamic gap session windows are also created when the event
is encountered.  I need to be able to change the window end time at a later time based on
what other events are in that window.  One way to do this is to use GlobalWindows but then
these are never deleted.

Regarding CEP option - I believe that CEP patterns cannot be changed dynamically once they've
been complied which limits it usage.
 Please feel free to correct me. 

Thanks for your help and pointers.

    On Tuesday, April 23, 2019, 8:12:56 PM EDT, Rong Rong <walterddr@gmail.com> wrote:
 Hi Mans,
I am not sure what you meant by "dynamically change the end-time of a window. If you are referring
to dynamically determines the firing time of the window, then it fits into the description
of session window [1]: If you want to handle window end time dynamically, one way of which
I can think of is the dynamic gap, session window [1] approach. with which you can specify
the end-time of a window based on input elements. Provided that you are maintaining a session
window. Another way to look at it is through the Flink-CEP library [2]. 

[1] https://ci.apache.org/projects/flink/flink-docs-release-1.8/dev/stream/operators/windows.html#session-windows[2] https://ci.apache.org/projects/flink/flink-docs-release-1.8/dev/libs/cep.html#groups-of-patterns
On Tue, Apr 23, 2019 at 8:19 AM M Singh <mans2singh@yahoo.com> wrote:

I am working on a project and need to change the end time of the window dynamically.  I want
to find out if the end time of the window is used internally (for sorting windows/etc) except
for handling watermarks that would cause problems if the end time was changed during run time
after the window has been created even if no new event has arrived for that window.

I don't want to use GlobalWindow since from my understanding it never gets destroyed.

If there is any alternate way of dealing with this, please let me know.


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