Re: Apache Flink - How to destroy global window and release it's resources
Posted by
Aljoscha Krettek on
URL: http://deprecated-apache-flink-user-mailing-list-archive.369.s1.nabble.com/Apache-Flink-How-to-destroy-global-window-and-release-it-s-resources-tp27191p27212.html
For a GlobalWindow, returning TriggerResult.PURGE (or FIRE_AND_PURGE) and removing all trigger state (meaning timers and state) will get rid of all state. There is no state for the GlobalWindow itself, it only semantically exists because of the elements in it and the Trigger state.
Aljoscha
Hi,
As far as I know, a window is only completely removed when time (event or processing time, depending on the window type) passes the window's end timestamp.
Since, GlobalWindow's end timestamp is Long.MAX_VALUE, it is never completely removed.
I'm not 100% sure what state is kept around. It might not be keyed state but just objects on the heap but not absolutely sure.
Aljoscha (in CC) should know the details here.
Best, Fabian
Am Do., 11. Apr. 2019 um 08:07 Uhr schrieb Guowei Ma <
[hidden email]>:
Hi,
I think you could return a proper TriggerResult, which defines how to deal with the window elements after computing a window in your trigger implementation. You could find the detail information from the doc[1].
Hi:
I have a use case where I need to create a global window where I need to wait for unknown time for certain events for a particular key. I understand that I can create a global window and use a custom trigger to initiate the function computation. But I am not sure how to destroy the window after the triggering conditions is satisfied and the the events are purged.
If there is any better way of dealing with this situation, please let me know.