Thank you for the answer, the thing is that I would not like to call external system for each Window, rather I woudl like to keep the gap size in Flink's state which I will be able to change from external system, for example handle configUpdate message from Kafka.
So if SessionWindowTimeGapExtractor should not be implemented on operators, then I understand that SessionWindowTimeGapExtractor implementation will fetch config value from Flink's state (value/map) according to the state descriptor. However I would not want to fetch data from the state for each call, because it will be changed not that often. It is similar case for Broadcast state pattern but for SessionWindowTimeGapExtractor case. -- Sent from: http://apache-flink-user-mailing-list-archive.2336050.n4.nabble.com/
