Hi Marco, I'm not sure which API or SQL query do you use. If you use Windowed Stream API in DataStream [1]. The input data would be assigned to a Window based on which Window Assigner do you use. If using tumbling window, the input data would be assigned to a Window based on it's event-time and registers an event timer trigger for the Window. You could find more information in document [1]. When watermark passed the end of Window, the window would be triggered. The event time of the output element is inclusive upper bound of the trigged window. If you use Window Aggregation based on Flink SQL [2]. The situation is very similar.
[1] https://ci.apache.org/projects/flink/flink-docs-master/docs/dev/datastream/operators/windows/ [2] https://ci.apache.org/projects/flink/flink-docs-master/docs/dev/table/sql/queries/window-agg/ Best regards, JING ZHANG Marco Villalobos <mvillalo...@kineteque.com> 于2021年9月7日周二 下午2:24写道： > If an event time timer is registered to fire exactly every 15 minutes, > starting from exactly at the top of the hour (exactly 00:00, 00:15, 00:30, > 00:45 for example), and within that timer it produces an element in the > stream, what event time will that element have, and what window will it > belong to if I am using a 15 minute tumbling event time window? >
