Dear flinker:
Look at the contradiction between event time and natural time from EventTimeTrigger.java (the window at the time of the break and the end of the window at the end of the end must not be "real time"): From the default EventTimeTrigger source code, I found that only onElement method (will judge the watermark) and onEventTime method only have a chance to trigger TriggerResult.FIRE; Therefore, the default EventTimeTrigger is assumed and must be "never stop! The data stream" will have "correct" Real-time results, so as long as the interval between the two eventtimes is too large, greater than the time window interval, or the end time of the window has not arrived yet, there is no new data (flow interruption, neither element(onElement) nor eventtime(onEventtime)), then the latest time the output of the window must be untimely or non-real-time (if i use eventtime to do the bounded window aggregation of the stream, i must have the near future data support, once it is interrupted, it will not be real-time), and i must wait until the new data stream is connected. The window result that was not output in time before the new data stream is come. (OnProcessingTime will never be called after EventTime is set, so modifying onProcessingTime has no effect. Called when a processing-time timer that was set using the trigger context fires.). Then, to "real time TriggerResult" can only 1. use processing-time 2. "guaranteed" stream data event time interval is small and best sequential and never interrupted (if this can be guaranteed, use processing-time directly. What is the meaning of using EventTime and Watermark in the production environment and how to test the real-time and accuracy of the data results? I am sorry I have confused from some flink streaming sql examples about the time window.) 3. Add new implementations or improvements: the end time of window determined by assignWindows can trigger TriggerResult as soon as it reaches the natural time point or reaches the natural time point plus to watermark interval. Real-time results [unrelated to the specific Tumble Hop Session], while to the time of TriggerResult.FIRE... The watermark has increased, but there is no data, and then the window trigger has stopped... I don't know if my understanding is correct, I also hope to give pointers. Thanks.
