Hi Benchao, Thanks for the input.
The code is self-explanatory. Best, Dongwon On Thu, Dec 10, 2020 at 12:20 PM Benchao Li <libenc...@apache.org> wrote: > Hi Dongwon, > > I think you understand it correctly. > You can find this logic here[1] > > [1] > https://github.com/apache/flink/blob/master/flink-streaming-java/src/main/java/org/apache/flink/streaming/runtime/streamstatus/StatusWatermarkValve.java#L108 > > Dongwon Kim <eastcirc...@gmail.com> 于2020年12月10日周四 上午12:21写道： > >> Hi, >> >> Let's consider two operators: A (parallelism=2) and B (parallelism=1). >> B has two input partitions, B_A1 and B_A2, which are connected to A1 and >> A2 respectively. >> >> At some point, >> - B_A1's watermark : 12 >> - B_A2's watermark : 10 >> - B's event-time clock : 10 = min(12, 10) >> - B has registered a timer at 12 >> - No data will be fed into the pipeline for the next few hours, but I >> want the timer to be fired after a few seconds if no data is coming. >> >> After adopting a watermark strategy explained in [1], I found that the >> timer is fired as wished! That's awesome! >> >> But I want to know what happens inside in detail. >> Based on my current understanding of how watermark is calculated [2], I >> cannot come up with what happens inside when idleness is considered. >> If B_A2 is marked idle earlier than B_A1, is B's event-time clock >> calculated as min(12, MAX_WATERMARK)? >> >> Thanks, >> >> Dongwon >> >> [1] >> https://ci.apache.org/projects/flink/flink-docs-stable/dev/event_timestamps_watermarks.html#dealing-with-idle-sources >> [2] >> https://ci.apache.org/projects/flink/flink-docs-stable/dev/event_timestamps_watermarks.html#how-operators-process-watermarks >> [3] >> https://cwiki.apache.org/confluence/display/FLINK/FLIP-126%3A+Unify+%28and+separate%29+Watermark+Assigners >> > > > -- > > Best, > Benchao Li >
