Hi, I think if you're keying by the same key the order should be preserved. If not, then events from different upstream operations can arrive in arbitrary order.
Best, Aljoscha > On 12. Jan 2018, at 12:57, Michał Stępień <mstep...@freeportmetrics.com> > wrote: > > Hello, > > I have dev related question. > > How will Flink behave when processing events in WindowFunciton (version 1.3 > or 1.4 including ProcessWindowFuncton) produces multiple events? Does Flink > guarantee that ProcessFunction will process them in order after window > outputs them in order into Collector for given key? Moreover, I understand > that Flink won't process next event in ProcessFunction as long as it won't > finish previous one for given key. > > Code: > > env.addSource(eventSource) > .assignTimestampsAndWatermarks(timestampsAndWatermarksGenerator) > .keyBy(FLINK_GROUPING_FIELD_NAME) > > .window(TumblingEventTimeWindows.of(Time.milliseconds((WINDOW_DURATION_MILLIS)))) > .apply(windowFunction) > .keyBy(FLINK_GROUPING_FIELD_NAME) > .process(processFunction) > .addSink(sinkFunction); > > -- > Pozdrawiam/Regards, > Michał > > *Michał Stępień* > Developer > *freeportmetrics.com <http://freeportmetrics.com/>* | +48 22 253 25 13 > <%2B48%20660%20507%20111>
