Before a program close, it will emit Long.MaxValue as the watermark and that watermark will trigger all the windows. This is the reason why your `timeWindow` program could work. However, for the first program, you have not registered the event time timer(though context.timerService.registerEventTimeTimer) and also there is also no onTimer logic defined to process it.
> 在 2019年10月28日，下午4:01，杨力 <bill.le...@gmail.com> 写道： > > It seems to be the case. But when I use timeWindow or CEP with > fromCollection, it works well. For example, > > ``` > sEnv.fromCollection(Seq[Long](1, 1002, 2002, > 3002)).assignAscendingTimestamps(identity[Long]) > .keyBy(_ % 2).timeWindow(Time.seconds(1)).sum(0).print() > ``` > > prints > > ``` > 1 > 1002 > 2002 > 3002 > ``` > > How can I implement my KeyedProcessFunction so that it would work as expected. > > Dian Fu <dian0511...@gmail.com <mailto:dian0511...@gmail.com>> 于 > 2019年10月28日周一 下午2:04写道： > Hi, > > It generates watermark periodically by default in the underlying > implementation of `assignAscendingTimestamps`. So for your test program, the > watermark is still not generated yet and I think that's the reason why it's > Long.MinValue. > > Regards, > Dian > >> 在 2019年10月28日，上午11:59，杨力 <bill.le...@gmail.com >> <mailto:bill.le...@gmail.com>> 写道： >> >> I'm going to sort elements in a PriorityQueue and set up timers at >> (currentWatermark + 1), following the instructions in >> https://ci.apache.org/projects/flink/flink-docs-release-1.9/dev/stream/operators/process_function.html#timer-coalescing >> >> <https://ci.apache.org/projects/flink/flink-docs-release-1.9/dev/stream/operators/process_function.html#timer-coalescing>. >> >> However, it seems that context.timerService().currentWatermark() always >> returns Long.MinValue and my onTimer will never be called. Here's minimal >> program to reproduce the problem. Am I missing something? >> >> ``` >> val sEnv = StreamExecutionEnvironment.getExecutionEnvironment >> sEnv.setStreamTimeCharacteristic(TimeCharacteristic.EventTime) >> sEnv.setParallelism(argOps.parallelism()) >> sEnv.fromCollection(Seq[Long](1, 2, >> 3)).assignAscendingTimestamps(identity[Long]) >> .process(new ProcessFunction[Long, Long] { >> override def processElement(i: Long, context: ProcessFunction[Long, >> Long]#Context, collector: Collector[Long]): Unit = { >> collector.collect(context.timerService().currentWatermark()) >> } >> }).print() >> sEnv.execute() >> ``` >> >> ``` >> -9223372036854775808 >> -9223372036854775808 >> -9223372036854775808 >> ``` >> >
