Do you mean you want to keep the origin window as well as doing some combine operations inside window in the same time? What kind of data do you expect the following operator will receive?
Best, Kurt On Thu, Oct 26, 2017 at 5:29 AM, Le Xu <sharonx...@gmail.com> wrote: > Thank Kurt I'm trying out WindowedStream aggregate right now. Just > wondering, is there any way for me to preserve the window after > aggregation. More specifically, originally i have something like: > > WindowedStream<Tuple2<String, Long>, Tuple, TimeWindow> windowStream = > dataStream > .keyBy(0) //id > .timeWindow(Time.of(windowSize, TimeUnit.MILLISECONDS)) > > and then for the reducer I can do: > > windowStream.apply(...) > > and expect the window information is preserved. > > If I were to do use aggregate on window stream, I would end up with > something like: > > DataStream<Tuple2<String, Long>> windowStream = dataStream > .keyBy(0) //id > .timeWindow(Time.of(windowSize, TimeUnit.MILLISECONDS)). > aggregate > (new AggregateFunction<Tuple2<String, Long>, Accumulator, Tuple2<String, > Long>>() { > @Override > public Accumulator createAccumulator() { > return null; > } > > @Override > public void add(Tuple2<String, Long> stringLong, > Accumulator o) { > > } > > @Override > public Tuple2<String, Long> getResult(Accumulator o) { > return null; > } > > @Override > public Accumulator merge(Accumulator o, Accumulator > acc1) { > return null; > } > }); > > Because it looks like aggregate would only transfer WindowedStream to a > DataStream. But for a global aggregation phase (a reducer), should I > extract the window again? > > > Thanks! I apologize if that sounds like a very intuitive questions. > > > Le > > > > > > > On Tue, Oct 24, 2017 at 4:14 AM, Kurt Young <ykt...@gmail.com> wrote: > >> I think you can use WindowedStream.aggreate >> >> Best, >> Kurt >> >> On Tue, Oct 24, 2017 at 1:45 PM, Le Xu <sharonx...@gmail.com> wrote: >> >>> Thanks Kurt. Maybe I wasn't clear before, I was wondering if Flink has >>> implementation of combiner in DataStream (to use after keyBy and windowing). >>> >>> Thanks again! >>> >>> Le >>> >>> On Sun, Oct 22, 2017 at 8:52 PM, Kurt Young <ykt...@gmail.com> wrote: >>> >>>> Hi, >>>> >>>> The document you are looking at is pretty old, you can check the newest >>>> version here: https://ci.apache.org/projects/flink/flink-docs-releas >>>> e-1.3/dev/batch/dataset_transformations.html >>>> >>>> Regarding to your question, you can use combineGroup >>>> >>>> Best, >>>> Kurt >>>> >>>> On Mon, Oct 23, 2017 at 5:22 AM, Le Xu <sharonx...@gmail.com> wrote: >>>> >>>>> Hello! >>>>> >>>>> I'm new to Flink and I'm wondering if there is a explicit local >>>>> combiner to each mapper so I can use to perform a local reduce on each >>>>> mapper? I looked up on https://ci.apache.org/proje >>>>> cts/flink/flink-docs-release-0.8/dataset_transformations.html but >>>>> couldn't find anything that matches. >>>>> >>>>> >>>>> Thanks! >>>>> >>>>> Le >>>>> >>>> >>>> >>> >> >