Hi Miyuru, what you need should be something like a `SlidingCountWindow`. Flink Datastream API has already provided a `countWindow()` method for that and a related example can be found here <https://github.com/apache/flink/blob/baebbabfc6913598122fc5df8645097172bd9e65/flink-examples/flink-examples-streaming/src/main/java/org/apache/flink/streaming/examples/windowing/WindowWordCount.java>.
Hope that helps, Xingcan > On 12 Mar 2018, at 1:33 PM, Miyuru Dayarathna <miyu...@yahoo.co.uk> wrote: > > Hi, > > I need to create a sliding window of 4 events in Flink streaming application. > The window should slide by one event per every new arriving event. > Furthermore, per each new arriving event I need to calculate the aggregate > sum of a particular field in the 4 events I have in the window. I have > referred [1] which describes how this can be implemented based on time. But > my use case if little different, hence I am wondering how the window can be > slided when a new event gets added to the window. > > [1] > https://ci.apache.org/projects/flink/flink-docs-release-1.4/dev/stream/operators/windows.html#sliding-windows > > <https://ci.apache.org/projects/flink/flink-docs-release-1.4/dev/stream/operators/windows.html#sliding-windows> > > Thanks, > Miyuru
