Take a look at the section of Flink documentation titled "Event Time and Watermarks": https://ci.apache.org/projects/flink/flink-docs-release-1.4/dev/event_time.html#event-time-and-watermarks
Also read the excellent series "Streaming 101" and "102", has useful animations depicting the flow of time: https://www.oreilly.com/ideas/the-world-beyond-batch-streaming-101 https://www.oreilly.com/ideas/the-world-beyond-batch-streaming-102 Think of the watermark as a clock, ticking along due to information from the connector or from a watermark generator. Hope this helps, Eron On Sat, Dec 16, 2017 at 8:07 AM, chen <eric__...@126.com> wrote: > eventTime, lateness, maxoutoforderness are all about time. > event Time is the water mark time on the record. > lateness is record time or the real word time? > maxoutoforderness is record time or the real word time? > > dataStream.keyBy(row -> (String)row.getField(0)) > .window(TumblingEventTimeWindows.of(Time.seconds(5))) > .allowedLateness(Time.seconds(5)) > .fold(initRow(), new MyFoldFunction()) > > public Watermark getCurrentWatermark() { > return new Watermark(currentTime - 5000);} > > Does anyone could explain the time of eventTime,lateness, > maxoutoforderness? > > > > -- > Sent from: http://apache-flink-user-mailing-list-archive.2336050. > n4.nabble.com/ >
