Hi, the call to setAutoWatermarkInterval() is still necessary to activate the watermark-generation mechanism. However, calling setStreamTimeCharacteristic(EventTime) will also set a good default value for the auto watermark interval.
Cheers, Aljoscha On Mon, 24 Oct 2016 at 17:02 Paul Joireman <paul.joire...@physiq.com> wrote: > Hi all, > > The event timestamp and watermarks documentation (v. 1.1) > https://ci.apache.org/projects/flink/flink-docs-release-1.1/apis/streaming/event_timestamps_watermarks.html > states > that > > The AssignerWithPeriodicWatermarks assigns timestamps and generates > watermarks periodically (possibly depending on the stream elements, or > purely > based on processing time). > > The interval (every n milliseconds) in which the watermark will be > generated is defined via ExecutionConfig.setAutoWatermarkInterval(...). > Each time, the > assigner’s getCurrentWatermark() method will be called, and a new > Watermark will be emitted, if the returned Watermark is non-null and larger > than the > previous Watermark. > > It goes on to give an example of the > BoundedOutOfOrdernessTimestampExtractor. My question is that since the > BoundedOutOfOrdernessTimestampExtractor > is a sub-class of the AssignerWithPeriodicWatermarks is it necessary to > call ExecutionConfig.setAutoWatermarkInterval(...) on the environment in > order to actually generate watermarks or should they be generated > "automatically" by the subsequent operators. > > In other words, will an event time window still fire if this call > (setAutoWatermarkInterval) is not present? > > Regards, > Paul W Joireman >
