Hi all, The documentation for event timestamps and watermarks (https://ci.apache.org/projects/flink/flink-docs-release-1.1/apis/streaming/event_timestamps_watermarks.html) states that the
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 viaExecutionConfig.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.
