Hi all,
Just a point of clarification on how watermarks are generated. I'd like to
use a SlidingEventTime window of say 5 minutes with a 30 second slide. The
incoming data stream has elements from which I can extract the timestamp but
they may come out of order so I chose to implement the following timestamp
assigner.
my_stream.assignTimestampsAndWatermarks(
new BoundedOutOfOrdernessTimestampExtractor<MyElement>(Time.seconds(10)) {
@Override
public long extractTimestamp(final MyElement element) {
return element.getTimestamp();
}
});
With this definition and the code for BoundedOutOfOrdernessTimestampExtractor,
my understanding is that for each incoming element a watermark will be
generated that is 10 seconds behind the current timestamp. If any the end
time of any of the sliding windows is earlier that an emitted watermark that
(or those) windows will fire initiating a processing on the window(s). Is
this correct?
Paul
