Windowed operator configuration
Because we are developing an application for a taxi driver looking for passengers, we are only interested in the last few minutes of data, to have a good advice for the driver where to look. We are accumulating the data in 5-minute sliding windows that slide by 1 minute so that we always use the data from the past 5 minutes for our service. In Application.java:
KeyedWindowedOperatorImpl<String, Double, MutableDouble, Double> windowedOperator
= new KeyedWindowedOperatorImpl<>();
// 5-minute windows slide by 1 minute
windowedOperator.setWindowOption(new WindowOption.TimeWindows(Duration.standardMinutes(5)).slideBy(Duration
.standardMinutes(1)));
// Because we only care about the last 5 minutes, lateness horizon
// is set to 4 minutes since the watermark is set to one minute before
// the latest timestamp.
windowedOperator.setAllowedLateness(Duration.standardMinutes(4)); We are now setting the accumulation to be a SumDouble, which...
