In 1.2-SNAPSHOT, EventTimeSessionWindows are not firing untill the whole stream is processed

[Yassine MARZOUGUI]

Hi all,

With 1.1-SNAPSHOT, EventTimeSessionWindows fire as soon as the windows
boundaries are detected, but with 1.2-SNAPDHOT the state keeps increasing
in memory and the windows results are not emitted until the whole stream is
processed. Is this a temporary behaviour due to the developments in
1.2-SNAPSHOT, or a bug?

I am using a code similar to the follwoing:

env.setParallelism(1);

DataStream<T> sessions = env
    .readTextFile()
    .flatMap()
    .assignTimestampsAndWatermarks(new AscendingTimestampExtractor<>())
    .keyBy(1)
    .window(EventTimeSessionWindows.withGap(Time.minutes(5)))
    .apply().setParallelism(32)

sessions.flatMap(flatMapFunction1).setParallelism(32).writeAsCsv();
sessions.flatMap(flatMapFunction2).setParallelism(32).writeAsCsv();

Best,
Yassine