pyflink.datastream.data_stream.WindowedStream.side_output_late_data#

WindowedStream.side_output_late_data(output_tag: OutputTag) → WindowedStream[source]#

Send late arriving data to the side output identified by the given OutputTag. Data is considered late after the watermark has passed the end of the window plus the allowed lateness set using allowed_lateness().

You can get the stream of late data using get_side_output() on the DataStream resulting from the windowed operation with the same OutputTag.

Example:

>>> tag = OutputTag("late-data", Types.TUPLE([Types.INT(), Types.STRING()]))
>>> main_stream = ds.key_by(lambda x: x[1]) \
...                 .window(TumblingEventTimeWindows.of(Time.seconds(5))) \
...                 .side_output_late_data(tag) \
...                 .reduce(lambda a, b: a[0] + b[0], b[1])
>>> late_stream = main_stream.get_side_output(tag)

New in version 1.16.0.