Hi all,
I am a little confused with the following windows operation. Here's the
code,
val senv = StreamExecutionEnvironment.getExecutionEnvironment
senv.setParallelism(1)
val data = senv.fromElements("hello world", "hello flink", "hello hadoop")
data.flatMap(line => line.split("\\s"))
.map(w => (w, 1))
.keyBy(0)
.countWindow(2, 1)
.sum(1)
.print("******************")
senv.execute()
And this is the output:
******************> (hello,1)
******************> (world,1)
******************> (hello,2)
******************> (flink,1)
******************> (hello,2)
******************> (hadoop,1)
As my understanding, here we have 3 windows.
window 1
(hello, world)
window 2
(hello, world)
(hello, flink)
window 3
(hello flink)
(hello hadoop)
So for the first window, we have output (hello, 1) (world, 1)
for the second window we should output (hello, 2), (world,1 ), (flink, 1)
for the third window we should have output (hello, 2), (flink, 1), (hadoop, 1)
But as you can see, in the above I get different result, do I
misunderstand the window ? Could anyone help me to understand that ?
Thanks
