Run pipeline without flushing all the windows about flink-spector

[lofifnc]

I have tried implementing this feature. In fact it should be the default behaviour that no max timestamp should be emitted. There is a flushOpenWindowsOnTermination() method which enables the emit of a Long.MAX_VALUE.
But if I remember correctly the engine itself seems to emit a max watermark. I have to debug this myself and get back to you.

[lofifnc]

The framework will emit a max watermark if the source has not been cancelled. Which is the case here because the source just runs out of input and stops. There seems to be no way to stop the framework from emitting the watermark. The only solution would be to block the source and then notify some listener outside of the framework to cancel the job/cluster (which seems a little bit over engineered).
I think I have to discuss this with the Flink guys.