The watermark delay defines threshold time for a delayed event to be accumulated into a data group.
Watermark delay is a threshold where you can specify the duration at which late arriving data can be grouped and processed. If an event data arrives within the threshold time, the data is processed, and the data is accumulated into the corresponding data group.
The window port specifies the column that contains the timestamp values based on which you can group the events. The accumulated data contains the timestamp value. Use the Window Port column to group the event time data that arrives late.
For more information, see
Informatica Big Data Streaming 10.2.2 User Guide