No data issued by flink window after a few hours

[? ??]

Hi all,
    I used flink window, and when the job begins, we could get the results of 
windiow.But there’re no results issued after a few hours.
    I found the job is still running and no errors, and the data not used 
window all can be issued.
    By the way, I used Flink 1.3.2 and ram to cache the distinct data about 
sliding window.

Yours,
    September