Hey Flink users,

I wanted to see if I could get some insight on what the heap memory profile of 
my stream app should look like vs my expectation. My layout consists of a 
sequence of FlatMaps + Maps, feeding a pair of 5 minute 
TumblingEventTimeWindows, intervalJoined, into a 24 hour (per 5 minute) 
SlidingEventTimeWindow, then intervalJoined again, back into the first set of 
FlatMaps. The data flow works as expected, and the reports I am generated in 
the last join appear to be correct, and contain info from the 24 hour sliding 
window.

My understanding is that while all these windows build their memory state, I 
can expect heap memory to grow for the 24 hour length of the 
SlidingEventTimeWindow, and then start to flatten as the t-24hr window frames 
expire and release back to the JVM. What is actually happening is when a 
constant data source feeds the stream, the heap memory profile grows linearly 
past the 24 hour mark. Could this be a result of a misunderstanding of how the 
window’s memory states are kept, or is my assumption correct, and it is more 
likely I have a leak somewhere?

Thanks as always
Chris


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