DrainingControl.isShutdown memory leak

[ilinandrii]

Versions used

2.0.5
master

Akka version:
2.5.32

Expected Behavior

Calls to DrainingControl.isShutdown method don't create additional future callbacks that occupy memory and in a long run for infinite streams lead to OOM

Actual Behavior

I'm using DrainingControl.isShutdown().isCompleted() for consumer health checks.
Health check calls lead to corresponding isShutdown calls on all running consumers, which in turn create new future callbacks with .flatMap.
The number of callbacks constantly growth and because all of my consumers are infinite streams those callbacks are never resolved and occupy heap until OOM is reached after a very long run.
I've workaround this by caching first call on isShutdown and calling isCompleted on returned future on each health check call, however it would be nice to have it fixed in a library.

[ennru]

Thank you for reporting this. Recreating the future should not be necessary and must be avoided.
Would you be in a position to suggest a fix?