I'm having a problem with Nifi 1.5.0 installed on HDP 2.6.4. Beeline processes (launched by ExecuteStreamCommand and bash scripts) after they have actually finished are left hanging without ever being killed.
It is important that the script you're invoking always will terminate on its own. NiFi cannot reliably kill threads that it has handed out to components. The community has a feature in progress which will provide a solution to work around these cases but the real solution is to ensure that the invoked stream command always terminates properly.