Problem to exit/kill or stop container or docker service

I start working with docker and after build an application that can run insode a docker
after a few minutes it looks there is a performance issue and the whole docker system is hang.

I can’t exist or stop/kill the container from the docker neither stop the docker service.
I order to bring back docker I need to restart the system.
I am currently on version 1.12.1

Any idea how to stop/restart it without restart the whole system ?
How can I be sure I allocate the correct resources to my container ?
How to debug such a problem ?

I have no idea how I can continue from here , as it looks docker can’t host my application.