When you say stopping the service for an instant you must mean pausing its execution or at least its IO. Actually stopping the service can’t be guaranteed to take an instant. It can’t be guaranteed to start in an instant. Worst of all, it can’t even be guaranteed that it’ll be able to start again. When I say stopping I mean sysemctl stop or docker stop or pkill etc. In other words delivering an orderly, graceful kill signal and waiting for the process/es to stop execution.