title: Linux kill subproccess of already stop parent
body: <p>I am a Linux starter. 
  I have an multi threads application running on server. To stop the app, I executed command <code>application_name stop</code>. The app have been stopped. But later I realized its sub processes still running and process on my database. Because there are other applications can not be stopped on server, so I can not restart it. What can I do to kill these sub processes without restarting server?</p>