title: Rails 5 - Action Cable - list of connected users
body: <p>I'm starting with Rails 5 and Action Cable and I would like to display a list of names of all connected registered users (something like facebook's green circle). <br><br>
  I managed to get the name of the user, but now I'm thinking what's the best way to store them. In node I would simply in an array on server, but as I know that is not possible in ActionCable. <br></p>
  
  <p>What is the most effective way to do this?
  Storing them in database (postgres, redis)?</p>