title: Chat server using Nodejs & Socket.io : Best way to log conversations
body: <p>I'm using a Chat server with multiples rooms using nodejs and socket.io. I was wondering what is the best way to save all conversation ?</p>
  
  <p>I'm also using Mysql and Redis (session). I'm not sure that MySQL is a good choice since it will be overloaded and I need it to display other page contents.
  What about flat files ? This coulb be awesome, but isn't there some risk of having the file already opened while trying to save a new message ?</p>
  
  <p>Thank you</p>