带PHP应用程序和用户会话的NodeJS

I have a PHP application (with Symfony2) and I need to let my users talk, and other tings, in real time (with socket.IO). Let's focus on the chat mechanism : A logged user can talk with an other logged user (logged with FOSUserBundle in Symfony). When the user sent a message, it must be saved in MySQL and sent in real time to the other user. So the message is linked to two users (a sender and a receiver) in my MySQL database.I have a PHP application (with Symfony2) and I