What to choose for writing a real-time 2D game server?

Question

Game development

Good afternoon.
For the sake of interest and knowledge of new technologies, I want to write regular checkers. I understand that their darkness does not scare :)
I will do it on Unity. I would like to make the game multiplayer - 2 players will be able to communicate over the network and play. Accordingly, this same server is needed. And the question is - what to write on? I only know PHP and MySQL.
Server tasks:
storage of data about the field, about moves, about players and about the game;
permanent connection with sending data to each player;
the ability to reconnect to the game after disconnection.
I look towards Node.JS and Socket.IO. Perhaps someone will advise something else with the argument? I will also not refuse links to useful materials. And in general from all sorts of comments.

Answer 1

There is such an option (with links to three copyright articles on Habré).
Book on sockets in PHP here .

Answer 2

I have no idea what I'm talking about, but if you're going to be doing action, sockets are a must.

Answer 3

> Looking towards Node.JS and Socket.IO
More Look at Golang and golem

Answer 4

As far as I can imagine, the server can be implemented in the Unity project itself www.paladinstudios.com/2013/07/10/how-to-create-an...