Multiplayer game server with multiple node

Question

Say you're making a Counter-Strike server. We have a single lobby and multiple rooms in which game sessions occur.

I.E I have 3 node server, nginx load balancer, redis.

I'm using socket.io, with redis adapter, So I can emit messages to every clients on any server.

I can't understand one thing. For example I have something like this:

    var currentGames = {};


socket.on('createGame', function(gameName){
  var game = new Game();
  game.addPlayer(socket.id);


  currentGames.push();

  // ... Send to all clients, that game created and they can join
});

socket.on('joinGame', function(gameName){
  currentGames[gameName].addPlayer(socket.id);

  // ... Send to all players of this game, that player joined
});


socket.on('walk', function(gameName, coordinates){
   currentGames[socket.id].walk(player, coordinates);

   // ... Get all players positions and send to clients
});


class Game
{
  gameName;
  players = {};
  score;

  constructor(name){
    this.gameName = name;
  }

  addPlayer(player){
    players[name] = new Player(player);
  }

  walk(id, coordinates){
    this.players[id].updatePosition(coordinates);
  }  
}

class player
{
  id;
  life = 100;
  coordinates = {0,0,0};
  kills;
  death;

  constructor(id){
    this.id = id;
  }

  updatePosition(coords){
    this.coordinates = coords;
  }


}

I've just written this code, for example.

let, user_1 is on node-1 and user-2 is on node-2.

If user_1 creates game, instance will be created and saved on node-1.

so when user_2 receives information about game, which was created and he clicks a join button, client will send request to server and on node-2 there won't be the game instance, which user_1 created.

I hope, you will understand, what I'm talking (my English isn't good).

I guess, that currentGames object of game instances must be a global, for all nodes. But I don't know how.

Should I use redis or mongo or something else, for storing game information, instead of variable?

Am I going with wrong way?

score 0 · Answer 1 · answered May 25 '16 at 11:26

U should sync Game State in Redis, room and game instance, too.
I have some note :
+ Entity State - manage Game State, store and set, get Game information to Redis
+ Client State - each connection client have Client State and Sync with Entity State, each tick in Game loop, u check difference beetween Entity State and Client State and send it to Client and update Game Client

Multiplayer game server with multiple node

1 Answers1