Add client dispatcher mode and server metrics

.gitignore

@@ -2,4 +2,4 @@ node_modules
 client-build
 build.txt
 config_build.json
-config_local.json
+config_local*

client/js/game.js

@@ -707,8 +707,15 @@ function(InfoManager, BubbleManager, Renderer, Map, Animation, Sprite, AnimatedT
             var self = this;
 
             this.client = new GameClient(this.host, this.port);
-            this.client.connect();
-
+            this.client.connect(true);
+
+            this.client.onDispatched(function(host, port) {
+                self.client.host = host;
+                self.client.port = port;
+                alert("host:"+host+ "  port:"+port);
+                self.client.connect(); // connect to actual game server
+            });
+
             this.client.onConnected(function() {
                 log.info("Connected to server "+self.client.host+":"+self.client.port);
 

client/js/gameclient.js

@@ -43,8 +43,8 @@ define(['player', 'entityfactory', 'lib/bison'], function(Player, EntityFactory,
         disable: function() {
             this.isListening = false;
         },
-
-        connect: function() {
+        
+        connect: function(dispatcherMode) {
             var url = "ws://"+ this.host +":"+ this.port +"/",
                 self = this;
 
@@ -55,25 +55,39 @@ define(['player', 'entityfactory', 'lib/bison'], function(Player, EntityFactory,
             } else {
                 this.connection = new WebSocket(url);
             }
-
-            this.connection.onopen = function(e) {
-                if(self.connected_callback) {
-                    self.connected_callback();
-                }
-            };
+
+            if(dispatcherMode) {
+                this.connection.onmessage = function(e) {
+                    var reply = JSON.parse(e.data);
 
-            this.connection.onmessage = function(e) {
-                self.receiveMessage(e.data);
-            };
-
-            this.connection.onerror = function(e) {
-                log.error(e, true);
-            };
-
-            this.connection.onclose = function() {
-                log.debug("Connection closed");
-                $('#container').addClass('error');
-            };
+                    if(reply.status === 'OK') {
+                        self.dispatched_callback(reply.host, reply.port);
+                    } else if(reply.status === 'FULL') {
+                        alert("BrowserQuest is currently at maximum player population. Please retry later.");
+                    } else {
+                        alert("Unknown error while connecting to BrowserQuest.");
+                    }
+                };
+            } else {
+                this.connection.onopen = function(e) {
+                    if(self.connected_callback) {
+                        self.connected_callback();
+                    }
+                };
+
+                this.connection.onmessage = function(e) {
+                    self.receiveMessage(e.data);
+                };
+
+                this.connection.onerror = function(e) {
+                    log.error(e, true);
+                };
+
+                this.connection.onclose = function() {
+                    log.debug("Connection closed");
+                    $('#container').addClass('error');
+                };
+            }
         },
 
         sendMessage: function(json) {
@@ -339,6 +353,10 @@ define(['player', 'entityfactory', 'lib/bison'], function(Player, EntityFactory,
                 this.blink_callback(id);
             }
         },
+
+        onDispatched: function(callback) {
+            this.dispatched_callback = callback;
+        },
 
         onConnected: function(callback) {
             this.connected_callback = callback;

server/config.json

@@ -3,5 +3,6 @@
     "debug_level": "info",
     "nb_players_per_world": 200,
     "nb_worlds": 5,
-    "map_filepath": "./server/maps/world_server.json"
+    "map_filepath": "./server/maps/world_server.json",
+    "metrics_enabled": false
 }

server/config_local.json-dist

@@ -3,5 +3,6 @@
     "debug_level": "debug",
     "nb_players_per_world": 200,
     "nb_worlds": 5,
-    "map_filepath": "./server/maps/world_server.json"
+    "map_filepath": "./server/maps/world_server.json",
+    "metrics_enabled": false
 }

server/js/main.js

@@ -1,5 +1,6 @@
 
-var fs = require('fs');
+var fs = require('fs'),
+    Metrics = require('./metrics');
 
 
 function main(config) {
@@ -8,6 +9,7 @@ function main(config) {
         Log = require('log'),
         _ = require('underscore'),
         server = new ws.MultiVersionWebsocketServer(config.port),
+        metrics = config.metrics_enabled ? new Metrics(config) : null;
         worlds = [];
 
     switch(config.debug_level) {
@@ -19,32 +21,71 @@ function main(config) {
             log = new Log(Log.INFO); break;
     };
 
+    log.info("Starting BrowserQuest game server...");
+
     server.onConnect(function(connection) {
-        var world = _.detect(worlds, function(world) {
-            return world.playerCount < config.nb_players_per_world;
-        });
-        if(world) {
-            world.connect_callback(new Player(connection, world));
+        var world, // the one in which the player will be spawned
+            connect = function() {
+                if(world) {
+                    world.connect_callback(new Player(connection, world));
+                    connection.send("go");
+                }
+            };
+
+        if(config.metrics_enabled) {
+            metrics.getOpenWorldCount(function(open_world_count) {
+                // choose the least populated world among open worlds
+                world = _.min(_.first(worlds, open_world_count), function(w) { return w.playerCount; });
+                connect();
+            });
+        }
+        else {
+            // simply fill each world sequentially until they are full
+            world = _.detect(worlds, function(world) {
+                return world.playerCount < config.nb_players_per_world;
+            });
+            connect();
         }
     });
 
     server.onError(function() {
         log.error(Array.prototype.join.call(arguments, ", "));
     });
+
+    var onPopulationChange = function() {
+        metrics.updatePlayerCounters(worlds);
+        metrics.updateWorldDistribution(getWorldDistribution(worlds));
+    };
 
     _.each(_.range(config.nb_worlds), function(i) {
         var world = new WorldServer('world'+ (i+1), config.nb_players_per_world, server);
         world.run(config.map_filepath);
         worlds.push(world);
+
+        if(config.metrics_enabled) {
+            world.onPlayerAdded(onPopulationChange);
+            world.onPlayerRemoved(onPopulationChange);
+        }
     });
 
     server.onRequestStatus(function() {
-        var status = [];
-        _.each(worlds, function(world) {
-            status.push(world.playerCount);
+        return JSON.stringify(getWorldDistribution(worlds));
+    });
+
+    if(config.metrics_enabled) {
+        metrics.ready(function() {
+            onPopulationChange(); // initialize all counters to 0 when the server starts
         });
-        return JSON.stringify(status);
+    }
+}
+
+function getWorldDistribution(worlds) {
+    var distribution = [];
+
+    _.each(worlds, function(world) {
+        distribution.push(world.playerCount);
     });
+    return distribution;
 }
 
 function getConfigFile(path, callback) {
@@ -58,9 +99,17 @@ function getConfigFile(path, callback) {
     });
 }
 
+var defaultConfigPath = './server/config.json',
+    customConfigPath = './server/config_local.json';
+
+process.argv.forEach(function (val, index, array) {
+    if(index === 2) {
+        customConfigPath = val;
+    }
+});
 
-getConfigFile('./server/config.json', function(defaultConfig) {
-    getConfigFile('./server/config_local.json', function(localConfig) {
+getConfigFile(defaultConfigPath, function(defaultConfig) {
+    getConfigFile(customConfigPath, function(localConfig) {
         if(localConfig) {
             main(localConfig);
         } else if(defaultConfig) {

server/js/metrics.js

@@ -0,0 +1,66 @@
+
+var cls = require("./lib/class"),
+    _ = require("underscore"),
+    memcache = require("memcache");
+
+module.exports = Metrics = Class.extend({
+    init: function(config) {
+        var self = this;
+
+        this.config = config;
+        this.client = new memcache.Client(config.memcached_port, config.memcached_host),
+        this.client.connect();
+        this.isReady = false;
+
+        this.client.on('connect', function() {
+            log.info("Metrics enabled: memcached client connected to "+config.memcached_host+":"+config.memcached_port);
+            self.isReady = true;
+            if(self.ready_callback) {
+                self.ready_callback();
+            }
+        });
+    },
+
+    ready: function(callback) {
+        this.ready_callback = callback;
+    },
+
+    updatePlayerCounters: function(worlds) {
+        var self = this,
+            config = this.config,
+            numServers = _.size(config.game_servers),
+            playerCount = _.reduce(worlds, function(sum, world) { return sum + world.playerCount; }, 0);
+
+        if(this.isReady) {
+            // Set the number of players on this server
+            this.client.set('player_count_'+config.server_name, playerCount, function() {
+                var total_players = 0;
+
+                // Recalculate the total number of players and set it
+                _.each(config.game_servers, function(server) {
+                    self.client.get('player_count_'+server.name, function(error, result) {
+                        var count = result ? parseInt(result) : 0;
+
+                        total_players += count;
+                        numServers -= 1;
+                        if(numServers === 0) {
+                            self.client.set('total_players', total_players);
+                        }
+                    });
+                });
+            });
+        } else {
+            log.error("Memcached client not connected");
+        }
+    },
+
+    updateWorldDistribution: function(worlds) {
+        this.client.set('world_distribution_'+this.config.server_name, worlds);
+    },
+
+    getOpenWorldCount: function(callback) {
+        this.client.get('world_count_'+this.config.server_name, function(error, result) {
+            callback(result);
+        });
+    }
+});

server/js/player.js

@@ -23,8 +23,6 @@ module.exports = Player = Character.extend({
         this.lastCheckpoint = null;
         this.formatChecker = new FormatChecker();
 
-        this.server.incrementPlayerCount();
-
         this.connection.listen(function(message) {
             var action = parseInt(message[0]);
 
@@ -206,7 +204,6 @@ module.exports = Player = Character.extend({
             if(self.exit_callback) {
                 self.exit_callback();
             }
-            self.server.decrementPlayerCount();
         });
     },
 

server/js/worldserver.js

@@ -1,6 +1,5 @@
 
-var sys = require("sys"),
-    cls = require("./lib/class"),
+var cls = require("./lib/class"),
     _ = require("underscore"),
     Log = require('log'),
     Entity = require('./entity'),
@@ -61,7 +60,11 @@ module.exports = World = cls.Class.extend({
         });
 
         this.onPlayerEnter(function(player) {
-            log.info(player.name + " has joined "+ this.id);
+            log.info(player.name + " has joined "+ self.id);
+
+            if(!player.hasEnteredGame) {
+                self.incrementPlayerCount();
+            }
 
             // Number of players in this world
             self.pushToPlayer(player, new Messages.Population(self.playerCount));
@@ -108,7 +111,16 @@ module.exports = World = cls.Class.extend({
             player.onExit(function() {
                 log.info(player.name + " has left the game.");
                 self.removePlayer(player);
+                self.decrementPlayerCount();
+
+                if(self.removed_callback) {
+                    self.removed_callback();
+                }
             });
+
+            if(self.added_callback) {
+                self.added_callback();
+            }
         });
 
         // Called when an entity is attacked by another entity
@@ -209,6 +221,14 @@ module.exports = World = cls.Class.extend({
         this.enter_callback = callback;
     },
 
+    onPlayerAdded: function(callback) {
+        this.added_callback = callback;
+    },
+
+    onPlayerRemoved: function(callback) {
+        this.removed_callback = callback;
+    },
+
     onRegenTick: function(callback) {
         this.regen_callback = callback;
     },