Socket.io服务器到服务器（发送消息到特定服务器）

Question

我有一个特定的情况。我有连接到服务器A的客户端（浏览器）。服务器A连接到服务器B和C.当客户端向服务器A发送消息时，我需要将消息发送到特定服务器，这意味着服务器B或C之一，而不是两个都。一般来说，我需要在服务器之间进行分离通信，但我只能广播通信。从服务器A到另一台服务器的消息不能在所有连接的服务器上看到。

如何将消息直接发送到其中一台服务器？这是我的服务器代码片段。我只是更改每个服务器的端口并连接它们。

// Load requirements 
var PORT = process.env.PORT || 8080;//just change port for other servers 
var express = require("express"); 
var app = express(); 
var http = require("http").Server(app); 
var io = require("socket.io")(http); 

app.use(express.static(__dirname + '/public')); 

var client = require('socket.io-client'); 

var socket1 = client.connect('http://localhost:8081', { reconnect: true });//connection to server B 
var socket2 = client.connect('http://localhost:8082', { reconnect: true });//connection to server C 

// Add a connect listener 
io.on('connection', function (socket) { 
    console.log('Client connected.'); 
//when server receive message from client 
    socket.on('message_from_browser', function (message) { 
     console.log("Message from browser broadcasted: " + message.text); 
     var updated_message = { 
      text: message.text, 
      port: PORT 
     }; 

     // send message to server B 
     socket1.emit('server_message', updated_message);//send message to server B 
    }); 

    // Disconnect listener 
    socket.on('disconnect', function() { 
     console.log('Client disconnected.'); 
    }); 
}); 

socket1.on('connect', function() { 
    socket1.on('server_message', function (message) { 
     console.log('RECEIVED MESSAGE FROM ANOTHER SERVER ON PORT '+ message.port + ": " + message.text); 
    }); 
    //change server name 
    console.log('Connected to server B!'); 
}); 

socket2.on('connect', function() { 
    socket2.on('server_message', function (message) { 
     console.log('RECEIVED MESSAGE FROM ANOTHER SERVER ON PORT '+ message.port + ": " + message.text); 
    }); 
    //change server name 
    console.log('Connected to server C!'); 
}); 

http.listen(PORT, function (req, res) { 
    console.log("Server Started on port: " + PORT); 
}); 

Answer 1

您有变量名socket命名冲突。它被定义为您与服务器B的连接并作为您的.on('connection', function(socket) {...})回调中的参数。

为了解决这个问题，改变这种：

var socket = client.connect('http://localhost:8081', { reconnect: true });//connection to server B 
var socket2 = client.connect('http://localhost:8082', { reconnect: true });//connection to server C 

要这样：

var socket1 = client.connect('http://localhost:8081', { reconnect: true });//connection to server B 
var socket2 = client.connect('http://localhost:8082', { reconnect: true });//connection to server C 

而且，当时指的是服务器B连接，socket1，不socket。

命名socket变量已经被定义为这样的一个说法，所以你无法到达外socket变量时，它有一个名称冲突：

// Add a connect listener 
io.on('connection', function (socket) { 
    // socket variable name ^^^^^^ 
    console.log('Client connected.'); 
//when server receive message from client 
    socket.on('message_from_browser', function (message) { 
     console.log("Message from browser broadcasted: " + message.text); 
     var updated_message = { 
      text: message.text, 
      port: PORT 
     }; 

     // send message to server B 
     socket1.emit('server_message', updated_message);//send message to server B 
    }); 

    // Disconnect listener 
    socket.on('disconnect', function() { 
     console.log('Client disconnected.'); 
    }); 
}); 

并有传入服务器的消息，所以你不需要听众为socket1和socket2添加侦听器。

io.on('connect', function(socket1){ 
    socket1.on('server_message', function (message) { 
     console.log('RECEIVED MESSAGE FROM ANOTHER SERVER ON PORT '+ message.port + ": " + message.text); 
    }); 
}); 

io.on('connect', function(socket2){ 
    socket2.on('server_message', function (message) { 
     console.log('RECEIVED MESSAGE FROM ANOTHER SERVER ON PORT '+ message.port + ": " + message.text); 
    }); 
}); 

Answer 2

使用一个变量和CONFIGS跟踪别人的主机，尝试：

更新修复了一些bug：

// Load requirements 
var PORT = process.env.PORT || 8081;//just change port for other servers 
var express = require("express"); 
var app = express(); 
var http = require("http").Server(app); 
var io = require("socket.io")(http); 
var async = require('async'); // async is optional for this example ... 
var client = require('socket.io-client'); 

app.use(express.static(__dirname + '/public')); 

// save hosts here ... 
var otherServers = { 
    server1: { 
    url: 'http://localhost:8082' 
    }, 
    server2: { 
    url: 'http://localhost:8083' 
    }, 
}; 

// Add a connect listener 
io.on('connection', function (socket) { 
    console.log('Client connected.'); 
    //when server receive message from client 
    socket.on('message_from_browser', function (message) { 
     console.log("Message from browser broadcasted: " + message.text); 
     var updated_message = { 
     text: message.text, 
     port: PORT 
     }; 

     // choice how server will receive this message ... 
     // then send it 
     otherServers.server1.client.broadcast.emit('server_message', updated_message); 
    }); 

    // Disconnect listener 
    socket.on('disconnect', function() { 
     console.log('Client disconnected.'); 
    }); 
}); 

async.each(otherServers, function forEachOtherServer(otherServer, next) { 
    //connect to another server 
    otherServer.client = client.connect(otherServer.url, { reconnect: true }); 
    // to something more if need in every client connection ... 

    otherServer.client.on('connect', function (x) { 

    otherServer.client.on('server_message', function (message) { 
     console.log('RECEIVED MESSAGE FROM ANOTHER SERVER ON PORT '+ message.port + ": " + message.text); 
     //socket.broadcast.emit('message_from_server', message_server); 
    }); 
    console.log('Connected!'); 
    }); 

    next(); 
}, function afterConnectInAllServers(err) { 
    if (err) throw err; 
    // to something after connect in all servers ... 
}); 

http.listen(PORT, function (req, res) { 
    console.log("Server Started on port: " + PORT); 
});