我有一个在Rails和Backbone.js上运行的单页应用程序。我正在通过Redis使用Node.js将数据推送并同步到客户端。我正在尝试了解，保护和优化套接字通信。

使用console.log编写时，我看到一些日志行（console.log('Redis connection on ..')）正在重复（请参见下面的内容）。

有人能解释我为什么吗？通过我的代码实现，我是否不了解某些特定的Node.js行为？

这是我的Node.js代码：

var io = require('socket.io').listen(3003);
var redis = require('redis');
var cookie = require("cookie");
var redis_subs = redis.createClient(6379, "localhost");
var redis_auth = redis.createClient(6379, "localhost");
var authenticated = false;

var authentication_status = function (status) {
  if (status === true) {
    console.log('Authentication status is true.');
  }
  else {
    console.log('Authentication status is false.');
  }
  authenticated = status;
};

redis_subs.subscribe('application_channel');

io.configure(function () {
  io.set('authorization', function (data, callback) {
    console.log('Cross authentication...');
    if (data.headers.cookie) {
      data.cookie = cookie.parse(data.headers.cookie);
      data.sessionID = data.cookie['_validation_token_key'];
      redis_auth.hget(["sessionStore", data.sessionID], function (err, session) {
        if (err || !session) {
          console.log('Socket.io authorization say false');
          return callback(authentication_status(false), false);
        }
        else {
          data.session = JSON.parse(session);
          console.log('Socket.io authorization say true');
          return callback(authentication_status(true), true);
        }
      });
    }
    else {
      console.log('Socket.io authorization say false');
      return callback(authentication_status(false), false);
    }
  });
});

io.on('connection', function(socket){
    if (socket.handshake.session) {
      var user_socket_channel = socket.handshake.session['user_socket_channel']
      redis_subs.on('message', function(redis_channel, rawdata) {
        console.log('Redis connection on '+redis_channel);
        console.log('Handshaked Session, authenticated user. All channels allowed.');
        var data = JSON.parse(rawdata);
        if (data.channel) { var socket_channel = data.channel; }
        else { var socket_channel = user_socket_channel; }
        var rails_data = data.data;
        console.log('Socket.io emiting on ['+socket_channel+']')
        socket.emit(socket_channel, rails_data);
      });
    }
    else {
      redis_subs.on('message', function(redis_channel, rawdata) {
        console.log('Redis connection on '+redis_channel);
        console.log('No handshaked Session, unauthenticated user. Public channels allowed.');
        var data = JSON.parse(rawdata);
        var rails_data = data.data;
        console.log('Socket.io emiting on [public]')
        socket.emit('public', rails_data);
      });
    }
});

这是我测试的方式，以及日志变得重复的特定用例：

使用Web浏览器1（例如Firefox）在登录时加载页面；输出：

   info  - socket.io started
Cross authentication...
Socket.io authorization say true
Authentication status is true.
   debug - authorized
   info  - handshake authorized bJxm_IcWl2mKZT4Ed-kV
   debug - setting request GET /socket.io/1/websocket/bJxm_IcWl2mKZT4Ed-kV
   debug - set heartbeat interval for client bJxm_IcWl2mKZT4Ed-kV
   debug - client authorized for 
   debug - websocket writing 1::

加载正在用浏览器2注销的同一页面（例如：Chrome）

Cross authentication...
Socket.io authorization say false
Authentication status is false.
   debug - authorized
   info  - handshake unauthorized

通过page / browser1（Firefox）-> Rails-> Redis发送一些数据，输出：

Redis connection on application_channel
Handshaked Session, authenticated user. All channels allowed.
Socket.io emiting on [hLTYXuvP+13aQlIT9CZiYc1i9eg=]
   debug - websocket writing 5:::{"name":"hLTYXuvP+13aQlIT9CZiYc1i9eg=","args":[null]}

在浏览器2上重新加载页面（Chrome，已注销），仍在输出

Cross authentication...
Socket.io authorization say false
Authentication status is false.
   debug - authorized
   info  - handshake unauthorized

在浏览器1 / Firefox上重新加载页面，并通过页面和Rails将更多数据推送到Redis，输出：

Redis connection on application_channel
Handshaked Session, authenticated user. All channels allowed.
Socket.io emiting on [hLTYXuvP+13aQlIT9CZiYc1i9eg=]
Redis connection on application_channel
Handshaked Session, authenticated user. All channels allowed.
Socket.io emiting on [hLTYXuvP+13aQlIT9CZiYc1i9eg=]
   debug - websocket writing 5:::{"name":"hLTYXuvP+13aQlIT9CZiYc1i9eg=","args":[null]}

如您所见，事件被复制了，Redis侦听器现在捕获了两个连接。每次我重新加载page1 / Firefox时，它都会重复复制一次（3、4、5 …）。

我不了解这种行为。我想念什么？顺便说一句，你可以看到，我真的不明白或者Socket.io的目标configure，set authorization并且callback，返回真或假，如节点是伸手io.on('connection')和Redis的听众呢。