如何在socket.io中重用redis连接？

Question

这是我的代码使用socket.io作为WebSocket和后端与pub/sub redis.

var io = io.listen(server),
    buffer = [];

var redis = require("redis");

var subscribe = redis.createClient();  **<--- open new connection overhead**

io.on('connection', function(client) {

    console.log(client.request.headers.cookie);

    subscribe.get("..", function (err, replies) {

    });

    subscribe.on("message",function(channel,message) {

        var msg = { message: [client.sessionId, message] };
        buffer.push(msg);
        if (buffer.length > 15) buffer.shift();
        client.send(msg);
    });

    client.on('message', function(message){
    });

    client.on('disconnect', function(){
        subscribe.quit();
    });
});

每个新的io请求都将创建新的redis连接.如果有人用100个标签打开浏览器,那么redis客户端将打开100个连接.它看起来不太好看.

如果cookie相同,是否可以重用redis连接？因此,如果有人打开许多浏览器标签,也将其视为开放1连接.

Answer 1

实际上,如果要在"连接"事件上实例化客户端,则只为每个连接创建一个新的redis客户端.创建聊天系统时我更喜欢创建三个redis客户端.一个用于发布,订阅,一个用于将值存储到redis中.

例如:

var socketio = require("socket.io")
var redis = require("redis")

// redis clients
var store = redis.createClient()
var pub = redis.createClient()
var sub = redis.createClient()

// ... application paths go here

var socket = socketio.listen(app)

sub.subscribe("chat")

socket.on("connection", function(client){
  client.send("welcome!")

  client.on("message", function(text){
    store.incr("messageNextId", function(e, id){
      store.hmset("messages:" + id, { uid: client.sessionId, text: text }, function(e, r){
        pub.publish("chat", "messages:" + id)
      })
    })
  })

  client.on("disconnect", function(){
    client.broadcast(client.sessionId + " disconnected")
  })

  sub.on("message", function(pattern, key){
    store.hgetall(key, function(e, obj){
      client.send(obj.uid + ": " + obj.text)
    })
  })

})