session设置代码：session换用redis代替mongodb

   var session = require('express-session');  var redis = require('redis');
  var RedisStore = require('connect-redis')(session);
  var client = redis.createClient(80, 'redis.duapp.com', {"no_ready_check":true});
 client.on("error", function (err) {
 console.log("Error " + err);
});
 / /*数据库连接信息host,port,user,pwd,dbname(可查询数据库详情页)*/
 var username = 'UrtgxzMPVigNEyOQF7yzg7C9';          // 用户名（API KEY）
var password = '1e0jDqkZ7fUwNGFD5LzwPY4YAQURFGYM';  // 密码（Secret KEY）
var db_host = 'redis.duapp.com';   
var db_port = 80;
var db_name = 'QTQTzJQhMKcabjpSTIEX';               // 数据库名
console.log(db_host);
console.log(db_port);
var options = {"no_ready_check":true};

// 建立连接后，在进行集合操作前，需要先进行auth验证

client.auth(username + '-' + password + '-' + db_name);
 app.use(session({
secret: config.session_secret,
key: 'sid',
store: new RedisStore({
 client:client
}),
resave: true,
saveUninitialized: true
}