关于 socket.io 负载均衡问题

关于socket.io 负载均衡问题，参考官网Using multiple nodes:http://socket.io/docs/using-multiple-nodes/, 我设置如下：

var io = require('socket.io').listen(8891);

var port=6379;
var host='localhost';
var pwd = '******';

var redis = require('redis').createClient;
var adapter = require('socket.io-redis');
var pub = redis(port, host, { auth_pass: pwd });
var sub = redis(port, host, { detect_buffers: true, auth_pass: pwd });
io.adapter(adapter({ pubClient: pub, subClient: sub }));

关于这个adapter 总是报错：

io.adapter(adapter({ pubClient: pub, subClient: sub }));
   ^
TypeError: undefined is not a function
at Object.<anonymous> (/home/team/project/ylx/sync-svc/sync-server_8891.js:18:4)
at Module._compile (module.js:462:26)
at Object.Module._extensions..js (module.js:480:10)
at Module.load (module.js:357:32)
at Function.Module._load (module.js:312:12)
at Function.Module.runMain (module.js:503:10)
at startup (node.js:132:16)
at node.js:817:3

我的socket.io版本0.9.17，其他版本见下方：

├─┬ hiredis@0.3.0
│ ├── bindings@1.2.1
│ └── nan@1.5.3
├── redis@0.12.1
├─┬ socket.io@0.9.17
│ ├── base64id@0.1.0
│ ├── policyfile@0.0.4
│ ├── redis@0.7.3
│ └─┬ socket.io-client@0.9.16
│   ├─┬ active-x-obfuscator@0.0.1
│   │ └── zeparser@0.0.5
│   ├── uglify-js@1.2.5
│   ├─┬ ws@0.4.32
│   │ ├── commander@2.1.0
│   │ ├── nan@1.0.0
│   │ ├── options@0.0.6
│   │ └── tinycolor@0.0.1
│   └── xmlhttprequest@1.4.2
└─┬ socket.io-redis@0.1.4
  ├── debug@0.7.4
  ├─┬ msgpack-js@0.3.0
  │ └─┬ bops@0.0.7
  │   ├── base64-js@0.0.2
  │   └── to-utf8@0.0.1
  ├── redis@0.10.1
  ├─┬ socket.io-adapter@0.3.1
  │ ├─┬ debug@1.0.2
  │ │ └── ms@0.6.2
  │ ├── object-keys@1.0.1
  │ └─┬ socket.io-parser@2.2.2
  │   ├── benchmark@1.0.0
  │   ├── component-emitter@1.1.2
  │   ├── debug@0.7.4
  │   ├── isarray@0.0.1
  │   └── json3@3.2.6
  └── uid2@0.0.3

对于此类问题求解决方案~