--在实际探讨前，先给出下面一个可能过的解决方案。

详细可见：http://blog.fens.me/nodejs-core-cluster/

<span style="font-size:18px;">var cluster = require('cluster'),
    numCPUs = require('os').cpus().length;
this.port=8001;

if (cluster.isMaster) {
    console.log(' num=' + numCPUs);
    for (var i = 0; i < numCPUs / 2; i++) {
        cluster.fork();
    }
    cluster.on('listening', function (worker, address) {
    });

} else if (cluster.isWorker) {
    http.createServer(exp).listen(this.port, function () {
        console.log(' server listening on = port='+ this.port);
    });
}</span>

Multiprocessor Deployment: Using a Proxy

参阅：http://www.tehnrd.com/host-multiple-node-js-apps-on-the-same-subdomain-with-heroku/

           和《learn nodejs》P220

 最容易的：每个核跑一个node进程。就这样ko。 

 假设我们的servers-list是长这样的，服务器是在81-83口监听。

{ "servers": [