Nodejs Post请求报socket hang up错误的解决办法

var querystring = require('querystring')
  , http = require('http');

var data = querystring.stringify({
  info:'hi',
  test:5
});

var opt = {
  hostname:'www.test.com',
  port :9094,
  path:'/perationSqlQuery',
  method: 'POST',
  headers: {  
    'Content-Type':'application/x-www-form-urlencoded',
    'Content-Length': data.length 
  }
};

var req = http.request(opt, function (res) { 
  res.on('data', function (data) {
    console.log(data.toString());
  });
});
req.on('error', function(e) {
  console.log('problem with request: ' + e.message);
});
req.write(data);
req.end();