node reconnect.js YOUR_CONNECTION_STRING

reconnect-mongos.js

var mongo = require('mongodb');
console.log(mongo.version);


var uri = process.argv[1];

mongo.MongoClient.connect(uri, function (err, db) {
  if (err) throw err;

  var c = db.collection('test');
  c.insert({ testing: true }, function (err) {
    if (err) return done(err);
    test()
  })

  function test () {
    console.log('querying'); 
    c.findOne(console.log);
  }
  setInterval(test, 1000)

  function done (err) {
    if (err) console.error(err);
    db.close();
  }
})