var MongoClient = require('mongodb').MongoClient
    , format = require('util').format;
MongoClient.connect('mongodb://127.0.0.1:27030,127.0.0.1:27031,127.0.0.1:27032/beagles', 
	{
	  replSet: {
	    connectWithNoPrimary:true,
	    replicaSet: 'beagles',
	    readPreference: 'primaryPreferred'
	  }
	}, 
	function (err, db) {
	    if (err) {
	        throw err;
	    } else {
	        console.log("successfully connected to the database");	        
	    }

	    var collection = db.collection('dogs');

	    try {
		    console.log("before insert");
		    db.createCollection("cats", {w: 1, wtimeout: 1000}, function(err, collection) {
		    	console.log(err);
                        db.close();
		    })
		    console.log("after insert");
		}
		catch(e) { throw e; }
	}
);