replica set connection with nodejs native

rs-connect.js

/**
 * MongoDB NodeJS Driver Production Connection Example
 *
 * Copyright (c) 2015 ObjectLabs Corporation
 * Distributed under the MIT license - http://opensource.org/licenses/MIT
 */

var MongoClient = require('mongodb').MongoClient;

/**
 * The following example uses node-mongodb-native 2.0.21 to connect to a MongoDB deployment using the options we have
 * found most appropriate to production applications. This example supports both replica set and SSL connections.
 *
 * For demonstration purposes, configuration is hard-coded; in practice, configuration should be externalized
 * e.g. into a file or environment variables.
 */

/**
 * Your deployment's URI in the standard format (http://docs.mongodb.org/manual/reference/connection-string/).
 *
 * The URI can be found via the MongoLab management portal (http://docs.mongolab.com/connecting/#connect-string).
 *
 * If you are using a PaaS add-on integration e.g. via Heroku, the URI is usually available via an environment variable,
 * often named "MONGOLAB_URI". Consult the documentation for the add-on you are using.
 */
var mongolab_uri = "mongodb://<dbUser>:<dbPassword>@<host1>:<port1>,<host2>:<port2>/<dbName>?replicaSet=<replicaSetName>";

/**
 * Pass the following keyword arguments to ensure proper production behavior:
 *
 *  autoReconnect     True to reconnect on error
 *
 *  keepAlive         Enabled (1) to ensure idle connections are kept alive in the presence of a firewall.
 *
 *  connectTimeoutMS  30 s to allow for PaaS warm-up; adjust down as needed for faster failures. For more, see docs:
 *                    http://docs.mongolab.com/timeout/#connection-timeout
 *
 *  socketTimeoutMS   No timeout (0) to allow for long-running operations
 *                    (http://docs.mongolab.com/timeout/#socket-timeout).
 *
 * See Nodejs Native docs for more details about the connection options:
 *
 *   http://mongodb.github.io/node-mongodb-native/2.0/api/MongoClient.html
 */
var options = {
    server: {
        socketOptions: {
            autoReconnect: true,
            keepAlive: 1,
            connectTimeoutMS: 30000,
            socketTimeoutMS: 0
        }
    },
    replSet: {
        socketOptions: {
            keepAlive: 1,
            connectTimeoutMS: 30000,
            socketTimeoutMS: 0
        }
    }
}

MongoClient.connect(mongolab_uri, options, function(err, db){
    if(err){
        console.log(err);
    } else {
        db.collections(function(err, collections) {
            collections.forEach(function(coll) {
                console.log(coll.s.name);
            });
        });
    }
});