MongodStarter runtime = MongodStarter.getDefaultInstance();
int port = Network.getFreeServerPort();
IMongodConfig mongodConfig = new MongodConfigBuilder()
.version(Version.Main.PRODUCTION)
.net(new Net(port, Network.localhostIsIPv6())).build();
// Store Mongo server "host:port" in Hadoop configuration
// so that MongoStore will be able to get it latter
conf.set(MongoStore.PROP_MONGO_SERVERS, "127.0.0.1:" + port);