Node JS : ZooKeeperError: Connection Not Established

I am new to node-js cloud platform. My requirement is to register different services having different port register with centralised discovery-service, so that if I want to communicate with another service I can get information like port no, path just by sending service name to discovery client. Currently I am using 'node-service-discovery' module for my requirement. I have no Idea how exactly to use this module.

I have a service running on port 9001 trying to register using 'Service Register' to 'Service Discovery'.

Following is Error I am facing.

        throw new ZooKeeperError('Connection Not Established');
        ^

ZooKeeperError: Connection Not Established
    at Ranger.getZkClient (C:\Program Files\nodejs\node_modules\npm\node_modules\node-service-discovery\lib\Ranger.js:96:15)
    at createServiceBasePath (C:\Program Files\nodejs\node_modules\npm\node_modules\node-service-discovery\lib\ServiceDiscovery.js:58:14)
    at nextTask (C:\Program Files\nodejs\node_modules\npm\node_modules\async\dist\async.js:5021:18)
    at Object.waterfall (C:\Program Files\nodejs\node_modules\npm\node_modules\async\dist\async.js:5024:9)
    at ServiceDiscovery.registerService (C:\Program Files\nodejs\node_modules\npm\node_modules\node-service-discovery\lib\ServiceDiscovery.js:48:11)
    at Object.<anonymous> (C:\NODE POC\Node-Service\ServiceRegistration.js:47:18)
    at Module._compile (module.js:409:26)
    at Object.Module._extensions..js (module.js:416:10)
    at Module.load (module.js:343:32)
    at Function.Module._load (module.js:300:12)

Following is My Code.

ServiceDiscovery.js

'use strict';

var Ranger                  = require('C:/Program Files/nodejs/node_modules/npm/node_modules/node-service-discovery').Ranger;
var ServiceInstanceBuilder  = require("C:/Program Files/nodejs/node_modules/npm/node_modules/node-service-discovery").ServiceInstanceBuilder;
var ServiceDiscoveryBuilder = require('C:/Program Files/nodejs/node_modules/npm/node_modules/node-service-discovery').ServiceDiscoveryBuilder;
var ServiceInstance = require('C:/Program Files/nodejs/node_modules/npm/node_modules/node-service-discovery/lib/ServiceInstance');
//Create a Ranger Client
var rangerClient = Ranger.newClient(process.env.ZK_CONNECTION_STRING || '127.0.0.1:2181');
/** start emits 'connected' event. You can initialize following things after the event
 *  Eg: rangerClient.once('connected') { //initialize following code }
 */
rangerClient.start();
var healthCheck = function () {
        var isHealthy = true;
        return {
            isHealthy: function () {
                return isHealthy;
            },
            setStatus: function (status) {
                isHealthy = status;
            }
        }
};
var instanceHealthCheck = healthCheck();
/**
 * Create the Service Discovery Instance
 *
 * process.env.refreshInterval is the interval to check for the updation of nodes in ZK.
 */
var serviceInstance = new ServiceInstance("my-service", "localhost", 9001, "development", [instanceHealthCheck]);
console.log(JSON.stringify(serviceInstance.getData()));
var serviceDiscovery = ServiceDiscoveryBuilder
        .builder()
        .client(rangerClient)
        .serviceInstance(serviceInstance)
        .basePath('services')
        .refreshInterval(10000)
        .build();
// Create the instance provider (selectionStrategy: 'RoundRobin' or 'Random')
var instanceProvider = serviceDiscovery
        .instanceProviderBuilder()
        .serviceName('dependent-service')
        .selectionStrategy('RoundRobin')
        .build()
//init the provider, it adds watcher, adds periodic polling and gets instance data for first time
instanceProvider.init(function(error) {
    //check for error her
    console.log('Error in ServiceDiscovery.');
    console.log(error);
});
// Get an instance. The returned value will have 'data' model specified above
console.log('getInstance: '+instanceProvider.getInstance());
module.exports.serviceDiscovery = serviceDiscovery;

ServiceRegister.js:

'use strict';
var Ranger                  = require('C:/Program Files/nodejs/node_modules/npm/node_modules/node-service-discovery').Ranger;
var ServiceInstanceBuilder  = require("C:/Program Files/nodejs/node_modules/npm/node_modules/node-service-discovery").ServiceInstanceBuilder;
var ServiceDiscoveryBuilder = require('C:/Program Files/nodejs/node_modules/npm/node_modules/node-service-discovery').ServiceDiscoveryBuilder;
var ServiceDiscovery = require('C:/Program Files/nodejs/node_modules/npm/node_modules/node-service-discovery/lib/ServiceDiscovery');


//Create a Ranger Client
var rangerClient = Ranger.newClient(process.env.ZK_CONNECTION_STRING || 'localhost:9001');

/** start emits 'connected' event. You can initialize following things after the event
 *  Eg: rangerClient.once('connected') { //initialize following code }
 */
rangerClient.start();

var healthCheck = function () {
        var isHealthy = true;
        return {
            isHealthy: function () {
                return isHealthy;
            },
            setStatus: function (status) {
                isHealthy = status;
            }
        }
};

/**
 * Register a Service
 *
 * process.env.environment is whatever is the environment you are using
 * Additionally, you can also bind the health-checks with the service instance (healthcheck is optional)
 */

var serviceInstance = ServiceInstanceBuilder
        .builder()
        .host("localhost")
        .port(9100) //integer
        .environment(process.env.environment || 'development')
        .healthChecks([healthCheck])
        .name('my-service')
        .build();

var serviceDiscovery = new ServiceDiscovery(rangerClient, 'services', serviceInstance, 5000);

serviceDiscovery.registerService(function(error) {
    //check for error
    console.log('Error in ServiceRegistration.');
    console.log(error);
});

module.exports.serviceInstance = serviceInstance;

Please help me regarding how to use this module for service registration. or suggest any alternate module for my scenario with good support available in internet.

Thanks.

via user2324149