appmetrics-dash provides a very easy to use, web based, dashboard to show the performance metrics of your running Node.js application.

The data available on the dashboard is as follows:

• HTTP Incoming Requests
• HTTP Throughput
• Average Reponse Times (top 5)
• CPU
• Memory
• Heap
• Event loop Latency
• Environment
• Other Requests
• HTTP Outbound Requests

As well as displaying data, it also provides the ability to generate both Node Report and Heap Snapshots directly from the dashboard. The Node Report will display in a new tab in the browser whilst the Heap Snapshot will be written to disk for loading into the Chrome DevTools for analysis.

The dashboard uses Node Application Metrics to monitor the application.

npm install appmetrics-dash

Our testing has shown that the performance overhead in terms of processing is minimal, adding less than 0.5 % to the CPU usage of your application. The additional memory required is around 30 MB to gather information about your system and application which is then visualized in the dashboard.

We gathered this information by monitoring the sample application Acme Air. We used MongoDB as our datastore and used JMeter to drive load though the program. We have performed this testing with Node.js version 6.10.3

This will launch the dashboard and start monitoring your application. When no options are specified, an http server will be created and listen on port 3001. The dashboard will be available at /appmetrics-dash

Simple example using the express framework

// This application uses express as its web server
// for more info, see: http://expressjs.com
var express = require('express');

var dash = require('appmetrics-dash').monitor();

// cfenv provides access to your Cloud Foundry environment
// for more info, see: https://www.npmjs.com/package/cfenv
var cfenv = require('cfenv');

// create a new express server
var app = express();

// serve the files out of ./public as our main files
app.use(express.static(__dirname + '/public'));

// get the app environment from Cloud Foundry
var appEnv = cfenv.getAppEnv();

// start server on the specified port and binding host
var server = app.listen(appEnv.port, '0.0.0.0', function() {
	// print a message when the server starts listening
  console.log("server starting on " + appEnv.url);
});

• options.url {String} Path to serve dashboard from. Optional, defaults to '/appmetrics-dash'.
• options.console {Object} Some messages are printed to the console using console.log() and console.error(). Optional, defaults to the global console object.
• options.server {Object} An instance of a node http server to serve the dashboard from. Optional, default is to create a server (see port and host).
• options.port {String|Number} Port to listen on if creating a server. Optional, unused if server option is used.
• options.host {String} Host to listen on if creating a server. Optional, unused if server option is used.
• options.appmetrics {Object} An instance of require('appmetrics') can be injected if the application wants to use appmetrics, since it is a singleton module and only one can be present in an application. Optional, defaults to the appmetrics dependency of this module.
• options.node-report {Object} An instance of require('node-report') can be injected if the application wants to use node-report, since it is a singleton module and only one can be present in an application. Optional, defaults to the node-report dependency of this module.
• options.title {String} Title for the dashboard.
• options.docs {String} URL link to accompanying documentation.

• options {Object} Options are the same as for dash.monitor().

Auto-attach to all http servers created after this call, calling dash.monitor(options) for every server.

Simple example using attach

var dash = require('appmetrics-dash');
dash.attach();

var http = require('http');

const port = 3000;

const requestHandler = (request, response) => {  
  response.end('Hello')
}

const server = http.createServer(requestHandler);

server.listen(port, (err) => {  
  if (err) {
    return console.log('An error occurred', err)
  }
  console.log(`Server is listening on ${port}`)
});

We welcome contributions. Please see CONTRIBUTING.md for details about the contributor licence agreement and other information. If you want to do anything more involved than a bug fix or a minor enhancement then we would recommend discussing it in an issue first before doing the work to make sure that it's likely to be accepted. We're also keen to improve test coverage and may not accept new code unless there are accompanying tests.

The Node Application Metrics Dashboard is licensed using an Apache v2.0 License.