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<div align="center"> <a href="http://pm2.keymetrics.io"> <img width=411px src="https://raw.githubusercontent.com/keymetrics/pmx/master/pres/logo.png"> </a> <br/> <b><a href="https://github.com/Unitech/pm2">PM2</a> programmatic integration</b> <br/> <br/> <a href="https://travis-ci.org/keymetrics/pmx"> <img src="https://api.travis-ci.org/keymetrics/pmx.png?branch=master"/> </a> <br/> <br/> </div>

PMX allows you to create advanced interactions with PM2 and Keymetrics.io.

Table of Contents

Installation

Install pmx with npm:

$ npm install pmx --save

Expose Metrics: Measure anything

PMX allows you to expose code metrics from your code to the PM2 monit command or the Keymetrics Dashboard, in realtime and over time.

4 measurements are available:

Metric: Simple value reporting

This allow to expose values that can be read instantly.

var probe = pmx.probe();

// Here the value function will be called each second to get the value
// returned by Object.keys(users).length
var metric = probe.metric({
  name    : 'Realtime user',
  value   : function() {
    return Object.keys(users).length;
  }
});

// Here we are going to call valvar.set() to set the new value
var metric_2 = probe.metric({
  name    : 'Realtime Value'
});

metric_2.set(23);

Options

Counter: Sequential value change

Things that increment or decrement.

var probe = pmx.probe();

// The counter will start at 0
var counter = probe.counter({
  name : 'Current req processed'
});

http.createServer(function(req, res) {
  // Increment the counter, counter will eq 1
  counter.inc();
  req.on('end', function() {
    // Decrement the counter, counter will eq 0
    counter.dec();
  });
});

Options

Meter: Average calculated values

Things that are measured as events / interval.

var probe = pmx.probe();

var meter = probe.meter({
  name      : 'req/sec',
  samples   : 1  // This is per second. To get per min set this value to 60
});

http.createServer(function(req, res) {
  meter.mark();
  res.end({success:true});
});

Options

Histogram

Keeps a resevoir of statistically relevant values biased towards the last 5 minutes to explore their distribution.

var probe = pmx.probe();

var histogram = probe.histogram({
  name        : 'latency',
  measurement : 'mean'
});

var latency = 0;

setInterval(function() {
  latency = Math.round(Math.random() * 100);
  histogram.update(latency);
}, 100);

Options

Expose Functions: Trigger Functions remotely

Remotely trigger functions from Keymetrics. These metrics takes place in the main Keymetrics Dashboard page under the Custom Action section.

Simple actions

Simple action allows to trigger a function from Keymetrics. The function takes a function as a parameter (reply here) and need to be called once the job is finished.

Example:

var pmx = require('pmx');

pmx.action('db:clean', function(reply) {
  clean.db(function() {
    /**
     * reply() must be called at the end of the action
     */
     reply({success : true});
  });
});

Scoped actions (beta)

Scoped Actions are advanced remote actions that can be also triggered from Keymetrics.

Two arguments are passed to the function, data (optional data sent from Keymetrics) and res that allows to emit log data and to end the scoped action.

Example:

pmx.scopedAction('long running lsof', function(data, res) {
  var child = spawn('lsof', []);

  child.stdout.on('data', function(chunk) {
    chunk.toString().split('\n').forEach(function(line) {
      res.send(line); // This send log to Keymetrics to be saved (for tracking)
    });
  });

  child.stdout.on('end', function(chunk) {
    res.end('end'); // This end the scoped action
  });

  child.on('error', function(e) {
    res.error(e);  // This report an error to Keymetrics
  });

});

Alert System for Custom Metrics

(Specific to Keymetrics)

This alert system can monitor a Probe value and launch an exception when hitting a particular value.

Example for a cpu_usage variable:

var metric = probe.metric({
  name  : 'CPU usage',
  value : function() {
    return cpu_usage;
  },
  alert : {
    mode  : 'threshold',
    value : 95,
    msg   : 'Detected over 95% CPU usage', // optional
    func  : function() { //optional
      console.error('Detected over 95% CPU usage');
    },
    cmp   : "<" // optional
  }
});

Options

Report Alerts: Errors / Uncaught Exceptions

(Specific to Keymetrics)

By default once PM2 is linked to Keymetrics, you will be alerted of any uncaught exception. These errors are accessible in the Issue tab of Keymetrics.

Custom alert notification

If you need to alert about any critical errors you can do it programmatically:

var pmx = require('pmx');

pmx.notify({ success : false });

pmx.notify('This is an error');

pmx.notify(new Error('This is an error'));

Add Verbosity to an Alert: Express Error handler

When an uncaught exception is happening you can track from which routes it has been thrown. To do that you have to attach the middleware pmx.expressErrorHandler at then end of your routes mounting:

var pmx = require('pmx');

// All my routes
app.get('/' ...);
app.post(...);
// All my routes

// Here I attach the middleware to get more verbosity on exception thrown
app.use(pmx.expressErrorHandler());

Emit Events

Emit events and get historical and statistics. This is available in the Events page of Keymetrics.

var pmx = require('pmx');

pmx.emit('user:register', {
  user : 'Alex registered',
  email : 'thorustor@gmail.com'
});

Application level network traffic monitoring / Display used ports

You can monitor the network usage of a specific application by adding the option network: true when initializing PMX. If you enable the flag ports: true when you init pmx it will show which ports your app is listenting on.

These metrics will be shown in the Keymetrics Dashboard in the Custom Metrics section.

Example:

pmx.init({
  [...]
  network : true, // Allow application level network monitoring
  ports   : true  // Display ports used by the application
});

Advanced PMX configuration

var pmx = require('pmx').init({
  network       : true, // (default: false) Network monitoring at the application level
  ports         : true, // (default: false) Shows which ports your app is listening on
  // can be 'express', 'hapi', 'http', 'restify'
  excludedHooks: []
});

License

MIT

GA