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Streaming Performance Monitor metrics for Node on Windows.

node-perfmon is a thin wrapper around typeperf, and provides a ReadableStream interface to the typeperf output. Metrics are streamed once per second. perfmon wraps up the typeperf executable as a child_process. It ensures that no more than one process will be spawned for each host machine streaming metrics.


Node, Windows, and the typeperf executable in your path. I've never seen a Windows installation that didn't have it, but it's not out of the realm of possibility. Windows For Workgroups 3.11 had it. Maybe. Definitely NT4 and up.

Only the machine running Node needs Node. Makes perfect sense. The only requirements to stream metrics from a remote machine are Windows running on that machine, and appropriate permissions to do so.


npm install perfmon


The most basic usage is to stream a single metric from the local machine. The perfmon function returns an instance of a ReadableStream. You can either pass a callback as the last argument, or attach to the data and error events on the returned Stream.

The first two arguments to perfmon, counters and hosts, can be strings or arrays. hosts is optional and assumed to be local machine if not specified.

var perfmon = require('perfmon');
perfmon('\\processor(_total)\\% processor time', function(err, data) {

The data object logged to the console:

{ host: 'yourcomputer',
  time: 1328067580990, // UTC timestamp in ms 
  { '\\processor(_total)\\% processor time': 17 }

List available metric counters

Use list to return a, um, list of available counters.

perfmon.list('memory', function(err, data) {

The data object logged to the console:

{ counters:
  [ 'memory\\Page Faults/sec',
    'memory\\Available Bytes',
    'memory\\Committed Bytes',
    // ... omitted for brevity ... 
    'memory\\Available KBytes',
    'memory\\Available MBytes',
    'memory\\Transition Pages RePurposed/sec',
    'memory\\Free & Zero Page List Bytes',
    'memory\\Modified Page List Bytes',
    'memory\\Standby Cache Reserve Bytes',
    'memory\\Standby Cache Normal Priority Bytes',
    'memory\\Standby Cache Core Bytes' ],
host: 'yourcomputer' }

Stream remote host metrics

You can connect to any host on your network and stream metrics from that machine.

var counters = [
    '\\processor(_total)\\% processor time',
    '\\memory\\available bytes',
perfmon(counters, 'somecomputer.somewhere.local', function(err, data) {