README
node-usage
process usage lookup with nodejs
- Simple interface to lookup cpu and memory usage of any accessible process on the system.
- Works on OSX, Linux, SmartOS and Solaris
- Tested on Heroku and Nodejitsu
Example
Code
var usage = require('usage');
var pid = process.pid // you can use any valid PID instead
usage.lookup(pid, function(err, result) {
});
Result Object
{
cpu: 10.6, //in percentage
memory: 100065280 //in no of bytes
}
Average CPU usage vs Current CPU usage
This is only applicable for Linux
By default CPU Percentage provided is an average from the starting time of the process. It does not correctly reflect the current CPU usage. (this is also a problem with linux ps
utility)
But If you call usage.lookup()
continuously for a given pid, you can turn on keepHistory flag and you'll get the CPU usage since last time you track the usage. This reflects the current CPU usage.
see following example to enable keepHistory flag
var pid = process.pid;
var options = { keepHistory: true }
usage.lookup(pid, options, function(err, result) {
});
you can clear history cache too
usage.clearHistory(pid); //clear history for the given pid
usage.clearHistory(); //clean history for all pids
Motivation
- Some of the NodeJS PAAS providers do not expose an interface to monitor CPU and Memory usage.
- They asks us to go for somewhere else for that which I don't want to go (or simply I cannot go)
- So
node-usage
was born to tackle on this.