kstat
v1.1.2
Published
illumos libkstat bindings
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node-kstat
This repository is part of the Triton Data Center project. See the contribution guidelines and general documentation at the main Triton project page.
A node.js binding to the illumos kstat interface. This allows one to read kernel statistics via the kstat framework. It is likely to work unmodified on Solaris too.
Usage
The kstat
module exports a single class, Reader
that has the following
methods:
Reader(): Takes an optional object specifying the kstats to read. This
object may have the following members:
class => optional string denoting class of kstat(s) to read
module => optional string denoting module of kstat(s) to read
name => optional string denoting name of kstat(s) to read
instance => optional integer denoting instance of kstat(s) to read
Together, these members form a specification of kstats to read.
read(): Returns an array of kstats that match the specification with
which the reader instance was constructed *and* an optional
specification passed to this function. Each element of the
array is an object that contains the following members:
class => string denoting class of kstat
module => string denoting module of kstat
name => string denoting name of kstat
instance => integer denoting instance of kstat
snaptime => nanoseconds since boot of this snapshot
data => an object containing the named kstat data itself
Examples
Here is a simple program that dumps the kstats of class mib2
:
var kstat = require('kstat');
var util = require('util');
var reader = new kstat.Reader({ 'class': 'mib2' } );
console.log(util.inspect(reader.read()));
Here is a the same program that reads only the mib2
class kstats from the
icmp
module:
var kstat = require('kstat');
var util = require('util');
var reader = new kstat.Reader({ 'class': 'mib2', module: 'icmp' } );
console.log(util.inspect(reader.read()));
Finally, here is a simple program that prints the number of ICMP datagrams received per second:
var kstat = require('kstat');
var reader = new kstat.Reader({ 'class': 'mib2', module: 'icmp' } );
var data = [];
var gen = 0;
setInterval(function() {
data[gen] = reader.read()[0];
gen ^= 1;
if (!(data[0] && data[1]))
return;
console.log(data[gen ^ 1].data.inDatagrams - data[gen].data.inDatagrams);
}, 1000);
You can find further example programs in the examples directory.
License
MIT.