cnn-metrics/lib/plugins/system/process.js

CNN Metrics

'use strict';

const _ = require('lodash'),
    os = require('os'),
    metrics = require('metrics'),
    System = function () {
        const versionTokens = process.version.split('.');

        this.nodeVersion = {
            major: parseInt(versionTokens[0].slice(1)) || 0,
            minor: parseInt(versionTokens[1]),
            patch: parseInt(versionTokens[2])
        };

        this.counters = {
            'system.process.mem_process_rss': new metrics.Counter(),
            'system.process.mem_process_heapTotal': new metrics.Counter(),
            'system.process.mem_process_heapUsed': new metrics.Counter(),
            'system.process.load_average_1m': new metrics.Counter(),
            'system.process.next_tick': new metrics.Histogram.createUniformHistogram()
        };

        this.counts = this.counts.bind(this);

        this.instrument();
    };

System.prototype.instrument = function () {
    let self = this;

    // read memory / cpu information from process module
    setInterval(function () {
        let mem = process.memoryUsage();
        self.counters['system.process.mem_process_rss'].count = mem.rss;
        self.counters['system.process.mem_process_heapTotal'].count = mem.heapTotal;
        self.counters['system.process.mem_process_heapUsed'].count = mem.heapUsed;
        self.counters['system.process.load_average_1m'].count = _.first(os.loadavg());
    }, 1000 * 5).unref();

    // event loop timing via high-resolution real time function
    function timeTick() {
        let start = process.hrtime();

        function onTick() {
            let diff = process.hrtime(start),
                nanoSecondsDiff = (diff[0] * 1e9) + diff[1];

            self.counters['system.process.next_tick'].update(nanoSecondsDiff);
        }

        process.nextTick(onTick);
    }

    setInterval(timeTick, 1000).unref();
};

System.prototype.counts = function () {
    return {
        'system.os.cpus': os.cpus().length,
        'system.process.uptime': process.uptime(),
        'system.process.version.full': process.version,
        'system.process.version.major': this.nodeVersion.major,
        'system.process.version.minor': this.nodeVersion.minor,
        'system.process.version.patch': this.nodeVersion.patch,
        'system.process.mem_process_rss': this.counters['system.process.mem_process_rss'].count,
        'system.process.mem_process_heapTotal': this.counters['system.process.mem_process_heapTotal'].count,
        'system.process.mem_process_heapUsed': this.counters['system.process.mem_process_heapUsed'].count,
        'system.process.load_average_1m': this.counters['system.process.load_average_1m'].count,
        'system.process.next_tick.mean': this.counters['system.process.next_tick'].mean(),
        'system.process.next_tick.stdDev': this.counters['system.process.next_tick'].stdDev(),
        'system.process.next_tick.min': this.counters['system.process.next_tick'].min,
        'system.process.next_tick.max': this.counters['system.process.next_tick'].max,
        'system.process.next_tick.sum': this.counters['system.process.next_tick'].sum
    };
};

module.exports = System;