Memory Logger

memory-logger.js

(function() {
  'use strict';

  var _ = require('lodash');
  var moment = require('moment');
  var accounting = require('accounting');
  var path = require('path');
  var mkdirp = require('mkdirp');
  var heapdump = require('heapdump');
  require('colors');

  var bytes = 1048756;
  var period = 100;
  var frequency = period / 1000;
  var duration = 5;

  var startTime = moment();
  var startRss = process.memoryUsage().rss / bytes;
  var rssHistory = [ 0 ];

  var snapshotPath = '';
  var memoryThreshold = 0;

  var logMemory = _.throttle(function(rss, dRss, rssVAvg, rssAAvg, dump) {
    var now = moment();
    var dT = moment.duration(now.diff(startTime));
    var dTSeconds = dT.seconds();
    var dTMinutes = dT.minutes();

    var spacer = '     ';

    var humanizedDT = dTMinutes + ':' + (dTSeconds < 10 ? '0' + dTSeconds : dTSeconds);
    var formattedDT = spacer + 'dt: ' + humanizedDT;
    var formattedRss = spacer + 'R: ' + accounting.toFixed(rss, 3) + ' MB';
    var formattedDRss = spacer + 'dR: ' + accounting.toFixed(dRss, 3) + ' MB';
    var formattedRssVAvg = spacer + 'Vavg: ' + (rssVAvg <= 0 ? '-' : '+') + accounting.toFixed(Math.abs(rssVAvg), 3) + ' MB/s';
    var formattedRssAAvg = spacer + 'Aavg: ' + (rssAAvg <= 0 ? '-' : '+') + accounting.toFixed(Math.abs(rssAAvg), 3) + ' MB/s^2';

    var logList = [ now.valueOf().toString().grey.italic ];
    logList.push(formattedDT.grey);
    logList.push(formattedRss);
    logList.push(formattedDRss.yellow);
    logList.push(rssVAvg < 0 ? formattedRssVAvg.green : (rssVAvg > 0 ? formattedRssVAvg.red : formattedRssVAvg.grey));
    logList.push(rssAAvg < 0 ? formattedRssAAvg.green : (rssAAvg > 0 ? formattedRssAAvg.red : formattedRssAAvg.grey));

    console.log.apply(console, logList);

    if (!dump || dRss < memoryThreshold) {
      return;
    }

    console.log('Snapshot');
    heapdump.writeSnapshot(path.join(snapshotPath, humanizedDT + ' - ' + memoryThreshold + 'MB.heapsnapshot'));
    memoryThreshold += 10;
  }, 1000);

  function getMemoryStats(dump) {
    var memory = process.memoryUsage();

    var rss = memory.rss / bytes;
    var dRss = rss - startRss;

    rssHistory.push(rss);
    rssHistory = _.takeRight(rssHistory, Math.round(duration * 1000 / period));

    var rssVAvg = (rssHistory[rssHistory.length - 1] - rssHistory[0]) / (rssHistory.length * frequency);

    var midpoint = Math.round(rssHistory.length / 2);
    var v1 = (rssHistory[midpoint] - rssHistory[0]) / (midpoint * frequency);
    var v2 = (rssHistory[rssHistory.length - 1] - rssHistory[midpoint]) / (midpoint * frequency);
    var rssAAvg = (v2 - v1) / (midpoint * frequency);

    logMemory(rss, dRss, rssVAvg, rssAAvg, dump);
  }

  function start(dump, dirname) {
    if (dump) {
      snapshotPath = path.join(dirname, 'heapdump', startTime.format('YYYY-MM-DD HH:mm:ss'));
      mkdirp.sync(snapshotPath);
    }

    getMemoryStats(dump);
    return setInterval(_.partial(getMemoryStats, dump), period);
  }

  module.exports = {
    startTime: startTime,
    startRss: startRss,
    rssHistory: rssHistory,
    logMemory: logMemory,
    getMemoryStats: getMemoryStats,
    start: start
  };
})();

package.json

{
  "name": "memory-logger",
  "version": "0.1.0",
  "description": "Logs out RSS memory usage, velocity, and acceleration.",
  "main": "memory-logger.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "author": "Alexander Martin",
  "license": "MIT",
  "dependencies": {
    "accounting": "^0.4.1",
    "colors": "^1.0.3",
    "heapdump": "^0.3.5",
    "lodash": "^3.7.0",
    "mkdirp": "^0.5.0",
    "moment": "^2.10.2"
  }
}