brycebaril

var Transform = require("stream").Transform
var inherits = require("util").inherits

module.exports.ctor = function ctor(fn) {
  function T(options) {
    if (!(this instanceof T)) return new T(options)
    Transform.call(this, options)
  }
  inherits(T, Transform)
  T.prototype._transform = fn

brycebaril

var lvlup = require("levelup")

var db = lvlup("/tmp/source_db")

var batch = 10000

function makeBatch(num) {
  var b = []
  for (var i = num; i < num + batch; i++) {
    b.push({type: "put", key: "z~" + i, value: Math.random()})

brycebaril

        fs.readFile('/proc/meminfo', 'utf8', function (err, str) {
            var fields = {};
            str.split('\n').forEach(function (line) {
                var parts = line.split(':');
                if (parts.length === 2) {
                    fields[parts[0]] = parts[1].trim().split(' ', 1)[0];
                }
            });
            cb(fields['MemTotal'] + fields['Buffers'] + fields['Cached']);

brycebaril

> var redis = require("redis")
undefined
> var c = redis.createClient()
undefined
> c.blpop("Dispo", 0, console.log)
true
> null [ 'Dispo', 'foo' ]

brycebaril

var cluster = require('cluster');
var PORT = +process.env.PORT || 1337;

if (cluster.isMaster) {
  // In real life, you'd probably use more than just 2 workers,
  // and perhaps not put the master and worker in the same file.
  cluster.fork();
  cluster.fork();

  cluster.on('disconnect', function(worker) {

brycebaril

// Short module explanation             // Something to gather my thoughts
//                                      // I think this looks cool.
                                        //
module.exports = the_exported_function  // Modules are a function. Always.
                                        //
module.exports.extra = extra            // Additional API entry points if
module.exports.other = other            // desired.
                                        //
var util = require('util')              // Other packages from npm or core
var assert = require('assert')          // No comma-first due to lots of

brycebaril

#!/bin/bash

if [[ $1 != "-f" ]]; then
    echo "### Dry-run mode, specify -f to actually perform deletes.";
fi;
for branch in $(git branch -r --merged origin/master | grep '\<origin/' | grep -v '\<origin/master\>');
do
    if [[ -z $(git rev-list $branch --since '1 month') ]]; then
        name=$(echo $branch | sed 's/^origin\///');
        if [[ $1 = "-f" ]]; then

brycebaril

var async = require('async');

function one(cb) {
    console.log("running one");
    cb(null, function () { return "one" });
}

function two(cb) {
    console.log("running two");
    function three(callback){

brycebaril

Trying N|Solid

1. Download the N|Solid Runtime https://downloads.nodesource.com/
2. tar -xf nsolid-v1.0...
3. cd nsolid-v1.0...
4. ./nsolid /path/to/your/app.js

Now let's get tricky

1. NSOLID_SOCKET=8000 ./nsolid /path/to/your/app.js

brycebaril

Y axis = stack depth X axis = percent of time spent in this function

If a function sits atop another, it was in its callchain and spent time in the callee. The more of a parent that is covered by the things it calls, the less it is doing and the more its children are doing.

This means the two main things (in my experience) to look for are:

• plateaus -- functions where a lot of time was spent
• shallow-sloped pyramids -- functions where time was spent up and down the callchain vs any isolated place

In the middle of the wide section you can see a function called "parseGif" which is where we'll focus. This particular flame graph was generated to analyze something inside there -- for the most part I don't care about the rest right now.