Rafael Jesus rafaeljesus

If you haven't read Netflix's Node.js in Flames blog post you should. It is a great deep dive into debugging a node performance problem. The post includes useful tips that can help you solve similar problems.

That said...

My feedback from the perspective of a framework developer is quite different. I found the tone and attitude towards express.js to be concerning and somewhat offensive. Here was a developer blaming the framework he chose for poor architecture when they never bothered to actually learn how the framework works in the first place. Everything that followed originated from this basic lack of understanding.

Express uses a very simple router logic which is at the core of how express works, so let’s examine that first (my knowledge of express is somewhat dated but I think the principle is still the same). Express keeps a hash of the various HTTP methods (GET, POST, etc.) and for each method, an array of middlewares. Each middleware is ju

Essential JavaScript Links

A curated list by Eric Elliott and friends. Suggest links in the comments below.

This is a very exclusive collection of only must-have JavaScript links. I'm only listing my favorite links. Nothing else makes the cut. Feel free to suggest links if you think they're good enough to make this list. The really curious should feel free to browse the comments to find other links. I can't guarantee the quality of links in the comments.

Full Disclosure

Some of these links are affiliate links, meaning that if you make a purchase, I might earn a little money. This has absolutely no bearing on whether or not links make the list. None, whatsoever. However, it does allow me more resources to fight poverty with code. Every little bit counts.

HAProxy + Consul vs VulcanD + EtcD

HAProxy/Consul

Pro: Both are production ready
Pro: Can handle any throughput we will see
Pro: More feature rich
1. Healthchecks
2. DNS and HTTP API available to map endpoints
3. Lots of service discovery built in
Pro: Solution could be used in more than one place (bld/prod/etc..)

Abstraction Suggestions

Summary: use good/established messaging patterns like Enterprise Integration Patterns. Don't make up your own. Don't expose transport implementation details to your application.

Broker

As much as possible, I prefer to hide Rabbit's implementation details from my application. In .Net we have a Broker abstraction that can communicate through a lot of different transports (rabbit just happens to be our preferred one). The broker allows us to expose a very simple API which is basically:

publish
request
start/stop subscription

Parse AWS IP ranges

Write a simple script to take the AWS IP ranges from https://ip-ranges.amazonaws.com/ip-ranges.json and output the range and location for each range in CSV format, e.g.:

23.20.0.0/14,"CA, US"
27.0.0.0/22,"Tokyo, JP"
...

Overview

We run multiple server processes in two data centers. Each process listens on two ports, one for HTTP and one for HTTPS. HTTPS is terminated by Apache prior to reaching node.js. HTTP goes directly from the client to node.js (through a master load balancer). We do not use clusters. We slice our physical servers into thin virtual machines running SmartOS, each with about 3GB of memory designed for a single node.js process.

Our node.js servers are hapi.js servers using the composer functionality and plugins architecture. We have three sets of plugins loaded: mobile web front end experience (single page app), legacy API reverse proxy, and monitoring.

We also serve original node.js services off another server zone which runs closed source plugins using hapi.

	callLog = [];

	/* set up an override for the Function call prototype
	* @param func the new function wrapper
	*/
	function registerOverride(func) {
	oldCall = Function.prototype.call;
	Function.prototype.call = func;
	}

	// TL;DR - Lambda means "function used as data".
	// Anonymous function means "function without a name".

	// This is one of the relatively few cases where the Wikipedia definition of
	// a word, while not entirely wrong, is misleading. Lambdas and anonymous
	// functions are distinct ideas.

	// These ideas are commonly confused because in many programming languages
	// all lambdas are anonymous or vise verse.

	// Promise.all is good for executing many promises at once
	Promise.all([
	promise1,
	promise2
	]);

	// Promise.resolve is good for wrapping synchronous code
	Promise.resolve().then(function () {
	if (somethingIsNotRight()) {
	throw new Error("I will be rejected asynchronously!");

	// This script will boot app.js with the number of workers
	// specified in WORKER_COUNT.
	//
	// The master will respond to SIGHUP, which will trigger
	// restarting all the workers and reloading the app.

	var cluster = require('cluster');
	var workerCount = process.env.WORKER_COUNT \|\| 2;

	// Defines what each worker needs to run