Delegate anything possible (e.g. static content, gzip) to a reverse proxy

One Paragraph Explainer

It’s very tempting to cargo-cult Express and use its rich middleware offering for networking related tasks like serving static files, gzip encoding, throttling requests, SSL termination, etc. This is a performance kill due to its single threaded model which will keep the CPU busy for long periods (Remember, Node’s execution model is optimized for short tasks or async IO related tasks). A better approach is to use a tool that expertise in networking tasks – the most popular are nginx and HAproxy which are also used by the biggest cloud vendors to lighten the incoming load on node.js processes.

Nginx Config Example – Using nginx to compress server responses

  1. # configure gzip compression
  2. gzip on;
  3. gzip_comp_level 6;
  4. gzip_vary on;
  6. # configure upstream
  7. upstream myApplication {
  8.     server 127.0.0.1:3000;
  9.     server 127.0.0.1:3001;
  10.     keepalive 64;
  11. }
  13. #defining web server
  14. server {
  15.     # configure server with ssl and error pages
  16.     listen 80;
  17.     listen 443 ssl;
  18.     ssl_certificate /some/location/sillyfacesociety.com.bundle.crt;
  19.     error_page 502 /errors/502.html;
  21.     # handling static content
  22.     location ~ ^/(images/|img/|javascript/|js/|css/|stylesheets/|flash/|media/|static/|robots.txt|humans.txt|favicon.ico) {
  23.     root /usr/local/silly_face_society/node/public;
  24.     access_log off;
  25.     expires max;
  26. }

What Other Bloggers Say

…It’s very easy to fall into this trap – You see a package like Express and think “Awesome! Let’s get started” – you code away and you’ve got an application that does what you want. This is excellent and, to be honest, you’ve won a lot of the battle. However, you will lose the war if you upload your app to a server and have it listen on your HTTP port because you’ve forgotten a very crucial thing: Node is not a web server. As soon as any volume of traffic starts to hit your application, you’ll notice that things start to go wrong: connections are dropped, assets stop being served or, at the very worst, your server crashes. What you’re doing is attempting to have Node deal with all of the complicated things that a proven web server does really well. Why reinvent the wheel? This is just for one request, for one image and bearing in mind this is the memory that your application could be used for important stuff like reading a database or handling complicated logic; why would you cripple your application for the sake of convenience?

Although express.js has built-in static file handling through some connect middleware, you should never use it. Nginx can do a much better job of handling static files and can prevent requests for non-dynamic content from clogging our node processes…