Using Node.js only vs. using Node.js with Apache/Nginx

Question

There are several good reasons to stick another webserver in front of Node.js:

• Not having to worry about privileges/setuid for the Node.js process. Only root can bind to port 80 typically. If you let nginx/Apache worry about starting as root, binding to port 80, and then relinquishing its root privileges, it means your Node app doesn't have to worry about it.
• Serving static files like images, css, js, and html. Node may be less efficient compared to using a proper static file web server (Node may also be faster in select scenarios, but this is unlikely to be the norm). On top of files serving more efficiently, you won't have to worry about handling eTags or cache control headers the way you would if you were servings things out of Node. Some frameworks may handle this for you, but you would want to be sure. Regardless, still probably slower.
• As Matt Sergeant mentioned in his answer, you can more easily display meaningful error pages or fall back onto a static site if your node service crashes. Otherwise users may just get a timed out connection.
• Running another web server in front of Node may help to mitigate security flaws and DoS attacks against Node. For a real-world example, CVE-2013-4450 is prevented by running something like Nginx in front of Node.

I'll caveat the second bullet point by saying you should probably be serving your static files via a CDN, or from behind a caching server like Varnish. If you're doing this it doesn't really matter if the origin is Node or Nginx or Apache.

Caveat with nginx specifically: if you're using websockets, make sure to use a recent version of nginx (>= 1.3.13), since it only just added support for upgrading a connection to use websockets.

Just to add one more reason to pauljz's answer, I use a front end server so that it can serve up 502 error pages when I'm restarting the backend server or it crashes for some reason. This allows your users to never get an error about unable to establish a connection.

It is my belief that using Node to serve static files is fine in all circumstances as long as you know what you're doing. It is certainly a new paradigm to use the application server to serve static files as so many (every?) competing technologies (PHP, Ruby, Python, etc) require a web server like HTTPD or Nginx in front of the application server(s).

Every objective reason I have ever read against serving static files with Node revolves around the idea of using what you know best or using what is perceived as better-tested / more stable. These are very valid reasons practically speaking, but have little purely technical relevance.

Unless you find a feature that is possible with a classic web server that is not possible with Node (and I doubt you will), choose what you know best or what you'd prefer to work with as either approach is fine.

As for Nginx vs Apache -- they will "play" with Node the same. You should compare them without regard to Node.

Placing NGINX in front of Node helps better handle high connection volumes. NGINX offers (to name a few) caching, load balancing, rate limiting (using the leaky bucket algorithm) and can help mitigate attacks if paired with a banning service like Fail2ban.

As for production applications, you can run your application server behind NGINX as reverse proxy, coupled with a caching server like Redis- all of which can be situated behind a content delivery network as another line of defense from exposing your ipv4/ipv6.

An extra: It is important also if you need a Reverse Proxy, for example to execute a Websocket Server on the same port, or maybe mix some techonlogies (reply with NodeJS some requests and with PHP some others or whatever)

Using Node.js only

Node.js can do all the tasks of a web server: serve static files, respond to an API call, run server on HTTPS... There are also a lot of packages that provide extra functionalities like logging the request, compress the response, set cookies, prevent XSS attacks... Lack of functionalities isn't likely a reason for using another Webserver (Apache/Nginx/etc..) to complete Node.js. In other words, for a simple application that does not need to scale, you don't need to add an extra layer to Node.js, it just complicates the problem.

Using Node.js with another webserver

Each web server has its own advantages. For example, Apache allows additional configuration per-directory via the .htaccess file. Nginx is known for its performance when it comes to serving static files or acting as an reverse proxy. Node.js provides a huge benefit when dealing with I/O heavy systems... Sometimes, we need to combine the forces of different web servers to satisfy the system's requirements.

Example: For an enterprise-level application that might scale up in the future, set up Nginx as a reverse proxy before Node.js application has some advantages :

• Nginx can act as a load balancer to dispatch traffic to your NodeJS instances if you have more than 1.
• Nginx can handle HTTPS, caching, and compression for you. Encryption and compression are heavily computed operations that NodeJS is not good at. So using Nginx will give you better performance.
• Nginx will serve static content, which reduces the load of Node.js.
• Separation of concerns: Nginx takes care of all the "configuration" part, and Node.js focus on the application logic.