Why does Unicorn need to be deployed together with Nginx?

ruby-on-rails nginx webserver unicorn
loganathan picture loganathan · Jan 5, 2012 · Viewed 33.3k times · Source

I would like to know the difference between Nginx and Unicorn. As far as I understand, Nginx is a web server while Unicorn is a Ruby HTTP server.

Since both Nginx and Unicorn can handle HTTP requests, what is the need to use the combination of Nginx and Unicorn for RoR applications?

Answer

Nick picture Nick · Jan 6, 2012

Nginx is a pure web server that's intended for serving up static content and/or redirecting the request to another socket to handle the request.

Unicorn is a Rack web server and only intended to host a 'Rack App' which is usually generating dynamic content. Rack apps can also serve up static content but it's less efficient than most other traditional web servers.

Most RoR setups use a combination of both traditional web servers and Rack servers to apply the best of both of their capabilities. Nginx is incredibly fast at request redirection through proxy balancing and serving up static content. Unicorn is quite capable of processing HTTP headers and balancing inbound requests to Ruby for processing.

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