Can nginx be used as a reverse proxy for a backend websocket server?

Question

We\'re working on a Ruby on Rails app that needs to take advantage of html5 websockets. At the moment, we have two separate \"servers\" so to speak: our main app running on

Answer 1

Out of the box (i.e. official sources) Nginx can establish only HTTP 1.0 connections to an upstream (=backend), which means no keepalive is possibe: Nginx will select an upstream server, open connection to it, proxy, cache (if you want) and close the connection. That's it.

This is the fundamental reason frameworks requiring persistent connections to the backend would not work through Nginx (no HTTP/1.1 = no keepalive and no websockets I guess). Despite having this disadvantage there is an evident benefit: Nginx can choose out of several upstreams (load balance) and failover to alive one in case some of them failed.

Edit: Nginx supports HTTP 1.1 to backends & keepalive since version 1.1.4. "fastcgi" and "proxy" upstreams are supported. Here it is the docs