Error with passenger: Returning HTTP 503 due to: Request queue full

[urielhdz]

My site goes down as soon as I mount the Faye middleware on Passenger 5.06 and nginx 1.6.2.

This is how I'm mounting the middleware:

config.middleware.delete Rack::Lock
    if Rails.env.production?
        config.middleware.use FayeRails::Middleware, mount: '/faye', :timeout => 25, server: 'passenger',                
             engine: {type: Faye::Redis, host: 'localhost'}
    else
        config.middleware.use FayeRails::Middleware, mount: '/faye', :timeout => 25 
    end

In my local machine with Thin everything works as expected.

I have faye-redis on my Gemfile and redis server 3.0.5 installed on my server.

I was wondering if is there extra configuration that has to be done on Nginx to support websockets or if it works out the box.

My nginx log files show the following:

Connection reset by peer) while sending to client, client: x.x.x.x, server: domain.com, request: "POST /faye HTTP/1.1, upstream: "passenger:unix:/tmp/passenger.3zszl5P/agents.s/server:"

And eventually

Returning HTTP 503 due to: Request queue full (configured max. size: 100)