How do I prevent a Gateway Timeout with FastCGI on Nginx

Proxy timeouts are well, for proxies, not for FastCGI...

The directives that affect FastCGI timeouts are client_header_timeout, client_body_timeout and send_timeout.

Edit: Considering what's found on nginx wiki, the send_timeout directive is responsible for setting general timeout of response (which was bit misleading). For FastCGI there's fastcgi_read_timeout which is affecting the FastCGI process response timeout.

For those using nginx with unicorn and rails, most likely the timeout is in your unicorn.rb file

put a large timeout in unicorn.rb

timeout 500

if you're still facing issues, try having fail_timeout=0 in your upstream in nginx and see if this fixes your issue. This is for debugging purposes and might be dangerous in a production environment.

upstream foo_server {
        server 127.0.0.1:3000 fail_timeout=0;
}