I am running into an issue, that I believe was documented here (https://trac.nginx.org/nginx/ticket/1005).

Essentially, I am seeing alerts as our ELBs are sending 504s back to clients with no backend information attached, but when I look through our nginx request logs, I see that we "should have" sent them a 408. However, it appears that nginx is just closing the connection.

We are using keep-alive connections, and I was looking at using the reset_timedout_connection parameter, but based on the documentation it doesn't seem like this will help.

Is there a way to actually send a 408 back to the client using nginx and ELBs?