NginX issues HTTP 499 error after 60 seconds despite config. (PHP and AWS)

The cause of the problem is the Elastic Load Balancers on AWS. They, by default, timeout after 60 seconds of inactivity which is what was causing the problem.

So it wasn't NginX, PHP-FPM or PHP but the load balancer.

To fix this, simply go into the ELB "Description" tab, scroll to the bottom, and click the "(Edit)" link beside the value that says "Idle Timeout: 60 seconds"

Actually I faced the same issue on one server and I figured out that after nginx configuration changes I didn't restart the nginx server, so with every hit of nginx url I was getting a 499 http response. After nginx restart it started working properly with http 200 responses.

I thought I would leave my two cents. First the problem is not related with php(still could be a php related, php always surprises me :P ). Thats for sure. its mainly caused of a server proxied to itself, more specifically hostname/aliases names issue, in your case it could be the load balancer is requesting nginx and nginx is calling back the load balancer and it keeps going that way.

I have experienced a similar issue with nginx as the load balancer and apache as the webserver/proxy