Upstream too big - nginx + codeigniter
Add this to your http {} of the nginx.conf file normally located at /etc/nginx/nginx.conf:
proxy_buffer_size 128k;proxy_buffers 4 256k;proxy_busy_buffers_size 256k;Then add this to your php location block, this will be located in your vhost file look for the block that begins with location ~ .php$ {
fastcgi_buffer_size 128k;fastcgi_buffers 4 256k;fastcgi_busy_buffers_size 256k;
Modify your nginx configuration and change/set the following directives:
proxy_buffer_size 128k; proxy_buffers 4 256k; proxy_busy_buffers_size 256k;
I have proven that this is also sent when an invalid header is transmitted. Invalid characters or formatting of the HTTP headers, cookie expiration set back by more than a month, etc will all cause: upstream sent too big header while reading response header from upstream