make following changes to /etc/nginx/nginx.conf in http { section
proxy_connect_timeout 600s;
proxy_send_timeout 600s;
proxy_read_timeout 600s;
fastcgi_send_timeout 600s;
fastcgi_read_timeout 600s;
proxy_connect_timeout 600s;
proxy_send_timeout 600s;
proxy_read_timeout 600s;
fastcgi_send_timeout 600s;
fastcgi_read_timeout 600s;