proxy_next_upstream off;
proxy_redirect      off;
proxy_connect_timeout 300s;
proxy_read_timeout 600s;
proxy_send_timeout 600s;
proxy_buffer_size 32k;
proxy_buffers 4 32k;
proxy_busy_buffers_size 64k;
proxy_hide_header Vary;

proxy_http_version 1.1;

proxy_set_header   Accept-Encoding '';
proxy_set_header   Host $host;
proxy_set_header   Referer $http_referer;
proxy_set_header   Cookie $http_cookie;
proxy_set_header   X-Real-IP  $remote_addr;
proxy_set_header   X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header   X-Forwarded-Proto $scheme;
proxy_set_header   Upgrade $http_upgrade;
proxy_set_header   Connection $connection_upgrade;