By default, NGINX only allows body's of 1M. Currently, there is a setting in the .rtorrent.rc file for XMLRPC size limit, which is only effective below 1M because above 1M, NGINX steps in and disallows the request with error 413 Request Entity Too Large.
By default, NGINX only allows body's of 1M. Currently, there is a setting in the .rtorrent.rc file for XMLRPC size limit, which is only effective below 1M because above 1M, NGINX steps in and disallows the request with error 413 Request Entity Too Large.