Way back in 2014 I've written about a few collectd configurations. One of them was using various tools to manage rtorrent to gather information from rtorrent.
As one reader of this blog asked me about the scripts I wanted to release a simpler approach to gather the information from rtorrent.
This one is based on the curl_xml Plugin. Therefore much of the overhead is being avoided and shorter intervals are possible.
Just change the url of the below config file to the path to your rtorrents RPC2 and make sure the collectd client can reach it without password protection.