Facebook uses ‘anime’ BitTorrent tracker code to update its network
Mon 16 Feb 2015

Facebook is using a BitTorrent tracker originally designed for the sharing of anime characters in order to deploy updates to its tremendously busy servers, TorrentFreak notes today. Talking to the developers of Chihaya, the site reports that the tool, named after a schoolgirl anime character from a manga series called Chihayafuru, is used by the $190bn company to distribute server updates.
The project developed out of the need to find a better tracker solution than 2008’s Gazelle, which itself replaced the Ocelot tracker. The subsequent development was Batter, at which point the Chihaya development community joined nascent programmers such as Justin Li in the endeavour.
Li and fellow developer Jimmy Zelinskie kept progress on the Chihaya project alive even as the Batter initiative came to a halt. Speaking to TF, Zelinskie said “We restructured Chihaya a few times, trying to decide how to make it scalable and ultimately landed on what we have today.”
The Go-based Chihaya project was started as a new tracker solution by developer Kotoko in 2012, with the sole aim of serving the Torrent-based fan community for the manga series.
“I was interested in helping out with Chihaya back then,” says Zelinskie, “because I wanted to work on a project to cement my skills in the Go programming language.”
In 2010 Tom Cook of Facebook’s system engineering group revealed the extent to which the social networking behemoth leverages BitTorrent, at the Velocity conference. “BitTorrent is fantastic for this,” said Cook at the time. “It’s ‘superduper’ fast and it allows us to alleviate a lot of scaling concerns we’ve had in the past, where it took forever to get code to the webservers before you could even boot it up and run it.”
Twitter also uses BitTorrent to update its demanding and high-volume network, with a framework called Murder.