From a Tumblr engineering blog post:
Tumblr is one of the largest users of MySQL on the web. At present, our data set consists of over 60 billion relational rows, adding up to 21 terabytes of unique relational data. Managing over 200 dedicated database servers can be a bit of a handful, so naturally we engineered some creative solutions to help automate our common processes.
Today, we’re happy to announce the open source release of Jetpants, Tumblr’s in-house toolchain for managing huge MySQL database topologies. Jetpants offers a command suite for easily cloning replicas,