writes "Facebook's engineers face a considerable challenge when it comes to managing the tidal wave of data flowing through the company's infrastructure. Its data warehouse, which handles over half a petabyte of information each day, has expanded some 2500x in the past four years — and that growth isn't going to end anytime soon. Until early 2011, those engineers relied on a MapReduce implementation from Apache Hadoop as the foundation of Facebook's data infrastructure. Still, despite Hadoop MapReduce's ability to handle large datasets, Facebook's scheduling framework (in which a large number of task trackers that handle duties assigned by a job tracker) began to reach its limits. So Facebook's engineers went to the whiteboard and designed a new scheduling framework named Corona."
Facebook is continuing development on Corona, but they've also open-sourced the version they currently use