When Facebook's VP of Technology, Jeff Rothschild, delivered a lecture at Calit2 Oct. 8 at the invitation of the Center for Networked Systems (CNS), he divulged some key statistics that made news in high-tech publications that follow the data center industry. Rothschild's talk was webcast live by Calit2 and the archived version of "High Performance at Massive Scale" is now available for on-demand viewing [Windows Media player and broadband connection required]. As the blog High Scalability reports, Rothschild divulged that "Facebook handles 30K+ machines, 300 million active users, 20 billion photos, and 25TB per day of logging data."

Then in the Oct. 13 issue of Data Center Knowledge, Rich Miller notes that until now, since April 2008, Facebook's stock answer about how many servers it uses was "more than 10,000 servers." In his talk, Rothschild said "today we have somewhere in the neighborhood of 30,000 servers," which means that Facebook has added roughly 20,000 servers in just the past 18 months. Data Center Knowledge also took note of other Facebook statistics revealed by Rothschild in his talk at Calit2: Facebook serves up 600,000 photos every second, and the 25TB of data per day in logging data is the equivalent of about 1,000 times the volume of mail delivered daily by the U.S. Postal Service.