Facebook usage of HBase and Haystack

This interesting video explains how Facebook uses Hbase for storing messages, email, etc. Hbase is a very good general purpose storage supporting fault-tolerance, replica and self balance. HBase is a public domain solution similar to google Hbase. So in a sense, Facebook is leveraging Google old ideas. Also, they are using an internal solution Haystack for storing attachments. Haystack is also used for the image product.