During a keynote session at the OSCON open source conference, David Recordon, the senior open programs manager at Facebook, detailed the infrastructure in use today at Facebook.
At the language level of the stack, Recordan noted that Facebook is using PHP by way of its own HipHop PHP runtime project. Facebook officially announced HipHop earlier this year as a way to speed up PHP operations, improve efficiency and decrease CPU utilization.
At the database tier, Recordan said Facebook primarily stores user data in the MySQL database. He said that Facebook runs thousands of MySQL nodes, though he added that Facebook doesn't care that MySQL is a relational database.
Recordan said that Facebook has three different layers for data. At the first layer is the database tier, which is the primary data store and where MySQL sits. On top of that, Facebook uses Memcached caching technology, then a Web server on top of that to serve the data.
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