Before we get into the details, here are a few factoids to give you an idea of the scaling challenge that Facebook has to deal with:
- Facebook serves 570 billion page views per month (according to Google Ad Planner).
- There are more photos on Facebook than all other photo sites combined (including sites like Flickr).
- More than 3 billion photos are uploaded every month.
- Facebook’s systems serve 1.2 million photos per second. This doesn’t include the images served by Facebook’s CDN.
- More than 25 billion pieces of content (status updates, comments, etc) are shared every month.
- Facebook has more than 30,000 servers (and this number is from last year!)