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Posts Tagged ‘Facebook’

Why Social Networks Are Monopolistic By Nature?

December 12th, 2011 No comments

Social networking has been the hottest area after the dot.com burst. User base is still a critical factor and far more sticky than before. It’s the connections among these users that differentiate social networking from other types of Internet services.

A connection is formed from one user to another. They cannot be on two different web sites, even though theoretically they can. Technically we can define protocols to link users, even groups, together from different sites. But it is not efficient and may not be fast enough to sync up states and discover new connections. Even more issues on business side, not to mention privacy policies.

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Critical Lessons Learned at Facebook on Scalability and Reliability

November 21st, 2010 1 comment

Facebook.com is no doubt the biggest web site surpassing Google in terms of Web traffics in an article published half year ago. Given its scale, the lessons learned would be very helpful for others to build scalable IT infrastructures. This post is based on my notes taken at the talk by Robert Johnson and Sanjeev Kumar at LISA 2010 conference. Should there be any mistakes, they are all mine.

According to the speakers, the architecture of Facebook.com is relatively simple: Web servers in the front, databases at the back. In the middle is a caching layer with a lot of memcached servers. If you recall my previous post, they use PHP extensively.

Unlike other sites, like email sites, whose users are well mapped and isolated to different servers, social Websites like Facebook have unique challenges in that their users are linked together. Errors in one part of a system may cascade easily and bring down the whole site.

Here are several important lessons Facebook learned while building software and operating the site: