Amazon Web Services in Action

Part 3. Storing data in the cloud

Suppose there’s a guy named Singleton in your office who knows all about the file server. If Singleton is out of the office, no one else can maintain the file server. When Singleton goes on vacation, the file server crashes—no one knows where the backup is located, and the boss needs the document now or the company will lose a lot of money. If Singleton had stored his knowledge in a database, coworkers could look up the information. But because the knowledge and Singleton are tidily coupled, the data is unavailable.

Now imagine a server with important files located on a hard disk. As long as the server is up and running, everything is fine. But things fail all the time—and so will the server, eventually. If ...