Amazon Web Services in Action, Third Edition

Part 3. Storing data in the cloud

There is one guy named Singleton in your office who knows all about your file server. If Singleton is out of office, no one else can maintain the file server. As you can imagine, while Singleton is on vacation, the file server crashes. No one else knows where the backup is located, but the boss needs a 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 information is unavailable.

Imagine a virtual machine where important files are located on hard disk. As long as the virtual machine is up and running, everything is fine. But everything fails all the time, ...