Suppose you were to sneak into a datacenter run by Google or Facebook or Twitter and take a pickaxe to a random server. What would happen? Firstly, you would be arrested. But what data would be lost? In all likelihood nothing. You might have rent RAM chips and hard drive platters asunder, but the bits that were previously inside the machine would be safe and sound. How is this possible? Careful and deliberate redundancy. At large internet companies the exact same information lives in several ...
