If I save a document using a cloud based service, am I right in thinking that my file will be stored redundantly on a few DAS servers in a local data center. When I try and access this data again, how is my query routed to the server which contains my data, so say a copy of my file is stored on server 7 and server 27. I make my request for my file and somehow this request is routed to server 7 which returns my file. Are the locations of such files stored in a database, if so wouldn't this database server be overwhelmed, causing a single bottle neck at peak times? I don't see how this would be a viable approach.
So how is this implemented in theory with services like Apple's iCloud? How is my query routed appropriately to the server which contains my data amongst the thousands of Apple servers?
Thanks, P.S. Sorry if this is stupid/unclear question.