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Yumi Murakami
DoIt!AttachTheEarOfACat!
Join date: 27 Sep 2005
Posts: 6,860
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02-28-2007 04:42
From: Dina Vanalten How would you feel is you had hundreds of thousands of dollars in a RL bank and they had a computer glitch and you lost your money and all they said was sorry too bad. Well yes, but I'm sure you can understand why your bank doesn't let you "back up" your bank balance onto your local hard disk and then, if something goes wrong, you can just "restore" the balance back to your account.  Linden Labs do do regular backups on their side, but at the moment, the process of restoring one single item from them isn't automatic. If you lose an inventory item and you Bug Report to ask a technician to look at it, that's what they basically do - restore it from their backup. |
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Jopsy Pendragon
Perpetual Outsider
Join date: 15 Jan 2004
Posts: 1,906
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02-28-2007 13:33
Keep in mind there are two things to back up: Things and Changes.
It's one thing to back up someone's bank account balance ... it's quite another to back up all the transaction history that affects that account balance.
We do have backups of our transaction history when we get bank account statements, but there's no way we can prove that transactions did or did not occur between the end of that statement and the current moment without using live data... which is at risk.
The "state" of a sim/region is probably backed up (or checkpointed?) hourly, so that if there's an ungraceful sim crash, LL can bring up a new sim and lose only up to an hour's worth of building. I get the impression that most sim crashes are more graceful failures that can save state, that way when it comes back up (probably on a different server) the latest in-world building isn't lost.
The ASSET server is probably generating transaction logs that are backed up hourly. I doubt they back up the entire asset server every hour, that'd be insane, most of the content doesn't ever change.
The INVENTORY database, that keeps track of who and what has which assets, probably changes a lot more frequently than the asset database... and because it's a database, I doubt they back up the whole thing every hour. (though they probably back up their transaction logs frequently, and back the whole thing up less often because they can re-play transaction logs)
The key is data integrity... and being able to carry on without 'losing' any transactions when bad things happen.
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