4 ms·

Interesting, but Amazon doesn't guarantee most of those things. They guarantee a 99.99% uptime, but that isn't counting a complete datacenter failure. In fact,

by skolor 17y ago

Interesting, but Amazon doesn't guarantee most of those things. They guarantee a 99.99% uptime, but that isn't counting a complete datacenter failure. In fact, it sounds to me as if they have a similar set up to the backblaze people. 99.99% uptime means roughly 1 hour per year of downtime. I don't know what the specific failure rates on the components are, but it seems reasonable that A) the data drives are hot-swappable, and will not cause downtime when they are replaced and B) the rest of the components fail once a year (or less) and take ~10 minutes to replace and reboot the system. With 4 main places of failure (PSU, Boot Drive, Motherboard/Ram/CPU, Drive controllers), as long as you have staff constantly on call and they can respond within 5 minutes of a failure, 99.99% uptime seems reasonable. I don't know where you got the idea that your data was on 4 different servers when using S3. I can't find even the slightest amount of information on that. Yes, that would be nice, and it is cool to think that, but its rather doubtful that they're actually doing that (or they could probably add another 9 to their uptime).

ShabbyDoo 17y ago
>but that isn't counting a complete datacenter failure I believe that S3 replicates to multiple physical locations. So, while you might experience downtime, you probably won't experience data loss.
lecha 17y ago
Re. geographical redundancy, see comment http://news.ycombinator.com/item?id=422574 http://news.ycombinator.com/item?id=422574 : "Amazon keeps at least 3 copies of your data (which is what you need for high reliability) in at least 2 different geographical locations. " I can't find the original source supporting that statement, but I also know it to be true based on direct contact with AWS team. (I'm using AWS since private alpha of EC2 in 2005)
- skolor 17y ago
  I can't find that anywhere either, and would be interested in seing it. In fact, all I can find is: A bucket can be located in the United States or in Europe. All objects within the bucket will be stored in the bucket’s location, but the objects can be accessed from anywhere. which seem to imply that your data is located in one location, not 2. In addition, looking at the actual S3 contract, they're really only guaranteeing at 99.9% uptime, which allows for up to 8 hours of downtime a year, more than enough to completely re-build the outer server once a year, as long as they can keep the data intact (which they seem more than capable of with their setup, once again assuming their data center is not completely destroyed).

by skolor 17y ago

ShabbyDoo 17y ago

>but that isn't counting a complete datacenter failure I believe that S3 replicates to multiple physical locations. So, while you might experience downtime, you probably won't experience data loss.

lecha 17y ago

Re. geographical redundancy, see comment http://news.ycombinator.com/item?id=422574 http://news.ycombinator.com/item?id=422574 : "Amazon keeps at least 3 copies of your data (which is what you need for high reliability) in at least 2 different geographical locations. " I can't find the original source supporting that statement, but I also know it to be true based on direct contact with AWS team. (I'm using AWS since private alpha of EC2 in 2005)

skolor 17y ago
I can't find that anywhere either, and would be interested in seing it. In fact, all I can find is: A bucket can be located in the United States or in Europe. All objects within the bucket will be stored in the bucket’s location, but the objects can be accessed from anywhere. which seem to imply that your data is located in one location, not 2. In addition, looking at the actual S3 contract, they're really only guaranteeing at 99.9% uptime, which allows for up to 8 hours of downtime a year, more than enough to completely re-build the outer server once a year, as long as they can keep the data intact (which they seem more than capable of with their setup, once again assuming their data center is not completely destroyed).