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Backing up across two different regions is possible for any provider with two "regions" but requires either doubling your storage footprint or accepting a laten

Backing up across two different regions is possible for any provider with two "regions" but requires either doubling your storage footprint or accepting a latency hit because you have to make a roundtrip from Fremont to Denver. The neat thing about AWS' AZ architecture is that it's a sweet spot in the middle. They're far enough apart for good isolation, which provides durability and availability, but close enough that the network round trip time is negligible compared to the disk seek. Re: bit rot, I mean the frequency of events. If you've got a few disks, you may see one flip every couple years. They happen frequently enough in S3 that you can have expectations about the arrival rate and alarm when that deviates from expectations.

logifail 3y ago
> The neat thing about AWS' AZ architecture is that it's a sweet spot in the middle What may be less of a sweet spot is AWS' pricing.
- emodendroket 3y ago
  Sending the data to /dev/null is the cheapest option if that’s all you care about.
  - logifail 3y ago
    Seems the snark detector just went off :) Back on topic, I'd hope all of us would expect value for money for any and all services we recommend or purchase. Search for "site:news.ycombinator.com Away From AWS" to find dozens of discussions on how to save money by leaving AWS. EDIT: just one article of the many I've read recently: "What I’ve always found surprising about egress is just how expensive it is. On AWS, downloading a file from S3 to your computer once costs 4 times more than storing it for an entire month" https://robaboukhalil.medium.com/youre-paying-too-much-for-egress-b1fe20274a6b https://robaboukhalil.medium.com/youre-paying-too-much-for-e...
    - looknohandsma 3y ago
      And that is egress which works as expected, unlike the AWS S3 denial of wallet attack...: https://news.ycombinator.com/item?id=39625029 https://news.ycombinator.com/item?id=39625029
senderista 3y ago
> the network round trip time is negligible compared to the disk seek Only for spinning rust, right?
- breckognize 3y ago
  Yes, which is what all the hyperscalers use for object storage. HDD seek time is ~10ms. Inter-az network latency is a few hundred micros.
alexchamberlain 3y ago
> They're far enough apart for good isolation, which provides durability and availability It can't possibly be enough for critical data though, right? I'm guessing a fire in 1 is unlikely to spread to another, but could it affect the availability of another? What about a deliberate attack on the DCs or the utilities supplying the DCs?
- immibis 3y ago
  Yes, if a terrorist blows up all of the several Amazon DCs holding your data, your data will be lost. This is true no matter how many DCs are holding your data, who owns them, or where they are. You can improve your chances, of course. There have been region-wide availability outages before. They're pretty rare and make worldwide news media due to how much of the internet they take out. I don't think there's been S3 data loss since they got serious about preventing S3 data loss.
- rfoo 3y ago
  > but could it affect the availability of another Availability is a different beast than durability. I think people are paranoid here about durability instead of availability. S3 advertises four nines availability and 12 nines durability.

logifail 3y ago

> The neat thing about AWS' AZ architecture is that it's a sweet spot in the middle What may be less of a sweet spot is AWS' pricing.

emodendroket 3y ago
Sending the data to /dev/null is the cheapest option if that’s all you care about.
- logifail 3y ago
  Seems the snark detector just went off :) Back on topic, I'd hope all of us would expect value for money for any and all services we recommend or purchase. Search for "site:news.ycombinator.com Away From AWS" to find dozens of discussions on how to save money by leaving AWS. EDIT: just one article of the many I've read recently: "What I’ve always found surprising about egress is just how expensive it is. On AWS, downloading a file from S3 to your computer once costs 4 times more than storing it for an entire month" https://robaboukhalil.medium.com/youre-paying-too-much-for-egress-b1fe20274a6b https://robaboukhalil.medium.com/youre-paying-too-much-for-e...
  - looknohandsma 3y ago
    And that is egress which works as expected, unlike the AWS S3 denial of wallet attack...: https://news.ycombinator.com/item?id=39625029 https://news.ycombinator.com/item?id=39625029

senderista 3y ago

> the network round trip time is negligible compared to the disk seek Only for spinning rust, right?

breckognize 3y ago
Yes, which is what all the hyperscalers use for object storage. HDD seek time is ~10ms. Inter-az network latency is a few hundred micros.

alexchamberlain 3y ago

> They're far enough apart for good isolation, which provides durability and availability It can't possibly be enough for critical data though, right? I'm guessing a fire in 1 is unlikely to spread to another, but could it affect the availability of another? What about a deliberate attack on the DCs or the utilities supplying the DCs?

immibis 3y ago
Yes, if a terrorist blows up all of the several Amazon DCs holding your data, your data will be lost. This is true no matter how many DCs are holding your data, who owns them, or where they are. You can improve your chances, of course. There have been region-wide availability outages before. They're pretty rare and make worldwide news media due to how much of the internet they take out. I don't think there's been S3 data loss since they got serious about preventing S3 data loss.
rfoo 3y ago
> but could it affect the availability of another Availability is a different beast than durability. I think people are paranoid here about durability instead of availability. S3 advertises four nines availability and 12 nines durability.