Why is it more expensive to deploy in zones X,Y in regions A,B than zones M,N in region C? I assume you don't just mean "US West is ~10% more expensive than US East."
It's the combination of the extra cost of having machines in US West plus the cost of keeping the data synchronized between them (which is a lot) plus the added development overhead of making sure that things work cross region.
We'll get there one day, but we aren't there yet.
> but this failure hit multiple AZs.
Gah! You can't always account for all the failure modes that Amazon might have.
Re:Amazon Web Services are down
by asymptotic on Thursday April 21, 2011 @09:39AM
(#2470550)
This seems to be a prevalent misunderstanding. Amazon's EC2 SLA of 99.95% applies at the scope of a region. A region may contain more than one availability zone. Hence, deploying on multiple availability zones still only affords the 99.95% availability level.
Yes, multi-region availability on AWS is hideously expensive. However, some organisations value an availability of greater than 99.95% enough to warrant such a multi-region deployment. Clearly reddit, and many, many other AWS users, do not. This isn't a value call on my part; I definitely couldn't afford the inter-region data transfer costs, all I know is that AWS offers you the tools to deploy high availability web services.
We do.
> they would have chosen to deploy across more than one region.
It's far too costly to do that. We are deployed across multiple AZs, but this failure hit multiple AZs.