[98codes]

Companies can architect their backends to be able to fail back to another region in case of outage, and either don't test it or don't bother to have it in place because they can just blame Amazon, and don't otherwise have an SLA for their service.

To fix it, test your failback procedures. For everything else, there's nothing to fix, it's working by design.

[maccard]

> Companies can architect their backends to be able to fail back to another region in case of outage, and either don't test it or don't bother to have it in place because they can just blame Amazon, and don't otherwise have an SLA for their service.

My CI was down for 2 hours this morning, despite not even being on AWS. We have a set of credentials on that host that we call assumeRole with and push to an S3 bucket, which has a lambda that duplicates to buckets in other regions. All our IAM calls were failing due to this outage, and we have 0 items deployed in us-east-1 (we're european)

[cyberax]

You likely used a us-east-1 IAM endpoint instead of a regionalized one ( https://aws.amazon.com/blogs/security/how-to-use-regional-aw... ). We've been using it, and we're not experiencing any issues whatsoever in us-east-2.

One thing that AWS should do is provide an easier way to detect these hidden dependencies. You can do that with CloudTrail if you know how to do it (filter operations by region and check that none are in us-east-1), but a more explicit service would be nice.