[aidos]

I recall reading somewhere many years ago that AWS randomise a, b, c etc per account. Otherwise people have a tendency to pick A and be done with it.

[danielhunt]

That's true - they loadbalance instance creation unless you specifically ask for an instance in a zone

That doesn't apply here though. Instances that are already up are experiencing DNS resolution issues because the Amazon-provided DNS service (which is distinct from Route53) is failing

[aidos]

I don't think I explained that very clearly.

What you see as zone A is not what I see as zone A (maybe). When you sign up for an account, AWS assigns your zone A to one of the 3 available zones:

    zone X (real) : your A (virtual) : my C (virtual)
    zone Y (real) : your B (virtual) : my B (virtual)
    zone Z (real) : your C (virtual) : my A (virtual)

That's why people see different outage characteristics between the zones.

Edit: one of the few articles (other than HN comments) that explains it https://alestic.com/2009/07/ec2-availability-zones/

[danielhunt]

I've been using AWS for years and this is the first I've ever heard of this.

All I can say is "WHAAAAAAT?!"

You've made me question my reality. Take an upvote for that alone.

[misframer]

It's in the documentation [0].

    An Availability Zone is represented by a region code followed by a letter identifier;
    for example, us-east-1a. To ensure that resources are distributed across the Availability
    Zones for a region, we independently map Availability Zones to identifiers for each
    account. For example, your Availability Zone us-east-1a might not be the same location
    as us-east-1a for another account. There's no way for you to coordinate Availability
    Zones between accounts.

[0] http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/using-reg...

[aidos]

I'm glad I could make what is otherwise a bad time to be looking after servers a little more enjoyable.

I myself was in the middle of a release when all this happened. "I'll just release this thing" I said, "will only take 20 minutes" I said....