Comment 11 for bug 1860083

I think this is a 3-in-1 bug (at least through my testing).

But I believe found the main culprit: We don't handle constraints in AZ retries.
I'm working on a fix now. I've also added additional logging that should highlight retries in the logs.

The other two issues are:
- apne1-az3 capacity/unsupported instance types. Nothing I can do about this.
- We select instance-type that match constraints, but we use AWS pricing data, which is only granular down to region, not AZ. I've fixed this already, we now only select instance-types (for AWS) that are supported across all AZs in a region (unless the user passes an instance-type constraint).