I’m familiar with Lambda and DynamoDB. When I left in 2022 they both had strong automated or semi-automated AZ evacuation stories.
I’m not that familiar with S3, but I never noticed any concerns with S3 during an AZ outage. I’m not at all familiar with Aurora Serverless or ECS.
For all AWS services you can always ask AWS Support pointed, specific questions about availability. They usually defer to the service team and they’ll give you their perspective.
Also keep in mind that AWS teams differentiate between the availability of their control and data planes. During an AZ outage you may struggle to create/delete resources until an AZ evacuation is completed internally, but already created resources should always meet the public SLA. That’s why especially for DR I recommend active-active or active-“pilot light”, have everything created in all AZs/regions and don’t need to create resources in your DR plan.
Okay good to know - Lambda seemed to suggest it could handle an availability zone going down without any trouble.
ECS Fargate's default is to distribute task instances across availability zones too but I'm assume if you use EC2 it might not be as straight-forward.
And that makes sense - I remember during the last outage that affected me it was a compute rather than data failure and the running stuff continued fine, just nothing new was getting created.
I’m not that familiar with S3, but I never noticed any concerns with S3 during an AZ outage. I’m not at all familiar with Aurora Serverless or ECS.
For all AWS services you can always ask AWS Support pointed, specific questions about availability. They usually defer to the service team and they’ll give you their perspective.
Also keep in mind that AWS teams differentiate between the availability of their control and data planes. During an AZ outage you may struggle to create/delete resources until an AZ evacuation is completed internally, but already created resources should always meet the public SLA. That’s why especially for DR I recommend active-active or active-“pilot light”, have everything created in all AZs/regions and don’t need to create resources in your DR plan.