03-02 Availability Zone
An Availability Zone (AV) is a physical location made up of one or more data centers.
A datacenter is a secured building that contains hundreds of thousands of computers. ^b2786e
A region will generally contain 3 Availability Zones
Data-centers within a region will be isolated from each other (different buildings) but they will be close enough to provide low-latency (< 10ms).
Note
Its common practice to run workloads in at least 3 AVs to ensure services remain available in case one or two data-centers fail.
AZs are represented by a Region Code, followed by a letter identifier e.g. us-east-1a
- A Subnet is associated with an Availability Zone.
- You never choose the the AZ when launching resources.
- You choose the Subnet which is associated to an AZ.