Regions and AZs

What Are Regions and AZs?

A region and availability zone (AZ) identify the location of a data center. You can create resources in a specific region and AZ.

• A region is a physical data center, which is completely isolated to improve fault tolerance and stability. After a resource is created, its region cannot be changed.
• An AZ is a physical location where resources use independent power supplies and networks. A region contains one or more AZs that are physically isolated but interconnected through internal networks. Because AZs are isolated from each other, any fault that occurs in an AZ will not affect other AZs.

Figure 1 shows the relationship between regions and AZs.

Figure 1 Regions and AZs

How Do I Select a Region?

Select a region closest to your target users for low network latency and quick access.

How Do I Select an AZ?

When determining whether to deploy resources in the same AZ, consider your applications' requirements for disaster recovery (DR) and network latency.

• For high DR capability, deploy resources in different AZs in the same region.
• For low network latency, deploy resources in the same AZ.

Regions and Endpoints

When using an API to use resources, you must specify its region and endpoint. For details about regions and endpoints, see Regions and Endpoints.