Concepts
Regions and availability zones (AZs) identify the locations of data centers. You can create resources in regions and AZs.
- A region is a physical data center location. Each region is completely independent, maximizing the fault tolerance capability and stability. After you create resources in a region, the region cannot be changed.
- An AZ is a physical location with independent power supplies and network in a region. A region can contain multiple AZs that are physically isolated but internally interconnected. Faults that occur in one AZ will not affect other AZs. The inter-AZ connections are low-latency and unexpensive.
Figure 1 shows the relationship between regions and AZs.
Selecting a Region
You are advised to select a region close to you or your target users to reduce network latency and improve the access speed.
Selecting an AZ
When selecting a region to deploy resources, consider your applications' requirements on disaster recovery (DR) and network latency.
- For robust DR, deploy resources in different AZs within the same region.
- For a low network latency, deploy resources in the same AZ.
Regions and Endpoints
Before you use an API to call resources, specify its region and endpoint. For more information, see Regions and Endpoints.