What Are Regions and AZs?

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.

• Regions are divided based on geographical location and network latency. Services, such as ECS, EVS, OBS, VPC, Elastic IP (EIP), and Image Management Service (IMS), can be shared within the same region. There are two types of regions: universal and dedicated. A universal region provides cloud services for all tenants. A dedicated region only provides a certain type of services or only provides services for specific tenants.
• An AZ contains one or more physical data centers. Each AZ has independent cooling, fire extinguishing, moisture-control, and electricity facilities. Within an AZ, computing, network, storage, and other resources are logically divided into multiple clusters. AZs within a region are interconnected using high-speed optical fibers to support cross-AZ high-availability systems.

Figure 1 shows the relationship between regions and AZs.

Figure 1 Regions and AZs

Region Selection

You are advised to select a region close to you or your target users. This reduces network latency and improves the access success rate.

AZ Selection

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

• To prioritize DR capabilities, deploy resources in different AZs in the same region.
• To prioritize network latency, deploy resources in the same AZ.

Regions and Endpoints

Before using an API to call resources, you will need to specify the resource region and endpoint. For details, see "Endpoints" in Cloud Search Service API Reference.