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. Public services, such as ECS, EVS, OBS, VPC, Elastic IP (EIP), and Image Management Service (IMS), are shared within the same region. Regions are classified as universal regions and dedicated regions. A universal region provides universal cloud services for common tenants. A dedicated region provides specific services for specific tenants.
• An AZ contains one or more physical data centers. Each AZ has independent cooling, fire extinguishing, moisture-proof, and electricity facilities. Within an AZ, compute, 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

HUAWEI CLOUD provides services in many regions around the world. You can select a region and AZ as needed.

How Should I Select a Region?

When selecting a region, consider the following factors:

• Geolocation

  You are advised to select a region close to you or your target users. This reduces network latency and improves access speed. However, Chinese mainland regions provide the same infrastructure, BGP network quality, as well as resource operations and configurations. Therefore, if you or your target users are in the Chinese mainland, you do not need to consider the network latency differences when selecting a region.

  • If you or your target users are in the Asia Pacific area (excluding the Chinese mainland), select the CN-Hong Kong, AP-Bangkok, or AP-Singapore region.
  • If you or your target users are in Africa, select the AF-Johannesburg region.
  • If you or your target users are in Europe, select the EU-Paris region.
• Related cloud services

  If you use multiple cloud services together, pay attention to the following constraints:

  • ECSs, RDS instances, and OBS buckets in different regions cannot communicate with each other through an internal network.
  • ECSs in different regions cannot be bound to the same load balancer.
• Resource price

  Resource prices may vary in different regions.

How Should I Select an AZ?

When determining whether to deploy resources in the same AZ, consider your application's requirements on 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 more details, see Regions and Endpoints.