tencent cloud

Regions

Overview

A region is the physical location of an IDC. In Tencent Cloud, regions are fully isolated from each other, ensuring cross-region stability and fault tolerance. We recommend that you choose the region closest to your end users to minimize access latency and improve access speed.

You can view the following table or use the DescribeRegions API to get a complete region list.

Characteristics

• The networks of different regions are fully isolated. Tencent Cloud services in different regions cannot communicate via a private network by default.
• Tencent Cloud services across regions can communicate with each other through public IPs over the Internet, while those in different VPCs can communicate with each other through CCN, which is faster and more stable.
• [Cloud Load Balancer (CLB)(https://intl.cloud.tencent.com/document/product/214) currently supports intra-region traffic forwarding by default. If you enable the Cross-Region Binding 2.0 (New) feature, cross-region binding of CLB and CVM instances is supported.

Availability Zone

Overview

Availability zones (Zone) refer to Tencent Cloud's physical data centers whose power and network are independent from each other within the same region. They are designed to ensure that failures within an availability zone can be isolated (except for large-scale disaster or major power failure) without spreading to other zones, so as to ensure your business stability. By starting an instance in an independent availability zone, users can protect their applications from being affected by the failures occurring in a single location.
You can view the following table or use the DescribeZones API to get a complete availability zone list.

Characteristics

Tencent Cloud services in the same VPC are interconnected via the private network, which means they can communicate using private IPs, even if they are in different availability zones of the same region.

Note：

Private network interconnection refers to the interconnection of resources under the same account. Resources under different accounts are completely isolated on the private network.

China

Other countries and regions

How to select the region and availability zone

When selecting a region and availability zone, take the following into consideration:

• Your location, the location of your users, and the region of the CVM instances.
  We recommend that you choose the region closest to your end users when purchasing CVM instances to minimize access latency and improve access speed.
• Other Tencent Cloud services you use.
  When you select other Tencent Cloud services, we recommend you try to locate them all in the same region and availability zone to allow them to communicate with each other through the private network, reducing access latency and increasing access speed.
• High availability and disaster recovery.
  Even if you have just one VPC, we still recommend that you deploy your businesses in different availability zones to prevent a single point of failure and enable cross-AZ disaster recovery.
• There may be network latency among different availability zones. We recommend that you assess your business requirements and find the optimal balance between high availability and low latency.

Resource Availability

The following table describes which Tencent Cloud resources are global, which are regional, and which are specific to availability zones.

References

Migrating an instance to another availability zone

For an instance that is already started, its availability zone cannot be changed, but its user can migrate it to another availability zone by other means. The migration process involves creating a custom image from the original instance, using the custom image to start an instance in a new availability zone and updating the configuration of the new instance.

1. Create a custom image for the source instance. Creating Custom Images
2. If the network environment of the current instance is VPC and the private IP address must be retained after migration, you need to delete the subnet in the current availability zone and then create a subnet in the new availability zone with the same IP address range as that of the original subnet. Please note that a subnet can be deleted only when it contains no available instance. Thus, all the instances in the current subnet should be migrated to the new subnet.
3. Create a new instance in the new AZ by using the created custom image. You can choose the same type and configuration as those of the original instance, or choose new ones. For more information, see Creating Instances via CVM Purchase Page.
4. If the source instance is associated with an EIP, disassociate the EIP and associate it with the new instance. For more information about shutting down an instance, please see Shutdown Instances.
5. For more information, see Terminating Instances.

Copying images to other regions

Region attribute is differentiated for all behaviors such as enabling and viewing instances by users. If image of the instance that the users need to enable does not exist in the region, then the image needs to be copied to current region. Copying Images