This topic provides answers to some frequently asked questions about the regions and zones of ApsaraDB RDS.
Introduction to regions and zones
A region is a physical data center. After an ApsaraDB RDS instance is created, you cannot change the region of the RDS instance.
Zones in a region are physical areas with independent power supplies and network facilities. The network latency between instances that reside in the same zone is lower than the network latency between instances that reside in different zones.
Can an ECS instance and an ApsaraDB RDS instance that reside in different regions communicate with each other? Am I charged for traffic that is consumed to establish the connections between the instances?
Yes, instances in different regions can communicate with each other over the Internet by using public endpoints. For more information, see View and change the internal and public endpoints and port numbers of an ApsaraDB RDS for MySQL instance. The performance, security, and stability of Internet-based connections are poor. Internet traffic is free of charge. By default, instances in different regions cannot communicate with each other over an internal network. If you want to enable communication between the instances in different regions over an internal network, you can use one of the following methods:
Method 1: Release one of the two instances and re-create the instance that you released in the region where the other instance resides.
Method 2: Change the network types of the Elastic Compute Service (ECS) instance and the RDS instance to VPC. Then, use Cloud Enterprise Network (CEN) to establish a connection between the VPC of the ECS instance and the VPC of the RDS instance. For more information, see Change the network type of an ApsaraDB RDS instance and Use CEN to enable intra-region network communication.
Can instances in different zones of the same region communicate over an internal network?
Yes, instances in different zones of the same region can communicate over an internal network by using internal endpoints. For more information, see View and change the internal and public endpoints and port numbers of an ApsaraDB RDS for MySQL instance.
Can I change the region of my RDS instance?
No, you cannot change the region of your RDS instance after you confirm the purchase order. However, you can use Alibaba Cloud Data Transmission Service (DTS) to migrate the data of your original RDS instance to a different RDS instance in the destination region. Then, you can release your original RDS instance. For more information, see Overview of data migration scenarios and Release or unsubscribe from an ApsaraDB RDS for MySQL instance.
Can I change the zone of my RDS instance?
Yes, you can change the zone of your RDS instance. However, zones in the same region do not have significant differences. You do not need to change the zone of your RDS instance. If you want to change the zone of your RDS instance due to specific reasons, see Migrate an ApsaraDB RDS for MySQL instance across zones.
Which deployment method is recommended: single-zone deployment or multi-zone deployment?
Zones in the same region are independent physical areas that are accessible to each another over an internal network. If a zone is down, other zones are not affected. If your application requires high disaster recovery capabilities, we recommend that you use the multi-zone deployment method.
For more information, see Create an ApsaraDB RDS for MySQL instance.