Standard version and cluster version active/standby DCS Redis instances adopt a deployment architecture with active/standby nodes, and support the deployment of active and standby nodes in different AZs (different physical server rooms). The power and network between different AZs are isolated from each other. When the server room where the active node is located fails due to power or network failure, the standby node takes over the service, and the client can establish a connection with the standby node and read/write data as usual.
The figure above illustrates the cross-AZ deployment of active/standby instances. The cluster version active/standby instances are similar to the active/standby instances, for each shard node is deployed across AZs. When buying a Redis instance, you can choose different AZs for deployment (for resource pools that support cross-AZ deployment only).