What Are the Differences Between Single-AZ and Dual-AZ DRS Tasks?

You can set DRS Task Type to Single-AZ or Dual-AZ when creating a DRS real-time synchronization task.

• Dual-AZ: This architecture provides HA, improving the reliability of DRS tasks. After a dual-AZ task is created, DRS creates two subtasks, each running in the primary and standby AZs. If the subtask in the primary AZ fails, DRS automatically starts the subtask in the standby AZ to continue the synchronization. This deployment is for scenarios where there is a lot of service data, long-term synchronization is required, and there are strict limits on how much service downtime can be tolerated.
• Single-AZ: Single-node deployment is used. The synchronization task will be created on only one node to save money. This deployment is for scenarios where there is a small amount of service data, short-term synchronization is required, and there is no requirement on service downtime.

This option is available only in specific scenarios. For details, see Performing a Switchover for a Dual-AZ Task.