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Updated on 2025-05-22 GMT+08:00
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RES03-02 Synchronizing Data Across AZs

Stateful services require data synchronization between AZs to prevent data loss during an AZ failure. Stateless services do not need this synchronization.

  • Risk level

    High

  • Key strategies
    • If the cloud service for an application component supports cross-AZ HA instances, enable the cross-AZ data synchronization of the cloud service, such as RDS databases, DCS instances, or OBS buckets.
    • If the cloud service for an application component does not support cross-AZ HA instances but supports cross-AZ data synchronization through a synchronization service, use that service to synchronize data across AZs. For example, ECSs with stateful data do not support cross-AZ HA, but Storage Disaster Recovery Service (SDRS) can be used for cross-AZ data synchronization.
    • If the cloud service for an application component does not support cross-AZ HA instances and does not support or use cross-AZ data synchronization, such as BMSs with stateful data, replicate data at the application layer.
  • Related cloud services and tools
    • Storage Disaster Recovery Service (SDRS)
    • ECS
    • RDS
    • DCS
    • OBS
Parent topic: RES03 Cross-AZ DR