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Updated on 2025-05-22 GMT+08:00
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RES04-02 Deploying a DR System to Meet the DR Objectives

Choose the right DR plan for each application system based on the DR objectives by considering the interruption probability and DR costs.

  • Risk level

    High

  • Key strategies

    In cross-region or cross-cloud DR scenarios, use a proper DR plan like remote backup, active/standby DR, or active-active DR, based on the availability needs. Deploy the production site on another cloud, in an IDC, or in a Huawei Cloud region as required.

    • Remote backup: Back up important data from the production site to a remote Huawei Cloud DR region. In case of a disaster at the production site, deploy a new service system in the remote DR region and use the latest backup data to restore data and services.
    • Active/Standby DR: Deploy a service system at both the production site and Huawei Cloud DR region. Replicate important data from the production site to the DR region asynchronously. Normally, the production site handles all services. In case of a disaster at the production site, the DR region is promoted to the primary site, and service traffic is switched to it.
    • Active-active or multi-active DR: Deploy a service system at both the production site and the Huawei Cloud DR region. Replicate important data between the sites asynchronously. Both sites provide services at the same time, with a global load balancer distributing traffic. If one site fails, the other takes over services seamlessly.

    To support cross-region active/standby DR for a region with an application system deployed, perform the following steps:

    1. Select another region as the DR region and deploy a set of the same application system with its workloads and database instances.
    2. Replicate key data between regions using either a cloud service or the application system.
      • If cloud service instances allow cross-region DR, replicate data between the production site and the DR region. For example, for RDS database instances, apply for a DRS instance to replicate data between the primary region and the DR region in real time. For OBS buckets, replicate their data from the primary region to the DR region.
      • If cloud service instances do not allow cross-region DR but have critical data, enable cross-region data dual-write at the application layer to synchronize data.
    3. Apply for an external IP address for both the primary region and DR region, respectively, on the access side. Use DNS to resolve the application system to the external IP address in the primary region. If the primary region fails, update the DNS record to direct traffic to the external IP address of the DR region.
    4. Use the MAS service for DR orchestration to quickly switch services between the active and standby sites in case of a disaster.
  • Related cloud services and tools
    • Cloud Backup and Recovery (CBR): allows data replication and recovery across regions.
    • Data Replication Service (DRS): allows real-time DR for databases such as RDS for MySQL and GaussDB(for MySQL). It supports both cross-region and cross-cloud DR scenarios.
    • Object Storage Service (OBS): supports cross-region replication and active-active DR.