Validating Regional-DR with applications

Regional disaster recovery (Regional-DR) supports disaster recovery of applications deployed on managed clusters regardless of whether the Red Hat® Advanced Cluster Management (RHACM) manages the applications or not. It also supports disaster recovery of virtual machines (VMs).

After successfully configuring Regional-DR on the managed clusters, you can validate the setup by replicating and recovering applications across those clusters.

Applications are categorized as follows:
  • Managed applications: Workloads deployed and managed through RHACM, such as Subscription-based and ApplicationSet-based applications.
  • Discovered applications: Workloads deployed directly on one of the managed clusters without using RHACM. Although these applications are appear in the RHACM console, their lifecycle (create, edit, delete) is not managed by RHACM.

To validate with VMs, if the VM is configured with a secondary VLAN in the IBM Fusion HCI site, ensure that the same secondary VLAN is configured and a corresponding Network Attachment Definition (NAD) is created on the other site. For the secondary VLAN configuration, see Provisioning additional networking.

Validate Regional-DR with the following applications:

ApplicationSet-based application

To validate Regional-DR with a Subscription-based application, do as follows:
  1. Create a sample ApplicationSet-based application by following the instructions mentioned in Creating an ApplicationSet-based application.
  2. Apply the DRPolicy to the sample application by following the instructions mentioned in Applying DRpolicy to an ApplicationSet-based application.
  3. Do the failover operation of the sample application between the managed clusters by following the instructions mentioned in Subscription-based application failover between managed clusters.
  4. Do the relocate operation of the sample application between the managed clusters by following the instructions mentioned in Relocating an ApplicationSet-based application between managed clusters.

After validation, you can delete the sample application by following the instructions mentioned in Deleting a sample application.

Subscription-based application

To validate Regional-DR with a Subscription-based application, do as follows:
  1. Create a sample Subscription-based application by following the instructions mentioned in Creating a Subscription-based application.
  2. Apply the disaster recovery policy (DRPolicy) to the sample application by following the instructions mentioned in Applying DRPolicy to a Subscription-based application.
  3. Do the failover operation of the sample application between the managed clusters by following the instructions mentioned in Subscription-based application failover between managed clusters.
  4. Do the relocate operation of the sample application between the managed clusters by following the instructions mentioned in Relocating a Subscription-based application between managed clusters.

After validation, you can delete the sample application by following the instructions mentioned in Deleting a sample application.

Discovered application

To validate Regional-DR with a discovered application, do as follows:
  1. Ensure that all prerequisites mentioned in Prerequisites for disaster recovery protection of discovered applications are met.
  2. Create a sample discovered application by following the instructions mentioned in Creating a sample discovered application.
  3. Enroll the DRPolicy to the sample application by following the instructions mentioned in Enrolling a sample discovered application for disaster recovery protection.
  4. Do the failover operation of the sample application between the managed clusters by following the instructions mentioned in Failover disaster recovery protected discovered application.
  5. Do the relocate operation of the sample application between the managed clusters by following the instructions mentioned in Relocate disaster recovery protected discovered application.

While the Backup & Restore service and Regional‑DR can be configured for the same application, the Backup & Restore service does not currently recognize the disaster recovery state of an application. Even when a hub and spoke configuration is used between two sites, a failed-over application is treated by the Backup & Restore service as a new application.

As a result:

  • The Backup & Restore service continues to attempt scheduled backups for the original application on site 1, which might require manual disabling.
  • The failed‑over application on site 2 does not inherit Backup & Restore service protection from site 1. The application remains unprotected until a new PolicyAssignment custom resource (CR) is created. Backups created for the application on site 2 are independent of the backups created for the same application on site 1.

To configure Backup & Restore service in a Regional‑DR configuration, complete the following steps:

  1. Enroll the application for both Regional‑DR and the Backup & Restore service.
  2. Fail over the application from site 1 to site 2.
  3. Delete the PolicyAssignment CR for the application on site 1 to prevent scheduled backups.
  4. Relocate the application from site 2 back to site 1.
  5. Create a new PolicyAssignment CR for the application on site 1 to resume backups.

After validation, you can delete the sample application by following the instructions mentioned in Disable disaster recovery for protected applications.