Switching to passive hub cluster

About this task

Use this procedure when active hub is down or unreachable.

Procedure

  1. Restore the backups on the passive hub cluster. For information, see Restoring a hub cluster from backup.
    Important: Recovering a failed hub to its passive instance will only restore applications and their DR protected state to its last scheduled backup. Any application that was DR protected after the last scheduled backup would need to be protected again on the new hub.
  2. Verify that the Primary and Seconday managed clusters are successfully imported into the RHACM console and they are accessible. If any of the managed clusters are down or unreachable then they will not be successfully imported.
  3. Wait until DRPolicy validation succeeds.
  4. Verify that the DRPolicy is created successfully. Run this command on the Hub cluster for each of the DRPolicy resources created, where <drpolicy_name> is replaced with a unique name. 
    oc get drpolicy <drpolicy_name> -o jsonpath='{.status.conditions[].reason}{"\n"}'

    Example output:

    Succeeded
  5. Refresh the RHACM console to make the DR monitoring dashboard tab accessible if it was enabled on the Active hub cluster.
  6. If only the active hub cluster is down, restore the hub by performing hub recovery, and restoring the backups on the passive hub. If the managed clusters are still accessible, no further action is required.
  7. If the primary managed cluster is down, along with the active hub cluster, you need to fail over the workloads from the primary managed cluster to the secondary managed cluster. For failover instructions, based on your workload type, see Subscription-based application failover between managed clusters or ApplicationSet-based application failover between managed clusters.
  8. Verify that the failover is successful. When the Primary managed cluster is down, then the PROGRESSION status for the workload would be in Cleaning Up phase until the down managed cluster is back online and successfully imported into the RHACM console.
    On the passive hub cluster, run the following command to check the PROGRESSION status.
    oc get drpc -o wide -A
    NAMESPACE      NAME                              AGE   PREFERREDCLUSTER   FAILOVERCLUSTER   DESIREDSTATE   CURRENTSTATE   PROGRESSION   START TIME             DURATION       PEER READY
busybox        busybox-cephfs-placement-1-drpc   42m   ocp4perf1                                           Deployed       Completed     2024-04-18T09:03:05Z   1.044537443s   True