Recovering after Disaster

Add these steps to your enterprise's comprehensive plan for switching business operations to the disaster recovery site. When disaster disables the main site, administrators complete these steps as part of the comprehensive plan.

    Procedure
  1. Optional. Remap DNS addresses.
    If your disaster recover plan includes remapping the DNS addresses of FTL servers, then complete that remapping first.
  2. Issue the activate_dr command at the standby site. From this point on, the drfor parameter in the standby configuration file will be ignored, even if the FTL servers are restarted. Optionally remove the drfor parameter from the configuration file. For details on activate_dr, see POST cluster. For details on drfor, see FTL Server Configuration Parameters.
  3. Modify the primary set of each persistence cluster.
    In the persistence clusters grid of the FTL server GUI, change the primary set of each participating cluster so that the persistence services at the disaster recovery site become the primary set. Disable DR replication by clearing DR Enabled at the cluster level. See Clusters Grid.

    Deploy the modified realm definition.

    You may use the following for reference:

    • samples/yaml/dr/dr-cluster-sample-dr-activate.json

    • samples/yaml/dr-secure/dr-cluster-sample-dr-activate.json

  4. Ensure that the persistence services at the disaster recovery site form a quorum.
    In the persistence clusters status table, verify that the cluster status is Running. In the services list sub-tables, verify that all the services in the cluster are synchronized.

    If the cluster cannot form a quorum, clients cannot connect to its services. Consider forcing a quorum; see Before Forcing a Quorum.

  5. Direct application clients to FTL servers at the disaster recovery site.
    Choose only one of these two alternatives:
    If you remapped the DNS addresses of FTL servers:
    • Verify that the new DNS information has propagated.
    • Verify that all clients automatically connect or reconnect to FTL servers at the disaster recovery site, and are operating correctly.
    Otherwise, when you restart all application clients, explicitly supply the locations of the new FTL servers where the clients can access realm services and persistence services.
    The disaster recovery site is now the new active site of FTL operations.