Disaster Recovery - Active/Passive

The deployment model illustrated below extends the High-Availability configuration in the Primary Datacenter with a Disaster Recovery option in a secondary datacenter, marked as DR Datacenter in the diagram below. A reduced number of machines is envisioned for the Disaster Recovery datacenter, considering that it is provisioned for temporary use, until the Primary Datacenter is rebuilt. This solution is applicable when there is a slow network connectivity between the data centers.

The following conditions must be met:

• At least one machine from the Always On Availability Group feature is physically located in the Disaster Recovery Datacenter
• There is network connectivity between the Primary Datacenter and the Disaster Recovery Datacenter
• External storage is provided in the Disaster Recovery Datacenter for the snapshots created in the Primary Datacenter using the Snapshot tool. These snapshots are read and applied using the Restore tool on the Elasticsearch indexes located in the Disaster Recovery Datacenter.
• Automation packages (artifacts), having the NuGet format, are stored in the External Storage. Each Orchestrator instance points to this storage with the use of NuGet.Packages.Path configuration setting.
• The High Availability add-on cluster is provided to scaleout SignalR and cache settings and users permissions.

• The External Storage is mirrored (optional - not included in the diagram).

  Note: The Snapshot and Restore tools mentioned above are provided by Elasticsearch. See here for details.