Disaster Recovery
You can use the disaster recovery feature to resume FTL communications after the main operations site becomes disabled. Application systems can continue after the interruption using replicated persistence data at a remote disaster recovery site.
Prepared for Disaster
The first diagram illustrates a set of FTL servers configured to prepare for recovery from a potential disaster, along with the services they provide and the application processes that they serve. Servers at the main site are on the left (green). Components at the disaster recovery site are on the right (orange).
At each site, each of three core FTL servers explicitly provides a realm service (blue pentagon). Similarly, three auxiliary servers provide a cluster of persistence services (purple hexagons).
Application processes run only at the main site. An application can connect to any local core server (blue lines).
For persistence functionality, the core servers direct applications to the local auxiliary server that provides the persistence cluster leader (red ellipse).
Within each site, the realm services and persistence services synchronize to the state of the local cluster leaders.
The cluster leaders at the two sites communicate via WAN link, to synchronize the disaster recovery site with the latest realm definition and persistence data.
After Recovery
The disaster recovery site now operates as the new main site. Applications connect to the primary servers and communicate with the persistence service in the cluster leader (red ellipse).
Administrators can begin to set up another disaster recovery site.