Maintaining Business Continuity - High Availability
Configure one tier as a data repository for backup of critical information or replicate historical data in multiple tiers. Lower tiers can feed higher levels either a complete data stream or just summary, aggregated data. If the system goes down while you are using a data analysis and reporting application such as Historian Client, the system switches automatically to a designated backup historian. When the primary historian comes back online, all connected Historian Client instances switch back automatically to the primary server.