High availability configurations are possible for each of the following critical Enterprise RTView components: Historian, Data Server, Display Server and Servlets. Redundant components can be set up to provide backup failover capability for each component or for any individual component considered at risk.

Backup components may be run in hot or warm standby mode. In hot standby mode all global variable definitions, as well as cache and alert definitions, are loaded and activated at start up. In warm standby mode none of these actions are performed, thereby avoiding the overhead of maintaining Alert and Cache data sources until the backup component has become the primary. NOTE: User interactions with Alerts such as Alert Acknowledgment are not maintained when a backup component becomes the primary -- this limitation will be resolved in an upcoming release.

High Availability Historian
The Historian is an application you can configure to store time-stamped data, derived from either raw real-time data or aggregated/transformed data, in a relational database of choice. To provide high availability, it is possible to designate backup Historians to support a failover event. See Running the Historian for details. This high availability solution is intended to be used with a database system that also supports redundancy (through mirroring, clustering, or other techniques) so that any Historian in the redundant group can update the same virtual database.

High Availability Deployments
Details for other high availability configurations depend on the type of deployment selected. The following pages explore five deployment options detailing basic configurations versus high availability configurations. Where applicable, examples are provided on how to configure high availability deployments involving web servers and application servers. These examples use Apache and Tomcat, although other web servers and application servers can be used.