BMC Remedy Single Sign-On HA environment
In a High Availability (HA) environment, multiple instances of the BMC Remedy Single Sign-On web application are deployed and form a cluster. Usually a load balancer is used as a front end to the cluster, giving the external applications the appearance of a single server. The load balancer distributes requests among BMC Remedy Single Sign-On nodes. However, there is no requirement for a sticky session, because requests can be handled by any instance.
When operating as a cluster, BMC Remedy Single Sign-On functions as a single virtual server. Therefore, certain configuration information and user sessions data are stored in the database and shared (not replicated) between nodes. For example, when one node is configured, the other nodes have the same information.
The following information is global to all nodes in a cluster:
- Administrative accounts
- Configuration of the authentication providers
- Branding-related data
- Issued tokens and user-session data
Role of the database
No state is stored in the BMC Remedy Single Sign-On web applications. The local (file-based) information is almost totally absent in the BMC Remedy Single Sign-On cluster (except database connection information - which is usually also the same). All configuration data, sessions, and user tokens are persisted in the database and loaded from the database. To prevent the database from becoming a single point of failure, database replication may require, but the specific settings depend on the specific environment. Therefore, database replication is out of scope of the BMC Remedy Single Sign-On documentation.