Feature and Technical Overview | BlackBerry Enterprise Server high availability |
The BlackBerry Enterprise Server components calculate their health scores by examining their operating health, the stability of their connections to other components, and the health scores of the other components.
The health score of the BlackBerry Enterprise Server consists of various health parameters. Each health parameter indicates whether a particular service or feature is available. If you turn on the automatic failover feature for the BlackBerry Enterprise Server, you can configure health parameters so that the BlackBerry Enterprise Server fails over automatically when critical services or features are no longer available.
Conditions for failover to a standby BlackBerry Enterprise Server
Failover between the primary and standby BlackBerry Enterprise Server instances occurs when the standby BlackBerry Enterprise Server determines that its health score is above the promotion threshold and one or more of the following events occurred:
•The standby BlackBerry Enterprise Server receives a health score from the primary BlackBerry Enterprise Server that is below the failover threshold.
•The standby BlackBerry Enterprise Server reads, in the BlackBerry Configuration Database, a health score for the primary BlackBerry Enterprise Server that is below the failover threshold.
•The standby BlackBerry Enterprise Server does not receive a response when it checks the BlackBerry Dispatcher for the health score of the primary BlackBerry Enterprise Server.
•The standby BlackBerry Enterprise Server pings the BlackBerry Dispatcher on the network but cannot determine whether the primary BlackBerry Enterprise Server is running.
How a primary BlackBerry Enterprise Server self-demotes
After the primary BlackBerry Enterprise Server receives a request from a standby BlackBerry Enterprise Server to self- demote, the primary BlackBerry Enterprise Server performs the following actions:
•closes its SRP connection to the BlackBerry Infrastructure
•stops the flow of all messages
•stops the Novell GroupWise SOAP connector if your organization's environment includes the BlackBerry Enterprise Server for Novell GroupWise
•demotes its connections to the messaging server and BlackBerry Configuration Database to standby connections
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