BlackBerry Configuration Database high availability

The type of BlackBerry® Configuration Database high availability that you can configure depends on the type of database server that is in your organization's environment.

If your organization's environment includes Microsoft® SQL Server® 2005 SP2 or later, you can configure database mirroring. Database mirroring requires a principal database, a mirror database, and a witness. Although the BlackBerry® Enterprise Server can contact the mirror database, it opens active connections to the principal database only. If the principal database stops responding, the BlackBerry Enterprise Server opens an active connection to the mirror database automatically. Database mirroring provides fault tolerance for the BlackBerry® Enterprise Solution.

If your organization's environment includes a version of Microsoft SQL Server that is earlier than version 2005 SP2, you can configure transactional replication of the BlackBerry Configuration Database and create a replicated BlackBerry Configuration Database. If the BlackBerry Configuration Database stops responding, you must fail over the BlackBerry Enterprise Server to the replicated BlackBerry Configuration Database manually.

For more information about database mirroring, visit www.microsoft.com.

BlackBerry Configuration Database mirroring

The following diagram shows how you can configure the BlackBerry® Configuration Database with principal and mirror instances and a witness for high availability. The BlackBerry® Enterprise Server connects to the principal BlackBerry Configuration Database directly, and can fail over to the mirror BlackBerry Configuration Database if the principal BlackBerry Configuration Database stops responding.

This diagram shows the BlackBerry Configuration Database set up for database mirroring.

The primary BlackBerry Enterprise Server connects to the principal BlackBerry Configuration Database and accesses data from it. The name of the mirror BlackBerry Configuration Database is stored in the Windows® registry of the computers that hosts the primary and standby BlackBerry Enterprise Server instances. The BlackBerry Enterprise Server instances do not connect to the mirror BlackBerry Configuration Database until after the principal BlackBerry Configuration Database stops responding.

The primary BlackBerry Enterprise Server connects to the messaging server and processes the messaging data that it sends to and receives from BlackBerry devices.

The standby BlackBerry Enterprise Server opens standby connections to the principal BlackBerry Configuration Database and the messaging server.

Scenario: What happens after the principal BlackBerry Configuration Database stops responding

If a principal BlackBerry® Configuration Database stops responding, the response of the primary BlackBerry® Enterprise Server depends on whether it can connect to the mirror BlackBerry Configuration Database.

The following responses assume that the messaging server and BlackBerry® Infrastructure are available.

Response of a primary BlackBerry Enterprise Server that can connect to the mirror BlackBerry Configuration Database

  1. The primary BlackBerry Enterprise Server loses its connection to the principal BlackBerry Configuration Database.
  2. The primary BlackBerry Enterprise Server connects to the mirror BlackBerry Configuration Database.
  3. The primary BlackBerry Enterprise Server remains the primary instance.

Response of a primary BlackBerry Enterprise Server that cannot connect to the mirror BlackBerry Configuration Database

  1. The primary BlackBerry Enterprise Server loses its connection to the principal BlackBerry Configuration Database.
  2. The primary BlackBerry Enterprise Server tries to connect to the mirror BlackBerry Configuration Database, but is unsuccessful.
  3. The primary BlackBerry Enterprise Server lowers its health score and continues to provide limited services.
    One of the following events occurs:
    • If the standby BlackBerry Enterprise Server can open a connection to the principal or mirror BlackBerry Configuration Database, it demotes the primary BlackBerry Enterprise Server and promotes itself to become the primary instance.
    • If the standby BlackBerry Enterprise Server cannot open a connection to the principal or mirror BlackBerry Configuration Database, it cannot promote itself. You must resolve any issues before the BlackBerry Enterprise Server pair can recover.

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