receives this information in real time from the BlackBerry Enterprise Server instance so that the failover status is always up-
to-date.
How the BlackBerry Enterprise Server useshealth parameters
The BlackBerry Enterprise Server uses health parameters to define the failover and promotion thresholds. The health
parameters indicate if a BlackBerry Enterprise Server service or component is healthy or unhealthy. For example, the value
for the Wireless network access health parameter indicates whether the BlackBerry Router can access the wireless
network. The health parameters are identical for both the failover threshold and the promotion threshold. You can choose
the health parameters for the services and components that are important to your organization.
After you choose the health parameters that you want the BlackBerry Enterprise Server to use to determine when an
automatic failover process should occur, the failover process can occur automatically if all of the following conditions are
present:
• The values for the health parameters that you define as part of the failover threshold for the primary BlackBerry
Enterprise Server indicates whether a service or component is unhealthy.
• The values for the health parameters that you define as part of the promotion threshold for the standby BlackBerry
Enterprise Server indicate whether all the required services and components are healthy.
• If you configure a health parameter for the primary BlackBerry Enterprise Server so that it is above the failover
threshold, the health parameter value must indicate that the BlackBerry Enterprise Server service or component is
healthy on the standby BlackBerry Enterprise Server before the automatic failover process can occur, even if you
configure the health parameter to be below the promotion threshold line.
You must configure the health parameters that you choose for the primary BlackBerry Enterprise Server so that they are
above the failover threshold. You must configure the health parameters that you choose for the standby BlackBerry
Enterprise Server so that they are above the promotion threshold. The BlackBerry Enterprise Server ignores the health
parameters that you configure to be below the thresholds.
The BlackBerry Enterprise Server updates the values of the health parameters periodically so that the BlackBerry
Enterprise Server can determine automatically when a failover process should occur.

Defining when failover occurs

How you configure the failover threshold and promotion threshold impacts when failover occurs. You can configure the
thresholds in any of the following ways:
• For failover to occur when the standby BlackBerry Enterprise Server is in an acceptable state, you can move the
promotion threshold so that it is higher than the failover threshold. An acceptable state provides only the BlackBerry
services that your organization considers essential.
Administration Guide Configuring BlackBerry Enterprise Server high availability
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