Technical Note : How to change the HA cluster age difference margin

In a HA cluster, some of the cluster units may take longer to start up than others. This startup time difference can happen as a result of a number of issues and does not affect the normal operation of the cluster. To make sure that cluster units that start more slowly can still become primary units, by default the FGCP ignores age difference of up to 5 minutes (300 seconds).

It may be required to reduce the margin if during failover testing you do not want to wait the default age difference margin or allow uninterruptable upgrades to work.

The cluster age difference margin can be changed by using the following command:

# config system ha # set ha-uptime-diff-margin 60 # end

This command sets the cluster age difference margin to 60 seconds.

The age difference margin may be in the range from 1 to 65535 seconds.