isDefault

Whether this is the default traffic distribution group created during instance replication. The default traffic distribution group cannot be deleted by the DeleteTrafficDistributionGroup API. The default traffic distribution group is deleted as part of the process for deleting a replica.

The SignInConfig distribution is available only on a default TrafficDistributionGroup (see the IsDefault parameter in the TrafficDistributionGroup data type). If you call UpdateTrafficDistribution with a modified SignInConfig and a non-default TrafficDistributionGroup, an InvalidRequestException is returned.