applyImmediately

Specifies whether the modifications in this request and any pending modifications are asynchronously applied as soon as possible, regardless of the PreferredMaintenanceWindow setting for the DB instance. By default, this parameter is disabled.

If this parameter is disabled, changes to the DB instance are applied during the next maintenance window. Some parameter changes can cause an outage and are applied on the next call to RebootDBInstance, or the next failure reboot. Review the table of parameters in Modifying a DB Instance in the Amazon RDS User Guide to see the impact of enabling or disabling ApplyImmediately for each modified parameter and to determine when the changes are applied.