Half an hour downtime once a week? This sounds bad.
Here are the exact words from Amazon:
> The Amazon RDS maintenance window is your opportunity to control when DB Instance modifications (such as scaling DB Instance class) and software patching occur, in the event they are requested or required. If a maintenance event is scheduled for a given week, it will be initiated and completed at some point during the maintenance window you identify. Maintenance windows are 30 minutes in duration. The only maintenance events that require Amazon RDS to take your DB Instance offline are scale compute operations (which generally take only a few minutes from start-to-finish) or required software patching. Required patching is automatically scheduled only for patches that are security and durability related. Such patching occurs infrequently (typically once every few months) and should seldom require more than a fraction of your maintenance window. If you do not specify a preferred weekly maintenance window when creating your DB Instance, a 30 minute default value is assigned. If you wish to modify when maintenance is performed on your behalf, you can do so by modifying your DB Instance in the AWS Management Console, the ModifyDBInstance API or the modify-db-instance command. Each of your DB Instances can have different preferred maintenance windows, if you so choose.
Running your DB Instance as a Multi-AZ deployment can further reduce the impact of a maintenance event. Please refer to the Amazon RDS User Guide for more information on maintenance operations.
