Reserved Instances

What are Amazon RDS Reserved Instances?

With Reserved Instances, you can now make a one-time, up-front payment to create a one or three year reservation to run your DB Instance in a specific Region and receive a significant discount off of the ongoing hourly usage charge. There are three Reserved Instance types (Light, Medium, and Heavy Utilization Reserved Instances) that enable you to balance the amount you pay upfront with your effective hourly price.

How are Reserved Instances different from On-Demand DB Instances?

Functionally, Reserved Instances and On-Demand DB Instances are exactly the same. The only difference is how your DB Instance(s) are billed; with Reserved Instances, you make a one-time up-front payment and receive a lower ongoing hourly usage rate (compared with On-Demand DB Instances) for the duration of the term.

How do I purchase and create Reserved Instances?

You can use the "Purchase Reserved DB Instance" option in the AWS Management Console. Alternatively, you can use the API tools, you can list the reservations available for purchase with the DescribeReservedDBInstancesOfferings API method and then purchase a DB Instance reservation by calling the PurchaseReservedDBInstancesOffering method.

Creating a Reserved Instance is no different than launching an On-Demand Instance. You simply use the rds-create-db-instance command, the CreateDBInstance API, or select the Launch DB Instance option from the AWS Management Console, specifying the DB Instance class and Region for which you made the reservation. So long as your reservation purchase was successful, Amazon RDS will apply the reduced hourly rate for which you are eligible to the new DB Instance.

Will there always be reservations available for purchase?

Yes. Reserved Instances are purchased for the Region rather than for the Availability Zone. This means that even if capacity is limited in one Availability Zone, reservations can still be purchased in that Region and used in a different Availability Zone within that Region.

How many Reserved Instances can I purchase?

You can purchase up to 20 Reserved DB Instances. If you wish to run more than 20 DB Instances please complete the Amazon RDS DB Instance request form.

What if I have an existing DB Instance that I’d like to convert to a Reserved Instance?

Simply purchase a DB Instance reservation with the same DB Instance class, DB Engine and License Model within the same Region as the DB Instance you are currently running and would like to reserve. If the reservation purchase is successful, Amazon RDS will automatically apply your new hourly usage charge to your existing DB Instance.

If I sign up for a Reserved Instance, when does the term begin? What happens to my DB Instance when the term ends?

Pricing changes associated with a Reserved Instance are activated once your request is received while the payment authorization is processed. You can follow the status of your reservation on the AWS Account Activity page or by using the DescribeReservedDBInstances API. If the one-time payment cannot be successfully authorized by the next billing period, the discounted price will not take effect.

When your reservation term expires, your Reserved Instance will revert to the appropriate On-Demand hourly usage rate for your DB Instance class and Region.

How do I control which DB Instances are billed at the Reserved Instance rate?

The Amazon RDS APIs for creating, modifying, and deleting DB Instances do not distinguish between On-Demand and Reserved Instances so that you can seamlessly use both. When computing your bill, our system will automatically apply your Reservation(s), such that all eligible DB Instances are charged at the lower hourly Reserved DB Instance rate.

If I scale my Reserved Instance class up or down, what happens to my reservation?

Each reservation is associated with the following set of attributes: DB Engine, DB Instance class, Deployment type, License Model and Region. Each reservation can only be applied to a DB Instance with the same attributes for the duration of the term. If you decide to modify any of these attributes of your running DB Instance class before the end of the reservation term, your hourly usage rates for that DB Instance will revert to on demand hourly rates. If you later modify the running DB Instance's attributes to match those of the original reservation, or create a new DB Instance with the same attributes as your original reservation, your reserved pricing will be applied to it until the end of your reservation term.

Can I move a Reserved Instance from one Region or Availability Zone to another?

Each Reserved Instance is associated with a specific Region, which is fixed for the lifetime of the reservation and cannot be changed. Each reservation can, however, be used in any of the available AZs within the associated Region.

Are Reserved Instances available for Multi-AZ Deployments?

Yes. When you call the DescribeReservedDBInstancesOfferings API, simply look for the Multi-AZ options listed among the DB Instance configurations available for purchase. If you want to purchase a reservation for a DB Instance with synchronous replication across multiple Availability Zones, specify one of these offerings in your PurchaseReservedDBInstancesOffering call.

Are Reserved Instances available for Read Replicas?

A standard DB Instance reservation can also be applied to a Read Replica, provided the DB Instance class and Region are the same. When computing your bill, our system will automatically apply your Reservation(s), such that all eligible DB Instances are charged at the lower hourly Reserved Instance rate.

Can I cancel a reservation?

The one-time payment for Reserved Instances is not refundable. However, you can choose to terminate your DB Instance at any time, at which point you will not incur any hourly usage charges.

Can I exchange my existing Reserved Instances for the lower priced Reserved Instances that came out on March 5, 2012?

Generally, Reserved Instances are nonrefundable; however, as a special exception, if you have purchased a 1-year Reserved Instance in the past 30 days or a 3-year Reserved Instance in the past 90 days, you can exchange it for one of the new Reserved Instances. When you exchange a Reserved Instance, upfront fees will be refunded on a pro rata basis, and hourly fees for instance-hours already used will not be refunded. If you would like to exchange a Reserved Instance for one of the new ones, please contact us.