Use Capacity Reservations in your Auto Scaling group
With Amazon EC2 Auto Scaling and Amazon EC2 Capacity Reservations, you can launch instances from your Auto Scaling group into reserved compute capacity. This page describes the Capacity Reservation types that Auto Scaling supports and helps you choose the approach that fits your workload.
What are Capacity Reservations?
A Capacity Reservation reserves Amazon EC2 compute capacity in a specific Availability Zone, so that capacity is available when your Auto Scaling group needs to launch instances. Amazon EC2 offers several types of Capacity Reservations that fit different workload patterns. For more information, see Capacity Reservations in the Amazon EC2 User Guide.
Capacity Reservation types supported
Auto Scaling supports the following Amazon EC2 Capacity Reservation types.
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On-Demand Capacity Reservations – Reserve compute capacity in a specific Availability Zone with no term commitment. For more information, see Capacity Reservations in the Amazon EC2 User Guide.
How to use Capacity Reservations with your Auto Scaling group
Auto Scaling supports the following ways to consume Capacity Reservations. Choose based on your workload and the types of reservations you use.
| If you want to... | Use | Learn more |
|---|---|---|
| Consume On-Demand Capacity Reservations from your Auto Scaling group | A Capacity Reservation preference and target on your Auto Scaling group | Target Capacity Reservations from your Auto Scaling group |
Prerequisites
Before you can use Capacity Reservations in your Auto Scaling group, you must create the reservations that you want to use. Depending on the reservation type, see one of the following in the Amazon EC2 User Guide:
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Create a Capacity Reservation – for On-Demand Capacity Reservations
If you intend to use multiple Capacity Reservations with one Auto Scaling group, you can also create a Capacity Reservation Resource Group. For more information, see Capacity Reservation Resource Groups in the Amazon EC2 User Guide.