Tutorial: Configure your EC2 Fleet to launch instances into multiple Capacity Reservation types using a Capacity Reservation Resource Group

This tutorial walks you through the steps to configure an EC2 Fleet that launches instances across multiple Capacity Reservation types – On-Demand Capacity Reservations (ODCRs), Capacity Blocks for ML, and interruptible Capacity Reservations – using a single Capacity Reservation Resource Group.

You will learn how to create a Capacity Reservation Resource Group that contains different Capacity Reservation types, configure your EC2 Fleet to prioritize the Capacity Reservation types in a specific order, and optionally fall back to On-Demand capacity when reserved capacity is insufficient to meet your target.

Considerations

This tutorial assumes that you already have the following Capacity Reservations in your account:

Verify permissions

Before creating an EC2 Fleet, verify that you have an IAM role with the required permissions. For more information, see EC2 Fleet prerequisites.

Step 1: Create a Capacity Reservation Resource Group

Create a Capacity Reservation Resource Group to hold the Capacity Reservations that your EC2 Fleet targets. Configure the group so that it accepts Capacity Reservations of any instance type and Capacity Reservation type, which allows the group to hold a mix of Capacity Reservation types. For step-by-step instructions, see Capacity Reservation groups.

Step 2: Add Capacity Reservations to the group

Add your Capacity Reservations to the Capacity Reservation Resource Group. You can add any combination of ODCRs, Capacity Blocks for ML, interruptible Capacity Reservations, and UltraServer Capacity Blocks. For this tutorial, add the four Capacity Reservations listed at the beginning of this tutorial. For step-by-step instructions, see Capacity Reservation groups.

Step 3: Create a launch template

Use the create-launch-template command to create a launch template that targets the Capacity Reservation Resource Group. When you use ReservedCapacityOptions in your EC2 Fleet configuration, you do not need to set a MarketType in the launch template – EC2 Fleet sets this automatically for each Capacity Reservation type.

aws ec2 create-launch-template \
    --launch-template-name my-cr-resource-group-template \
    --launch-template-data \
        '{"ImageId": "ami-0123456789example",
          "CapacityReservationSpecification":
            {"CapacityReservationTarget":
                {"CapacityReservationResourceGroupArn": "arn:aws:resource-groups:us-east-1:123456789012:group/my-cr-resource-group"}
            }
        }'

Step 4: Create an EC2 Fleet

Create an EC2 Fleet that targets multiple Capacity Reservation types in your Capacity Reservation Resource Group. The key configuration is ReservedCapacityOptions, which specifies the following:

Create a file named config.json with the following content. In the following example, replace the resource identifiers with your own resource identifiers.

{
    "LaunchTemplateConfigs": [
        {
            "LaunchTemplateSpecification": {
                "LaunchTemplateName": "my-cr-resource-group-template",
                "Version": "1"
            },
            "Overrides": [
                {
                    "InstanceType": "p5.48xlarge",
                    "AvailabilityZone": "us-east-1a",
                    "Priority": 1
                },
                {
                    "InstanceType": "p4d.48xlarge",
                    "AvailabilityZone": "us-east-1b",
                    "Priority": 2
                }
            ]
        }
    ],
    "TargetCapacitySpecification": {
        "TotalTargetCapacity": 100,
        "DefaultTargetCapacityType": "reserved-capacity"
    },
    "ReservedCapacityOptions": {
        "ReservationTypes": ["on-demand-capacity-reservation", "capacity-block", "interruptible-capacity-reservation"],
        "ReservedCapacityFallbackOptions": {
            "MarketTypes": ["on-demand"]
        },
        "AllocationStrategy": "prioritized"
    },
    "Type": "instant"
}

Use the create-fleet command to launch the fleet:

aws ec2 create-fleet --cli-input-json file://config.json

For more information, see Create an EC2 Fleet.

How EC2 Fleet resolves Capacity Reservations

Based on the preceding configuration, EC2 Fleet attempts to launch instances in the following order:

(Optional) Step 5: Verify instance properties

Use the describe-instances command to verify which Capacity Reservation type each instance consumed. Instances launched by the fleet display the following properties.

You can filter instances by Capacity Reservation Resource Group using the following command:

aws ec2 describe-instances \
    --filters "Name=capacity-reservation-specification.capacity-reservation-target.capacity-reservation-resource-group-arn,Values=arn:aws:resource-groups:us-east-1:123456789012:group/my-cr-resource-group"

Clean up

To stop incurring charges, terminate the instances when they are no longer needed. Note that instances launched into Capacity Blocks are automatically terminated when the Capacity Block reservation ends. Instances launched into interruptible Capacity Reservations are automatically terminated if the capacity owner reclaims the capacity.

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