# Capacity Reservation groups You can use AWS Resource Groups to create logical collections of Capacity Reservations, called *resource groups*. A resource group is a logical grouping of AWS resources that are all in the same AWS Region. For more information about resource groups, see [What are resource groups?](https://docs.aws.amazon.com/ARG/latest/userguide/) in the *AWS Resource Groups User Guide*. You can include Capacity Reservations that you own in your account, and Capacity Reservations that are shared with you by other AWS accounts in a single resource group. You can also include Capacity Reservations that have different attributes (instance type, platform, Availability Zone, and tenancy) in a single resource group. When you create resource groups for Capacity Reservations, you can target instances to a group of Capacity Reservations instead of an individual Capacity Reservation. Instances that target a group of Capacity Reservations match with any Capacity Reservation in the group that has matching attributes (instance type, platform, Availability Zone, and tenancy) and available capacity. If the group does not have a Capacity Reservation with matching attributes and available capacity, the instances run using On-Demand capacity. If a matching Capacity Reservation is added to the targeted group at a later stage, the instance is automatically matched with and moved into its reserved capacity. To prevent unintended use of Capacity Reservations in a group, configure the Capacity Reservations in the group to accept only instances that explicitly target the capacity reservation. To do this, set **Instance eligibility** to **Only instances that specify this reservation** when creating the Capacity Reservation using the Amazon EC2 console. When using the AWS CLI, specify `--instance-match-criteria targeted` when creating the Capacity Reservation. Doing this ensures that only instances that explicitly target the group, or a Capacity Reservation in the group, can run in the group. If a Capacity Reservation in a group is canceled or expires while it has running instances, the instances are automatically moved to another Capacity Reservation in the group that has matching attributes and available capacity. If there are no remaining Capacity Reservations in the group that have matching attributes and available capacity, the instances run in On-Demand capacity. If a matching Capacity Reservation is added to the targeted group at a later stage, the instance is automatically moved into its reserved capacity. **Topics** + [Create a group](create-group.md) + [Add Capacity Reservation to group](add-to-group.md) + [Remove Capacity Reservation from group](remove-from-group.md) + [Delete group](delete-group.md) + [Using Capacity Reservation in cluster placement groups with a Capacity Reservation group](using-cpg-odcr-crg.md) # Create a Capacity Reservation group You can use the following examples to create a resource group for Capacity Reservations with the following request parameters. + `AWS::EC2::CapacityReservationPool` – Ensures that the resource group can be targeted for instance launches. + `AWS::ResourceGroups::Generic` with `allowed-resource-types` set to `AWS::EC2::CapacityReservation` – Ensures that the resource group accepts Capacity Reservations only. After you create a group, you can [add Capacity Reservations](add-to-group.md) to the group. ------ #### [ AWS CLI ] **To create a group for Capacity Reservations** Use the [create-group](https://docs.aws.amazon.com/cli/latest/reference/resource-groups/create-group.html) AWS CLI command. ``` aws resource-groups create-group \ --name MyCRGroup \ --configuration \ '{"Type": "AWS::EC2::CapacityReservationPool"}' \ '{"Type": "AWS::ResourceGroups::Generic", "Parameters": [{"Name": "allowed-resource-types", "Values": ["AWS::EC2::CapacityReservation"]}]}' ``` ------ #### [ PowerShell ] **To create a group for Capacity Reservations** Use the [New-RGGroup](https://docs.aws.amazon.com/powershell/latest/reference/items/New-RGGroup.html) cmdlet. ``` New-RGGroup ` -Name MyCRGroup ` -Configuration ` @{"Type"="AWS::EC2::CapacityReserationPool"} ` @{"Type"="AWS::ResourceGroups::Generic"; "Parameters"=@{"allowed-resource-types"=@{"Values"="AWS::EC2::CapacityReservations"}}} ``` ------ # Add a Capacity Reservation to a group If you add a Capacity Reservation that is shared with you to a group, and that Capacity Reservation is unshared, it is automatically removed from the group. ------ #### [ AWS CLI ] **To add a Capacity Reservation to a group** Use the [group-resources](https://docs.aws.amazon.com/cli/latest/reference/resource-groups/group-resources.html) command. The following example adds two Capacity Reservations to the specified group. ``` aws resource-groups group-resources \ --group MyCRGroup \ --resource-arns \ arn:aws:ec2:sa-east-1:123456789012:capacity-reservation/cr-1234567890abcdef1 \ arn:aws:ec2:sa-east-1:123456789012:capacity-reservation/cr-54321abcdef567890 ``` ------ #### [ PowerShell ] **To add a Capacity Reservation to a group** Use the [Add-RGResource](https://docs.aws.amazon.com/powershell/latest/reference/items/Add-RGResource.html) cmdlet. The following example adds two Capacity Reservations to the specified group. ``` Add-RGResource ` -Group MyCRGroup ` -ResourceArn ` "arn:aws:ec2:sa-east-1:123456789012:capacity-reservation/cr-1234567890abcdef1", ` "arn:aws:ec2:sa-east-1:123456789012:capacity-reservation/cr-54321abcdef567890" ``` ------ # Remove a Capacity Reservation from a group You can use the following examples to remove a Capacity Reservation from a group. ------ #### [ AWS CLI ] **To remove a Capacity Reservation from a group** Use the [ungroup-resources](https://docs.aws.amazon.com/cli/latest/reference/resource-groups/ungroup-resources.html) command. The following example removes two Capacity Reservations from the specified group. ``` aws resource-groups ungroup-resources \ --group MyCRGroup \ --resource-arns \ arn:aws:ec2:sa-east-1:123456789012:capacity-reservation/cr-0e154d26a16094dd \ arn:aws:ec2:sa-east-1:123456789012:capacity-reservation/cr-54321abcdef567890 ``` ------ #### [ PowerShell ] **To remove a Capacity Reservation from a group** Use the [Remove-RGResource](https://docs.aws.amazon.com/powershell/latest/reference/items/Remove-RGResource.html) cmdlet. The following example removes two Capacity Reservations from the specified group. ``` Remove-RGResource ` -Group MyCRGroup ` -ResourceArn ` "arn:aws:ec2:sa-east-1:123456789012:capacity-reservation/cr-0e154d26a16094dd", ` "arn:aws:ec2:sa-east-1:123456789012:capacity-reservation/cr-54321abcdef567890" ``` ------ # Delete a Capacity Reservation group You can use the following examples to delete a Capacity Reservation group. ------ #### [ AWS CLI ] **To delete a group** Use the [delete-group](https://docs.aws.amazon.com/cli/latest/reference/resource-groups/delete-group.html) command. ``` aws resource-groups delete-group --group MyCRGroup ``` ------ #### [ PowerShell ] **To delete a group** Use the [Remove-RGGroup](https://docs.aws.amazon.com/powershell/latest/reference/items/Remove-RGGroup.html) cmdlet. ``` Remove-RGGroup -GroupName MyCRGroup ``` ------ # Using Capacity Reservation in cluster placement groups with a Capacity Reservation group Amazon EC2 provides different launch methods for you to use Capacity Reservations in a cluster placement group with a Capacity Reservation group. You can choose one of the following methods to target a Capacity Reservation group based on your workload requirements: + *Specifying the ARN of the cluster placement group and Capacity Reservation group* – This will use any available Capacity Reservation with matching attributes and available capacity in the selected Capacity Reservation group. If the selected group does not have a Capacity Reservation with matching attributes and available capacity, the instances launch into On-Demand capacity. **Note** When you launch instances using this method, the instances are placed in the specified cluster placement group. + *Specifying only a Capacity Reservation group* – This will use all available capacity within the Capacity Reservation group by specifying only the Capacity Reservation group. While launching instances, capacity is used in the following order: + Capacity Reservations not associated with any cluster placement group. + Capacity Reservation in any cluster placement group within the Capacity Reservation group. + If the group does not have a Capacity Reservation with matching attributes and available capacity, the instances run using On-Demand capacity and they are not placed in any cluster placement group. **Note** When you launch instances by specifying only a Capacity Reservation group, the instances are launched into the Capacity Reservations that are created in the cluster placement group, but the instances are not directly attached to the cluster placement group.