Amazon EC2 placement groups can now be shared across multiple AWS accounts

You can now share Amazon EC2 placement groups across multiple AWS accounts using AWS Resource Access Manager (RAM). When a placement group is shared, instances launched by one AWS account can utilize a placement group created by another account. RAM helps you securely share your resources across AWS accounts, within your organization or organizational units (OUs) in AWS Organizations, and with IAM roles and IAM users for supported resource types.

Placement groups influence the placement of interdependent EC2 instances on the underlying hardware. You can select a placement group strategy that best meets the needs of your workload, whether that be low network latency or increased fault tolerance. With placement group sharing, the benefits offered by placement groups are no longer limited to the boundaries of a single account. For example, if you have workloads under different accounts and want low latency between these workloads, then you can use placement group sharing (with cluster placement strategy) to place the instances across accounts closer to each other.

To share a placement group, create a resource share through AWS RAM. Then, add the resources (placement groups) to the resource share and specify the target accounts that you wish to share the resources with. You can see placement groups that have been shared with your account in the EC2 console’s placement groups pane or by using the describe-placement-groups API. To use a shared placement group, specify the placement group Id while launching your instances.

This feature is now available in all commercial AWS Regions for free. You can create and manage placement groups through the AWS Management Console, AWS SDKs or AWS Command Line Interface (CLI). To learn more about EC2 placement groups, visit the Linux or Windows user guide for placement groups.