(ec2): support throughput option in EBS volume

For EBS volumes with volume type GP3, the throughput in MiB/s can be configured. This is currently not supported in CDK.

Workaround: use escape hatches

Use Case

Set custom value for throughput, impacts performance and pricing.

Proposed Solution

The property is available in ebs volume and launchtemplate blockdevicemaping. It should be supported in both constructs.

Check if the property can be added to EbsDeviceOptionsBase or only to one of its subclasses (EbsDeviceOptions and EbsDeviceSnapshotOptions). Nothing specific is mentioned in the documentation.

Display a warning if throughput is defined for a volume type that does not support specifying a throughput. Display an error if a throughput value is specified that is not supported.

Other

Originally mentioned as comment in issue #12020.

• 👋 I may be able to implement this feature request
• ⚠️ This feature might incur a breaking change

---

This is a 🚀 Feature Request

[csumpter]

Hey, i just stumbled upon this issue while looking for a way of defining the throughput of GP3 volumes. I understand from this PR that it’s not currently supported via the aws_ec2.BlockDeviceVolume.ebs function.

Until this feature is merged, is there any workaround for defining it?

You can do something like:

    interface ExtendedEbsDeviceOptions extends autoscaling.EbsDeviceOptions {
      throughput: number;
    }

    const asg = new autoscaling.AutoScalingGroup(this, "example", {
      blockDevices: [{
        deviceName: "/dev/sda1",
        volume: autoscaling.BlockDeviceVolume.ebs(1, {
         ...
          volumeType: autoscaling.EbsDeviceVolumeType.GP3,
          throughput: 125,
        } as ExtendedEbsDeviceOptions),
      }],
      ...
    })

This extends the type to include throughput where it will becomes rendered as Throughput by the cdk as it transforms that property.

There are other ways to get the throughput property rendered out with the resource but this is probably the easiest.

If you need to do get the compatibility for an ec2 volume you would do something like:

    interface Ec2VolumeExtended extends ec2.VolumeProps {
      throughput: number;
    }
    const volume = new ec2.Volume(this, "volume", {
      volumeType: ec2.EbsDeviceVolumeType.GP3,
      throughput: 125,
      ...
    } as Ec2VolumeExtended)

[tmokmss]

I also stumbled on this today for launch templates. Here’s the workaround:

const launchTemplate = new ec2.LaunchTemplate(this, 'LaunchTemplate', {
  // omitting other required properties
  blockDevices: [
    {
      deviceName: '/dev/xvda',
      volume: ec2.BlockDeviceVolume.ebs(100, {
        volumeType: ec2.EbsDeviceVolumeType.GP3,
      }),
    },
  ],
});
(launchTemplate.node.defaultChild as CfnResource).addPropertyOverride("LaunchTemplateData.BlockDeviceMappings.0.Ebs.Throughput", 200)

I’m not sure why LaunchTemplate ebs supports throughput (doc), whereas instance ebs not (doc).

edit) I found the corresponding issue on CFn repo: https://github.com/aws-cloudformation/cloudformation-coverage-roadmap/issues/824