Share resource-based CUDs across projects

This document explains how you can share resource-based committed use discounts (CUDs) across projects in your Cloud Billing account.

CUD sharing lets you share resource-based CUDs from a single commitment to cover eligible resource usage across all projects within the same Cloud Billing account. This approach lets you pool resource-based CUDs across all projects within the same Cloud Billing account. By enabling CUD sharing, you maximize your savings and reduce the overhead of managing discounts on a per-project basis.

How CUD sharing works

By default, resource-based CUDs apply at the project level and you receive the applicable CUDs only for the project in which you purchase the commitment. However, Compute Engine lets you share discounts for resource-based commitments across multiple projects that share the same Cloud Billing account.

You enable or disable CUD sharing by changing the CUD scope in your Cloud Billing. Resource-based CUDs have two scope options:

• Project: Resource-based CUDs from a commitment are limited to the project in which the commitment was purchased. This is the default scope.
• Billing account: Resource-based CUDs from all commitments in the Cloud Billing are shared across all linked projects.

To enable CUD sharing, you must change the CUD scope for the Cloud Billing account from Projectto Billing account. You can disable CUD sharing by changing your CUD scope back to Project. You can change the CUD scope at any time to enable or disable CUD sharing. After you change your CUD scope, the time it takes for the change to take effect depends on your selection:

• Billing account (enabling CUD sharing): The change takes effect at 12:00 AM US and Canadian Pacific Time the following day.
• Project (disabling CUD sharing): The change takes effect within a few moments.

For example, you purchase two resource-based commitments for 80 cores each (a total of 160 cores) and you run 200 cores during the month across different projects in your Cloud Billing account. If you've enabled CUD sharing for your Cloud Billing account, then you receive the applicable resource-based CUDs for 160 of those 200 cores that are used across the projects in that Cloud Billing account. The additional 40 cores are billed at on-demand, non-committed use rates. After you purchase your commitments, you're billed for your committed resources monthly, throughout the commitment time period, even if you don't use the resources. See Understand CUD sharing for cost-saving utilization recommendations.

Attribution for shared CUDs

Attribution refers to how Google Cloud allocates your CUDs across projects after you enable CUD sharing. These allocations are reflected in Cloud Billing cost management interfaces, such as the usage cost export or the Google Cloud console .

You can choose one of the following types of attribution:

• Proportional attribution . Your CUDs are shared across projects based on each project's proportion of the total eligible usage. This is the default attribution type.
• Prioritized attribution . You specify the order in which projects receive CUDs.

Proportionally attributed commitments are applied to usage from projects based on each project's share of the total eligible usage. For example, suppose project A consumes US$75 worth of usage and project B consumes US$25 worth of usage, then project A gets covered by up to 75% of the available CUDs and project B gets covered by up to 25%.

Prioritized attribution applies your commitments to usage based on the distribution settings that you specify. You can choose the projects, along with the amount of usage within each project, that get covered by the commitments. After your prioritized commitments are applied to eligible usage, any remaining unprioritized commitments are applied proportionally to the eligible usage in your remaining projects. The total amount of the allotments cannot exceed the commitment amount purchased.

You can update attribution preferences anytime during the commitment's lifetime. However, any attribution preferences that you configure are applied only after you enable CUD sharing. To choose proportional or prioritized attribution for your Compute Engine commitments, see choose attribution for resource-based commitments .

Limitations

• If you have a shared reservation in a project and want usage from the shared projects to be eligible for shared CUDs from your commitment's Cloud Billing account, then you must share your reservation only with projects that are linked to the same Cloud Billing account. Otherwise, usage from those projects won't be eligible for shared CUDs and you might be charged the on-demand rates.

• After you enable CUD sharing for a Cloud Billing account, if any portion of a commitment remains unutilized within a given month, then the commitment fee for that remaining portion gets charged to the project where you purchased that commitment.

Check whether CUD sharing is enabled

To check if CUD sharing is enabled for your Cloud Billing account, complete the following steps:

1. In the Google Cloud console, go to the CUD analysispage.

   Go to CUD analysis

2. At the prompt, choose the Cloud Billing account that you want to view. The Committed use discount analysispage appears.

3. In the Analyzemenu, select Resource-based CUDs. The settings CUD scope & settingsbutton appears in the toolbar.

4. Click settings CUD scope & settings.

5. In the Resource-based CUDs scopesection of the CUD scope & settingspage that appears, you can review your current CUD scope configuration. The CUD scope can be one of the following:

   • Project: This selection indicates that CUD sharing isn't enabled for resource-based commitments. CUDs from a commitment apply to eligible usage only in the project where the commitment was purchased.

   • Billing account: This selection indicates that CUD sharing is enabled for resource-based commitments. CUDs from any resource-based commitment in the current Cloud Billing account are shared and applied to eligible usage across all projects that are associated with the Cloud Billing account.

Enable CUD sharing

To share the CUDs from your resource-based commitments across eligible usage in all projects linked to your Cloud Billing account, enable CUD sharing by changing the CUD scope in the Google Cloud console. After you change your CUD scope to Billing account, CUD sharing is enabled on all of the current and future projects associated with the Cloud Billing account.

CUD sharing works in conjunction with your attribution configuration. Unless you configure your attribution preferences first, when you enable CUD sharing, it defaults to using proportional attribution for your Compute Engine resource-based commitments. If you want to configure your attribution configuration before you enable CUD sharing , see choose attribution for resource-based commitments for more information and how to enable each type of attribution.

Permissions required for this task

To perform this task, you must have the following permissions :

You need specific permissions on the Cloud Billing account to access Cloud Billing information. To update the CUD scope and enable CUD sharing, you need a role that includes the following permission on the Cloud Billing account:

• billing.subscriptions.update on the Cloud Billing account

To gain this permission using a predefined role, ask your billing administrator to grant you the Billing Account Administrator role on the Cloud Billing account.

To enable CUD sharing, complete the following steps:

1. In the Google Cloud console, go to the CUD analysispage.

   Go to CUD analysis

2. At the prompt, choose the Cloud Billing account for which you want to enable CUD sharing.

3. In the toolbar of the CUD analysispage, click settings CUD scope & settings. The CUD scope & settingspage appears.

4. In the Resource-based CUDs scopesection, select Billing account.

5. To save your updated CUD scope and enable CUD sharing, click Save.

   After you save the changes, the updated CUD scope takes effect at 12:00 AM US and Canadian Pacific Time the following day. You can verify that the CUD scope is correctly set .

Disable CUD sharing

To disable CUD sharing, complete the following steps:

1. In the Google Cloud console, go to the CUD analysispage.

   Go to CUD analysis

2. At the prompt, choose the Cloud Billing account for which you want to disable CUD sharing.

3. In the toolbar of the CUD analysispage, click settings CUD scope & settings. The CUD scope & settingspage appears.

4. In the Resource-based CUDs scopesection, select Project.

5. To save your updated CUD scope and disable CUD sharing, click Save.

   After you save the changes, the updated CUD scope takes effect within a few moments. You can verify that the CUD scope is correctly set .

What's next

• Learn about attribution for resource-based commitments .
• Learn how to analyze the effectiveness of your CUDs .