This document explains how you can share resource-based committed use discounts (CUDs) across your Cloud Billing account.
By default, resource-based CUDs from a commitment are limited to the project in which that commitment was created. You can change the commitment scope for your Cloud Billing and share these CUDs across projects that are linked to that Cloud Billing.
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. If you move the project for which you purchased your commitment to a different Cloud Billing account, then you continue to receive the applicable CUDs for that project under the new Cloud Billing account.
However, Compute Engine lets you share discounts for resource-based commitments across multiple projects that share the same Cloud Billing account. Sharing your resource-based CUDs for commitments across all your projects reduces the overhead of managing discounts on a per-project basis, and maximizes your savings by pooling all your discounts across your projects' resource usage.
If you have multiple projects that share the same Cloud Billing account, then you can enable CUD sharing so that all of your projects within that Cloud Billing account share CUDs from all of your resource-based commitments.
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 discount sharing for cost-saving utilization recommendations.
CUDs are subject to Google Cloud commitment-based pricing and billing. By purchasing a commitment, you agree to these terms.
Use attribution to allocate discounts
Attribution refers to how your committed use discounts are allocated across your projects. These allocations are reflected in Cloud Billing cost management interfaces, such as the usage cost export or the Google Cloud console.
Attribution applies only when discount sharing is enabled. You can choose the type of attribution you want to use before you turn on discount sharing, and then activate the attribution configuration when you enable discount sharing.
Compute Engine commitments use proportional attribution by default. Proportional attribution commitments are applied to the projects according to the amount of the total eligible usage consumed by each project. For example, if project A consumed $75 worth of usage and project B consumed $25, project A would be covered by up to 75% of available credit and project B would be covered by up to 25%.
Alternatively, you can choose prioritized attribution for your Compute Engine commitments based on the usage you specify. 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.
To choose proportional or prioritized attribution for your Compute Engine commitments, see choose attribution for resource-based commitments.
Restrictions
- If you have a shared reservation and also enabled CUD sharing for your commitment's Cloud Billing account, then, to make sure that usage from your consumed shared reservation is eligible for resource-based CUDs, you must share your reservation only with projects that are linked to the commitment's Cloud Billing account. Doing so helps you avoid being charged at on-demand rates for usage that is eligible for CUDs.
- When you enable CUD sharing for a Cloud Billing account, if any portion of a commitment is unutilized, then the remaining commitment charge remains in the project where you purchased that commitment.
Enable CUD sharing for resource-based commitments
By default, resource-based CUDs are applied to the project where you purchased your resource-based commitments and are project-scoped discounts. If you move the project for which you purchased your commitments to a different Cloud Billing account, then you continue to receive the applicable CUDs for that project under the new Cloud Billing account.
To share the CUDs from your resource-based commitments across eligible usage in all projects linked to your Cloud Billing account, enable CUD sharing from the Google Cloud console.
When you enable CUD sharing, you change the commitment scope from Project to Billing account.
CUD sharing works in conjunction with your attribution configuration. You can choose to use proportional attribution or prioritized attribution.
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.
To enable CUD sharing, complete the following steps:
In the Google Cloud console, go to the CUD analysis page.
At the prompt, choose the Cloud Billing account that you want to view.
On the CUD analysis page, select All resource-based CUDs from the Analyze drop-down.
In the Utilization of CUDs summary card, locate the CUD credits scope.
- Project scope indicates that CUD sharing isn't enabled for resource-based commitments. Project-scoped CUDs only apply to eligible usage in the project in which the commitments are purchased.
- Billing account scope indicates that CUD sharing is enabled for resource-based commitments. Billing-account-scoped commitments share their CUDs across all eligible usage in all projects associated with the Cloud Billing account.
To change the commitment scope setting, select Edit.
If the current scope is Project, in the text entry box, type Enable to enable CUD sharing across the Cloud Billing account, then click Enable Billing Account Scope to save your changes.
If the current scope is Billing account, then CUD sharing is already enabled. To disable CUD sharing and revert to Project-scoped commitments, click Contact support.
You only need to enable CUD sharing on one project-scoped resource-based commitment to affect the scope of all resource-based commitments in the same Cloud Billing account. When you enable CUD sharing, your commitment scope changes as follows:
- All of your current and active resource-based CUDs in all of the projects under the same Cloud Billing account, including those you previously purchased and new ones you purchase in the future, are shared across your Cloud Billing account.
- When you change your commitment scope configuration, such as creating a new project linked to the Cloud Billing account, or linking an existing project to the Cloud Billing account, the change takes effect on the following day at 12 AM (midnight) US and Canadian Pacific Time (UTC-8 or UTC-7).
- If you move the project that had the original commitment to a new Cloud Billing account, your CUD sharing settings change. For information on the effects of changing the Cloud Billing account for a project, see Change the Cloud Billing account linked to a project.
To get a better understanding of how CUDs impact and appear on your bill, see Understand your bill with committed use discounts.