Microsoft Fabric Reservations: Understanding What They Are and How to Create Them

[jbarry15]

What are Reservations?

Reservations, often referred to as "reserved instances" or "RIs," are a way for customers to save money by committing to a specific Azure product for a set duration, typically one or three years. This commitment provides a discount on the resources used within their Azure subscriptions. Customers can choose to pay for these reservations either upfront or monthly, with no difference in cost or benefit between the payment options. Additionally, longer commitments offer greater discounts, potentially reducing resource costs by up to 72% compared to pay-as-you-go pricing.

Why purchase a reservation?

The short answer is for consistent usage of a product which an organization is planning to use for one of the commitment durations to reduce costs on Azure spend. This can help lead to predictable spending and financial planning compared to a pay-as-you-go rate.

How are the discounts applied?

Once purchased in the Azure Portal, the discount will be applied to the “resource usage” that matches the attributes selected when buying the reservation. This can include the SKU, region and an extremely important attribute: scope. The reservation scope can be applied to different levels, which include Single Resource group scope, Single Subscription scope, Shared scope, and Management Group scope. So, what do all these scopes mean?

• Single resource group scope - Applies the reservation discount to the matching resources in the selected resource group only.
• Single subscription scope - Applies the reservation discount to the matching resources in the selected subscription.
• Shared scope - Applies the reservation discount to matching resources in eligible subscriptions that are in the billing context. If a subscription is moved to different billing context, the benefit no longer applies to the subscription. It continues to apply to other subscriptions in the billing context.
• For enterprise customers, the billing context is the EA enrollment. The reservation shared scope would include multiple Microsoft Entra tenants in an enrollment.
• For Microsoft Customer Agreement customers, the billing scope is the billing profile.
• For pay-as-you-go customers, the shared scope is all pay-as-you-go subscriptions created by the account administrator.
• Management group - Applies the reservation discount to the matching resource in the list of subscriptions that are a part of both the management group and billing scope. The management group scope applies to all subscriptions throughout the entire management group hierarchy. To buy a reservation for a management group, you must have at least read permission on the management group and be a reservation owner or reservation purchaser on the billing subscription.

How does all of this apply to Fabric Capacities?

You can save money with Fabric Capacity reservations by committing to a reservation for usage duration of one year currently. The reservation does not cover storage or networking charges that may be associated with Microsoft Fabric usage, only the Fabric Capacity. When the Fabric Capacity usage matches the reservation attributes, you are not charged at the pay-as-you-go price.

When purchasing a Fabric Capacity reservation, it’s worth noting that the reservation “units” apply to the quantity of capacity units (CUs). This means it’s extremely important to understand the total CUs that you plan to consume. For example, assume that your total CUs are 128 and you are interested in purchasing a reservation for all of it. Since your total CU usage has been identified as 128, you should purchase a 128 CU reservation quantity.  

Buy a Microsoft Fabric Capacity Reservation:

To purchase a reservation, you’ll need to the appropriate permissions on an Azure Subscription, such as the owner or reservation purchaser in the Microsoft Azure Portal: https://portal.azure.com/. Once signed in with the appropriate permission, navigate to All Service -> Reservations in the azure portal where you’ll see Microsoft Fabric listed as shown in the image below:

Then we want to select Microsoft Fabric and click “Next: Review + buy”. This will bring up a purchasing window as seen in the image below. You’ll want to select a subscription from the list, which will be used to pay for the reservations for the Fabric Capacity. For further information on qualifying subscription types, please refer to this documentation.

Now that you’ve selected the appropriate subscription, it’s time to scope, select a region and decide the billing frequency.

The scope is important because it defines the intent of which Fabric Capacities will receive the reservation discount. For example, if my business unit is part of a larger organization subscription but isolated to a resource group, then I would want the scope to be at a resource group level to ensure the Fabric Capacity reservations are being applied to my business unit Fabric Capacities. Also, pay attention to the region as this will affect the coverage of the reservation.

I’ve now selected my scope, region and billing frequency as shown in the image below and we’ll want to select “Add to Cart”.

Once you’ve added the reservation to the cart, there are a few key items to be aware of.

First, your reservation will now have a line item. At this point, you’ll have the ability to auto-renew, change the billing frequency one last time and update the quantity.

Second, make sure to choose the right size quantity based on the total CUs that you consume as they are made in one CU increments. As mentioned earlier, assume the total consumption of Fabric Capacity is F128 (includes 128 CUs). The reservation you’ll need to purchase for all of it should be 128 CUs of reservation quantity.

At this point, the reservation will be ready to review and buy as shown in the image below:

Since everything is correct on the reservation, the final step is “Buy now” and that’s it!

What’s next?

Once the reservations have been made, I’ve had some customers ask about changing, canceling or getting a refund for a reservation. Further information can be found here on the process for each scenario.

I would also like to mention one misconception that some customers have raised questions about. The reservation process is separate from creating the Fabric Capacity in your Azure Subscription. For guidance on creating a Fabric Capacity in the Azure portal, please see this reference.

To wrap everything up, I hope this article was helpful as an overview of the reservation process: creating one, scoping it and understanding the importance of identifying the right capacity unit size!

References:

Save costs with Microsoft Fabric Capacity reservations - Microsoft Cost Management | Microsoft Learn

Buy an Azure reservation - Microsoft Cost Management | Microsoft Learn

Buy a Microsoft Fabric subscription - Microsoft Fabric | Microsoft Learn