What happens to a 3-year reservation when changing the pricing tier or plan?

Hi @kim

The key point is that an Azure Managed Redis reservation is a billing benefit rather than a reservation tied permanently to a specific cache instance.

If the Azure Managed Redis configuration is changed, the three-year reservation itself continues to exist. However, the reservation benefit is applied only to eligible usage that matches the attributes of the reservation purchased.

Therefore, before changing from B10 to B20/B5, or moving from Balanced to Compute Optimized or Memory Optimized, you should verify whether the target configuration matches the existing reservation. If it does not match, the existing reservation benefit will no longer be applied to that usage, and the reservation should be exchanged for one that matches the new configuration to avoid unused reservation capacity.

You can review and exchange reservations through the Azure portal as needed.

For more details, please refer to:

https://learn.microsoft.com/en-us/azure/redis/reserved-pricing

https://learn.microsoft.com/azure/cost-management-billing/reservations/exchange-and-refund-azure-reservations

Hope this clarifies the reservation behavior.

Hi,

When you change to different Managed Redis tier, you will need to exchange your existing reservation for a new one that matches the attributes of the new tier.

For example, if you purchase 3-year reservation for B10 tier in East US Scope: Shared, and you create Azure Managed Redis B10 in East US. At this point the reservation will apply the discount because the Managed Redis instance attributes match the reservation.

Later you change it to B20 tier. At this point the reservation WILL NOT apply since there is no Managed Redis instance with matching attributes. This is why you need to exchange the reservation for B20 tier, otherwise the reservation would be wasted, since reservations are "use-it-or-lose it".

Please let me know if the above is unclear and/or if you have questions. The article below details how reservations are applied:

How the reservation discount is applied to Azure Cache for Redis

https://learn.microsoft.com/en-us/azure/cost-management-billing/reservations/understand-azure-cache-for-redis-reservation-charges

Below article provides general information on Azure Managed Redis reservations:

Use reservations to prepay for Azure Managed Redis compute resources

https://learn.microsoft.com/en-us/azure/redis/reserved-pricing

With the above in mind, answers to your questions:

Q1: Does the existing three-year reservation remain active after the plan change?

A: The reservation will still exist, but will not apply to the new plan since it doesn't match

Q2: Is the reservation discount automatically applied to the new plan?

A: No, the discount will not apply to the new plan

Q3: When changing to a different performance tier, is it necessary to exchange or cancel the existing reservation and purchase a new one?

A: Yes, it is necessary to exchange the existing reservation for a new one that matches the new tier, otherwise the reservation will be wasted

Please click Accept Answer and upvote if the above was helpful.

Thanks.

-TP