Azure Capacity Reservation Sharing #azure

Key Concepts

• Capacity Reservation Sharing
• Provider Subscription
• Consumer Subscriptions
• Service Level Agreement (SLA)
• Workloads (Dev/Test, Critical)
• Deprovisioning
• Scaling

Capacity Reservation Sharing Explained

Capacity Reservation Sharing is a new feature that enhances the functionality of Capacity Reservations. Previously, a Capacity Reservation was tied to the specific subscription in which it was created. This meant that the reserved capacity could only be utilized by workloads within that single subscription.

New Functionality: Provider and Consumer Subscriptions

With the introduction of Capacity Reservation Sharing, the subscription that initially creates the Capacity Reservation now acts as a provider subscription. This provider subscription, along with up to 100 consumer subscriptions, can now share and utilize the reserved capacity. This creates a capacity reservation group.

Benefits and Use Cases

This sharing capability unlocks several new scenarios and benefits:

• Optimized Resource Utilization (Sunny Day Scenarios): In normal operating conditions, lower-priority workloads such as development and testing environments, or other less critical applications, can consume the reserved capacity from these consumer subscriptions. This prevents the reserved capacity from being idle and incurring unnecessary costs. The Capacity Reservation still provides an SLA-backed guarantee for the capacity, ensuring it's available when needed.
• Guaranteed Capacity for Critical Workloads (Rainy Day Scenarios): In situations requiring a sudden surge in capacity (e.g., unexpected traffic spikes, critical operational needs), the lower-priority workloads in the consumer subscriptions can be deprovisioned. This frees up the reserved capacity, which can then be immediately utilized by more critical workloads. These critical workloads can reside either in the provider subscription or in any of the other consumer subscriptions within the group. This ensures that essential services have guaranteed access to the necessary compute resources without delay.
• Cost Efficiency: The primary advantage is the ability to ensure capacity is available when needed for critical workloads without continuously paying for that capacity when it's not actively being used by those critical workloads. Lower-priority workloads can utilize the reservation, effectively subsidizing its cost.

Technical Details and Limitations

• A single provider subscription can be associated with up to 100 consumer subscriptions.
• The Capacity Reservation itself is created in the provider subscription.
• The SLA-backed guarantee remains in effect for the reserved capacity.

Conclusion

Capacity Reservation Sharing significantly improves the flexibility and cost-effectiveness of managing reserved compute capacity. By allowing a provider subscription to share its reserved capacity with up to 100 consumer subscriptions, organizations can optimize resource utilization during normal operations while ensuring guaranteed availability for critical workloads during peak demand or unexpected events. This feature addresses the previous limitation of capacity being locked to a single subscription, enabling more dynamic and efficient resource allocation.