Resource Assurance is a service that guarantees the provision of Elastic Compute Service (ECS) resources as your needs change. It allows you to quantify the amount of available resources, reserve resources, plan private pools, and improve your experience when you query, reserve, purchase, and use resources. This topic describes the billing methods of resource assurances and examples of how resource assurances are billed.

Billing methods

You can purchase elasticity assurances or capacity reservations (including immediate capacity reservations, capacity reservations with Savings Plan, and capacity reservations for subscription resources) to reserve resources in different scenarios. After an elasticity assurance or capacity reservation is purchased, Alibaba Cloud reserves resources that match the specified attributes of the elasticity assurance or capacity reservation in a private pool. For more information, see Overview.

The following table describes the billing methods for different types of resource assurances.
Billable item Description
Elasticity assurance Purchased elasticity assurances cannot be released manually. When you use an elasticity assurance, you must pay the following fees:
  • Assurance fee generated when you purchase the elasticity assurance. During the term of the elasticity assurance, you can use the reserved capacity in the associated private pool to create pay-as-you-go instances whenever you want.
  • Hourly fees for pay-as-you-go instances that were created from the reserved capacity of the elasticity assurance.
    Note If you have purchased applicable savings plans or regional reserved instances, you can apply them to the pay-as-you-go instances.

For more information, see Overview of Elasticity Assurance.

Immediate capacity reservation When an immediate capacity reservation is purchased to reserve capacity for a specific instance type, the capacity reservation begins immediately to be billed at the pay-as-you-go price of the instance type. Billing continues as long as the capacity reservation is present in your account, regardless of whether the capacity reservation is actually used to create instances. You can manually release a capacity reservation or wait for it to be automatically released on expiration.
Note
  • Before a capacity reservation is used to create pay-as-you-go instances, you are charged only for the specified instance type. After a capacity reservation is used to create pay-as-you-go instances, you are charged based on the configurations of the instances including the instance type, disks, and public bandwidth.
  • The unused reserved capacity of a capacity reservation can be used to cover the charges for instance computing resources.

For more information, see Overview of Immediate Capacity Reservation.

Examples

The following table describes examples of how resource assurances are billed. The unit prices of ECS instances and assurance fees are for reference only. The actual prices displayed on the Pricing tab of the ECS product page prevail.
Billable item Scenario Billing
Elasticity assurance Assume that an enterprise user purchased an elasticity assurance for one ECS instance and created an ECS instance from the reserved capacity for a promotion event.
  • Assurance fee for the elasticity assurance: USD 100
  • Term of the elasticity assurance: one month
  • Quantity of instances: 1
  • Pay-as-you-go instance price: USD 10 per hour
  • Usage duration of the instance: 6 hours
Total fee = Assurance fee for the elasticity assurance + Fee for pay-as-you-go resources
  • Assurance fee for the elasticity assurance: USD 100
  • Fee for pay-as-you-go resources: USD 10 per hour × 6 hours = USD 60
  • Total fee: USD 100 + USD 60 = USD 160
Note
  • Elasticity assurances can ensure that you always have access to capacity when you want to create instances. During the term of an elasticity assurance, you can infinitely create or release pay-as-you-go instances from the reserved capacity.
  • If an instance created from the reserved capacity of an elasticity assurance is used for longer than the term of the elasticity assurance, the elasticity assurance is automatically released on expiration.
  • When an elasticity assurance is released, pay-as-you-go instances that were created from the reserved capacity are not affected and continue to run normally. The instances are billed at the pay-as-you-go rate after they are created.
Immediate capacity reservation Assume that an enterprise user purchased a 4-hour immediate capacity reservation for two ECS instances and created ECS Instances A and B from the reserved capacity. Assume that Instance A has been released after it was used for 3 hours and that Instance B has been released after it was used for 1 hour.
  • Pay-as-you-go instance price: USD 10 per hour
  • Term of the immediate capacity reservation: 4 hours
  • Usage duration of Instance A: 3 hours
  • Usage duration of Instance B: 1 hour
Total fee = Fee for the immediate capacity reservation + Fee for pay-as-you-go resources

Fee for the immediate capacity reservation = Fee for unused capacity + Fee for used capacity. The fee for used capacity is 0.

  • Fee for pay-as-you-go resources of Instance A: USD 10 per hour × 3 hours = USD 30
  • Fee for unused capacity for Instance A: USD 10 per hour × 1 hour = USD 10
  • Fee for pay-as-you-go resources of Instance B: USD 10 per hour × 1 hour = USD 10
  • Fee for unused capacity for Instance B: USD 10 per hour × 3 hours = USD 30
  • Fee for the immediate capacity reservation = USD 10 + USD 30 = USD 40
  • Fee for pay-as-you-go resources: USD 30 + USD 10 = USD 40
  • Total fee: USD 40 + USD 40 = USD 80
Note When an immediate capacity reservation is purchased to reserve capacity for a specific instance type, the capacity reservation begins immediately to be billed at the pay-as-you-go price of the instance type. Billing continues as long as the capacity reservation is present in your account, regardless of whether the capacity reservation is actually used to create instances. You can manually release a capacity reservation or wait for it to be automatically released on expiration.
  • Before a capacity reservation is used to create pay-as-you-go instances, you are charged only for the specified instance type.
  • After a capacity reservation is used to create pay-as-you-go instances, you are charged based on the configurations of the instances including the instance type, disks, and public bandwidth.

References