This topic describes how to purchase a Reserved Instance (RI).

Before you begin:

  • Before purchasing an RI, make sure that the Pay-As-You-Go instances to be matched do not exceed the Limitations.
  • The matching status between an RI and a Pay-As-You-Go instance cannot be manually managed. We recommend that you read the Matching rules of RIs to fully understand the matching rule requirements.


  1. Log on to the ECS console.
  2. In the left-side navigation pane, click Reserved Instances. If you have not tried this feature, click Apply to apply for testing.
  3. On the Reserved Instances page, click Purchase Reserved Instance.
  4. Set the region-related parameters.
    1. Select a region.
    2. Set Resource Reservation.
      Note Only zonal RIs support resource reservation. However, regional RIs can apply to Pay-As-You-Go instances of different sizes or in different zones.
  5. Configure the RI.
    1. Select an Instance Type.
      Note You must select an instance size when you purchase a regional RI, but you do not need to specify the instance size for the RI to match Pay-As-You-Go instances.
    2. Select Payment Option.

      The options are All Upfront, Partial Upfront, and No Upfront. For more information, see Reserved Instance billing.

  6. Set the purchase parameters.
    1. (Optional) Enter a Name.
    2. Enter a Term.

      The options are 1 Year(s) and 3 Year(s).

    3. Enter an Instance Count.

      The Reserved Instance can match the specified count of Pay-As-You-Go instances with the specified instance type. For example, if the instance type is ecs.g5.large and instance count is 3, the Reserved Instance can match 3 Pay-As-You-Go instances with instance type as ecs.g5.large.

  7. Read and confirm that you agree to the ECS Service Level Agreement and Product Terms of Service, and then click Purchase.
  8. In the confirmation dialog box, confirm the parameters, and then click Create Order.
  9. Confirm the payment information, and then click Pay.

What to do next

After you have successfully purchased an RI, you can immediately benefit from the billing discount when the RI matches one or more Pay-As-You-Go instances. You can also Manage Reserved Instances to quickly adjust to any changes made to your Pay-As-You-Go instances.