You can call ModifyReservedInstances to modify Reserved Instances (RIs).


Before you change RIs, note the following:

  • The region of an RI cannot be changed. You can only change the zone of an RI, change region-level RIs to zone-level RIs, or change zone-level RIs to region-level RIs.
  • The instance type family of an RI cannot be modified. Only the size of an RI can be modified.
  • If the RIs to be merged are region-level RIs, they must be in the same region. If the RIs to be merged are zone-level RIs, they must be in the same zone.
  • The RIs to be merged must have the same expiration date.
  • After an RI is split or multiple RIs are merged, the initial RI or RIs will expire immediately.

Request parameters

Name Type Required Description
Action String Yes A parameter required by the system. Value: ModifyReservedInstances.
RegionId String Yes ID of the region to which the RI belongs. You can call DescribeRegions to view the latest region list.
ReservedInstanceId.N String Yes ID of the RI. N is an integer from 1 to 20.
Configuration.N Configuration Yes Configuration attribute of the target RI
DryRun Boolean No Specifies whether to check this request only.
  • true: A check request is sent, but no instance is created. The system checks whether the required parameters are set, and also checks the request format, service limits, and available ECS instances. If the request does not pass the check, an error is returned. If the request passes the check, the error code DryRunOperation is returned.
  • false: A check request is sent, and an instance is created after the request passes the check.

Default value: false.

The following table describes the parameters of the Configuration data type.

Name Type Required Description
ReservedInstanceName String No Name of the RI. The name must be a string of 2 to 128 characters in length and can contain letters, numbers, colons (:), underscores (_), and hyphens. It must start with a letter. It cannot start with http:// or https://.
InstanceType String Yes Instance type of the RI. For more information, see Instance type families.
Scope String Yes Scope of the RI. Optional values:
  • Region: region-level
  • Zone: zone-level

Default value: Region.

ZoneId String No ID of the zone to which the RI belongs. When Scope is set to Zone, this parameter is required. For information about the zone list, see DescribeZones.
InstanceAmount Integer Yes Number of instances allocated to an RI (An RI is a coupon that includes one or more allocated instances.)

Response parameters

Name Type Description
RequestId String Request ID
ReservedInstanceIdSets List List of RI IDs. The IDs in the list are the unique identities to access the RIs.