This topic describes how to merge reserved instances. If traffic to your instances increases, you can merge multiple reserved instances into a single reserved instance to match larger pay-as-you-go instances. For ease of description, the reserved instances to be merged are referred to as the original reserved instances. The resulting merged reserved instance is referred to as the destination reserved instance.

Prerequisites

  • The original reserved instances are purchased by using the same currency.
  • The original reserved instances are in the Active state.
  • The original reserved instances belong to the same region if they are regional reserved instances. The original reserved instances belong to the same zone if they are zonal reserved instances.
  • The original reserved instances have the same operating system and end time.
    Note The end time of a reserved instance is determined when you purchase the reserved instance, and is not necessarily the time when the reserved instance becomes inactive. For example, after you merge the reserved instances, the original reserved instances become inactive. However, the end time of the original reserved instances remains unchanged.
  • No ongoing requests for splitting, merging, or modifying reserved instances exist.

Background information

When you merge reserved instances, take note of the following items:
  • Reserved instances that belong to the gn6i and t5 instance families cannot be merged.
  • You can change the instance type of a reserved instance. However, you cannot change the instance family of a reserved instance.
  • You cannot change the zone or region of a reserved instance.
  • The number of pay-as-you-go instances to which the destination reserved instance can be applied cannot exceed 100.
  • The total computing power of the destination reserved instance must be equal to that of the original reserved instances. For more information about computing power, see Match between reserved instances and pay-as-you-go instances. The following figure shows an example of merging reserved instances.Merge reserved instances
  • The instance type of the destination reserved instance must be valid. For example, you cannot obtain an ecs.g5.5xlarge reserved instance because the ecs.g5.5xlarge instance type is not included in the g5 instance family, as shown in the following figure.Validity of the instance type of the destination reserved instance

Procedure

  1. Log on to the ECS console.
  2. In the left-side navigation pane, choose Instances & Images > Reserved Instances.
  3. On the Reserved Instances page, find an original reserved instance and click Merge in the Actions column.
  4. In the Merge Reserved Instances pane, select the reserved instances that you want to merge with the current reserved instance. Configure the name, instance type, and quantity of the destination reserved instance.
  5. Click OK.

Result

After you submit the request for instance merging, the original reserved instances enter the Updating state, and the destination reserved instance in the Creating state is displayed. You cannot cancel the ongoing request for merging reserved instances. If you want to roll back the change made by the merging operation, you can split the merged reserved instance to obtain the original reserved instances.

After the request for merging reserved instances is processed, you can obtain one of the following results:
  • If the reserved instances are merged:
    • The original reserved instances enter the Inactive state and expires on the hour when they are merged. The prices become USD 0.
    • The destination reserved instance enters the Active state and takes effect on the hour when the original reserved instances are merged. If the destination reserved instance is a zonal reserved instance, the type of reserved resources is updated automatically.
    • If the destination reserved instance matches pay-as-you-go instances, the billing discount provided by the reserved instance is applied to the matched pay-as-you-go instances starting from the hour when the destination reserved instance takes effect.
  • If the original reserved instances fail to be merged, they remain active.
Assume that you merged two ecs.g5.xlarge regional reserved instances into an ecs.g5.2xlarge regional reserved instance at 08:30 of May 29, 2020. The following figure shows the time when the original reserved instances expire and the time when the destination reserved instance takes effect.The time when the merging takes effect