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Auto Scaling:CompleteLifecycleAction

Last Updated:Jun 06, 2024

Ends the timeout period of a lifecycle hook ahead of schedule. If you have created a lifecycle hook for your scaling group, you can call the CompleteLifecycleAction operation to end the timeout period of the lifecycle hook ahead of schedule based on your business requirements.

Operation description

When you manually cut short the timeout period of a lifecycle hook, Auto Scaling proceeds with one of the following actions based on the predefined settings: responding to the scaling request, aborting the scaling request, and initiating a rollback process.


OpenAPI Explorer automatically calculates the signature value. For your convenience, we recommend that you call this operation in OpenAPI Explorer.

Authorization information

There is currently no authorization information disclosed in the API.

Request parameters


The ID of the lifecycle hook.


The token of the lifecycle hook. You can obtain this token by using a Message Service (MNS) queue or an MNS topic that is specified for the lifecycle hook.


The action that you want Auto Scaling to perform after the lifecycle hook times out. Valid values:

  • CONTINUE: Auto Scaling continues to respond to a scale-in or scale-out request.
  • ABANDON: Auto Scaling releases Elastic Compute Service (ECS) instances that are created during scale-out activities or removes ECS instances from the scaling group during scale-in activities.
  • ROLLBACK: For scale-in activities, Auto Scaling rejects the requests to release ECS instances but rolls back ECS instances. For scale-out activities, the ROLLBACK setting has the same effect as the ABANDON setting.

If you do not specify this parameter, Auto Scaling performs the action that is specified by the DefaultResult parameter after the lifecycle hook times out.

If multiple lifecycle hooks exist in a scaling group and the lifecycle hooks are triggered at the same time, the following rules apply:

  • For scale-in activities, when lifecycle hooks whose LifecycleActionResult parameter is set to ABANDON or ROLLBACK time out, other lifecycle hooks time out ahead of schedule.
  • For scale-in and scale-out activities, if you set the LifecycleActionResult parameter for all lifecycle hooks to CONTINUE, Auto Scaling performs the next action only after the last lifecycle hook times out. The action that Auto Scaling performs varies based on the value that you specify for the LifecycleActionResult parameter of the lifecycle hook that last times out.

The client token that is used to ensure the idempotence of the request.

You can use the client to generate the token, but you must make sure that the token is unique among different requests. The token can contain only ASCII characters and cannot exceed 64 characters in length. For more information, see Ensure idempotence.


The region ID of the scaling group.


Response parameters


The ID of the request.



Sample success responses


  "RequestId": "473469C7-AA6F-4DC5-B3DB-A3DC0DE****"

Error codes

For a list of error codes, visit the Service error codes.

Change history

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