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    Auto Scaling:RemoveInstances

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    Auto Scaling:RemoveInstances

    Last Updated:Jul 24, 2024

    Removes one or more instances from a scaling group. If your scaling group is enabled and contains no ongoing scaling activities, you can call the RemoveInstances operation to remove instances that you no longer require from the scaling group.

    Operation description

    • Before you call this operation, make sure that the following requirements are met:

      • The scaling group is in the Active state.
      • No scaling activity is in progress within the scaling group.
    Note If no scaling activity is in progress within the scaling group, you can call the operation even within the cooldown period.
    • If an ECS instance is automatically created by Auto Scaling, or if an ECS instance is manually added to a scaling group and managed by the scaling group, the ECS instance is stopped in economical mode or is released after the instance is removed from the scaling group.
    • If an ECS instance is manually added to a scaling group and is not managed by the scaling group, the ECS instance is not stopped or released after the instance is removed from the scaling group.
    • If the difference between the number of existing ECS instances specified by the TotalCapacity parameter and the number of ECS instances that you call this operation to remove is less than the value of the MinSize parameter, the call fails.

    A successful call only means that Auto Scaling accepts the request. The scaling activity may still fail. You can obtain the status of a scaling activity based on the value of the ScalingActivityId parameter in the response.

    Debugging

    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

    ParameterTypeRequiredDescriptionExample
    ScalingGroupIdstringYes

    The ID of the scaling group.

    		asg-bp18p2yfxow2dloq****
    RemovePolicystringNo

    The action subsequent to the removal of the Elastic Compute Service (ECS) instances. Valid values:

    • recycle: The ECS instances enter the Economical Mode.

      **

      Note This setting is applicable only if you set ScalingPolicy to recycle.

    • release: The ECS instances are released.

    ScalingPolicy of the CreateScalingGroup operation specifies the reclaim mode of the scaling group while RemovePolicy of the RemoveInstances operation specifies the subsequent action when an ECS instance is removed from the scaling group. Examples:

    • If you set ScalingPolicy and RemovePolicy to recycle, the ECS instances enter the Economical Mode when they are removed.
    • If you set ScalingPolicy to recycle and RemovePolicy to release, the ECS instances are released when they are removed.
    • If you set ScalingPolicy to release and RemovePolicy to recycle, the ECS instances are released when they are removed.
    • If you set ScalingPolicy and RemovePolicy to release, the ECS instances are released when they are removed.

    Default value: release.

    		release
    DecreaseDesiredCapacitybooleanNo

    Specifies whether to adjust the expected number of ECS instances in the scaling group. Valid values:

    • true: After ECS instances are removed from the scaling group, the expected number of ECS instances in the scaling group decreases.
    • false: After ECS instances are removed from the scaling group, the expected number of ECS instances in the scaling group remains unchanged.

    Default value: true.

    		true
    IgnoreInvalidInstancebooleanNo

    Specifies whether to ignore invalid instances when you remove a batch of instances from the scaling group. Valid values:

    • true: ignores invalid instances. If invalid instances exist and valid instances are deleted, the corresponding scaling activity enters the Warning state. You can check the scaling activity details to view the invalid instances that are ignored.
    • false: does not ignore invalid instances. If invalid instances exist in the batch of instances that you want to remove from the scaling group, an error is reported.

    Default value: false.

    		false
    InstanceIdsarrayYes

    The IDs of the ECS instances that you want to remove from the scaling group.

    stringYes

    The ID of the ECS instance that you want to remove from the scaling group.

    		i-28wt4****
    RegionIdstringNo

    The region ID of the scaling group.

    		cn-qingdao
    ClientTokenstringNo

    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 How to ensure idempotence.

    		123e4567-e89b-12d3-a456-42665544****

    Response parameters

    ParameterTypeDescriptionExample
    object
    ScalingActivityIdstring

    The ID of the scaling activity.

    		asa-bp175o6f6ego3r2j****
    RequestIdstring

    The request ID.

    		473469C7-AA6F-4DC5-B3DB-A3DC0DE3C83E

    Examples

    Sample success responses

    JSONformat

    {
  "ScalingActivityId": "asa-bp175o6f6ego3r2j****",
  "RequestId": "473469C7-AA6F-4DC5-B3DB-A3DC0DE3C83E"
}

    Error codes

    HTTP status codeError codeError message
    500InternalErrorThe request processing has failed due to some unknown error, exception or failure.

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

    Change history

    Change timeSummary of changesOperation
    2024-05-21The Error code has changed. The request parameters of the API has changedView Change Details