AttachServerGroups - Auto Scaling - Alibaba Cloud Documentation Center

Attaches server groups to a scaling group. To seamlessly adjust the number of instances in response to changes in your business workload or to maintain the uninterrupted accessibility of your application, you can call the AttachServerGroups operation. By attaching Application Load Balancer (ALB) or Network Load Balancer (NLB) server groups to your scaling group, this operation enables Auto Scaling to automatically tailor your computing capacity to your business needs. Furthermore, it optimizes traffic routing by dynamically allocating incoming requests based on current workload patterns, which significantly improves the stability and performance of your application.

Debugging

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Debug

Authorization information

The following table shows the authorization information corresponding to the API. The authorization information can be used in the Action policy element to grant a RAM user or RAM role the permissions to call this API operation. Description:

Operation: the value that you can use in the Action element to specify the operation on a resource.
Access level: the access level of each operation. The levels are read, write, and list.
Resource type: the type of the resource on which you can authorize the RAM user or the RAM role to perform the operation. Take note of the following items:
- The required resource types are displayed in bold characters.
- If the permissions cannot be granted at the resource level, All Resources is used in the Resource type column of the operation.
Condition Key: the condition key that is defined by the cloud service.
Associated operation: other operations that the RAM user or the RAM role must have permissions to perform to complete the operation. To complete the operation, the RAM user or the RAM role must have the permissions to perform the associated operations.

Operation	Access level	Resource type	Condition key	Associated operation
ess:AttachServerGroups	update	ScalingGroup acs:ess:{#regionId}:{#accountId}:scalinggroup/{#ScalingGroupId}	none	none

Request parameters

Parameter	Type	Required	Description	Example
RegionId	string	Yes	The region ID of the scaling group.	cn-hangzhou
ScalingGroupId	string	Yes	The ID of the scaling group.	asg-bp1fo0dbtsbmqa9h****
ClientToken	string	No	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.	123e4567-e89b-12d3-a456-42665544****
ForceAttach	boolean	No	Specifies whether to add the existing Elastic Compute Service (ECS) instances or elastic container instances in the scaling group to the server group. Valid values: true false Default value: false.	false
ServerGroups	array<object>	Yes	The information about the server groups.
	object	Yes	Details of the server group.
ServerGroupId	string	Yes	The ID of the server group.	sgp-5yc3bd9lfyh*****
Type	string	Yes	The type of the server group. Valid values: ALB NLB	ALB
Weight	integer	Yes	The weight of an ECS instance or elastic container instance as a backend server of the server group. Valid values: 0 to 100. If you assign a higher weight to an instance, the instance is allocated a larger proportion of access requests. If you assign zero weight to an instance, the instance is allocated no access requests.	100
Port	integer	Yes	The port used by ECS instances or elastic container instances after being added as backend servers to the server group. Valid values: 1 to 65535.	22

Response parameters

Parameter	Type	Description	Example
	object
ScalingActivityId	string	The ID of the scaling activity. During the scaling activity, the server group is attached to the scaling group and the existing ECS instances or elastic container instances in the scaling group are added to the server group. Note This parameter is returned only if you set ForceAttach to true.	asa-bp1c9djwrgxjyk31****
RequestId	string	The ID of the request.	473469C7-AA6F-4DC5-B3DB-A3DC0DE3****

Examples

Sample success responses

JSONformat

{
  "ScalingActivityId": "asa-bp1c9djwrgxjyk31****",
  "RequestId": "473469C7-AA6F-4DC5-B3DB-A3DC0DE3****"
}

Error codes

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

Change history

Change time	Summary of changes	Operation
2023-12-18	The internal configuration of the API is changed, but the call is not affected	View Change Details