Modifies the configurations of backend servers in a server group, such as the weight and description.


OpenAPI Explorer automatically calculates the signature value. For your convenience, we recommend that you call this operation in OpenAPI Explorer. OpenAPI Explorer dynamically generates the sample code of the operation for different SDKs.

Request parameters

Parameter Type Required Example Description
Action String Yes UpdateServerGroupServersAttribute

The operation that you want to perform. Set the value to UpdateServerGroupServersAttribute.

ServerGroupId String Yes sgp-atstuj3rtop****

The ID of the server group.

Servers Array Yes

The backend servers whose configurations you want to modify. You can specify up to 40 backend servers in each call.

Description String No test

The description of the backend server. The description must be 2 to 256 characters in length and can contain letters, digits, periods (.), underscores (_), hyphens (-), commas (,), semicolons (;), forward slashes (/), and at signs (@).

Port Integer No 80

The port used by the backend server. Valid values: 1 to 65535.

Note You do not need to specify this parameter if ServerType is set to Fc.
ServerId String Yes i-bp1f9kdprbgy9uiu****

The ID of the backend server.

  • If ServerType is set to Ecs, Eni, or Eci, set the ServerId parameter to the ID of an Elastic Compute Service (ECS) instance, an elastic network interface (ENI), or an elastic container instance.
  • If ServerType is set to Ip, set the ServerId parameter to an IP address.
  • If ServerType is set to Fc, set the ServerId parameter to the Alibaba Cloud Resource Name (ARN) of a function.
ServerIp String No

The IP address in inclusive ENI mode.

ServerType String Yes Ecs

The type of the backend server. Valid values:

  • Ecs: an ECS instance
  • Eni: an ENI
  • Eci: an elastic container instance
  • Ip: an IP address
  • Fc: a function
Weight Integer No 100

The weight of the backend server. Valid values: 0 to 100. Default value: 100. If the weight of a backend server is set to 0, no requests are forwarded to the backend server.

Note You do not need to specify this parameter if ServerType is set to Fc.
ClientToken String No 593B0448-D13E-4C56-AC0D-FDF0FDE0E9A3

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

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

Note If you do not set this parameter, the system automatically uses RequestId as ClientToken. RequestId may be different for each API request.
DryRun Boolean No false

Specifies whether to only precheck this request. Valid values:

  • true: prechecks the request without creating the resource. The system prechecks the required parameters, request syntax, and limits. If the request fails to pass the precheck, an error message is returned. If the request passes the precheck, the DryRunOperation error code is returned.
  • false (default): sends the API request. If the request passes the precheck, a 2xx HTTP status code is returned and the operation is performed.

Response parameters

Parameter Type Example Description
JobId String 72dcd26b-f12d-4c27-b3af-18f6aed5****

The ID of the asynchronous task.

RequestId String 365F4154-92F6-4AE4-92F8-7FF34B540710

The ID of the request.


Sample requests

&Common request parameters

Sample success responses

XML format

HTTP/1.1 200 OK


JSON format

HTTP/1.1 200 OK

  "JobId" : "72dcd26b-f12d-4c27-b3af-18f6aed5****",
  "RequestId" : "365F4154-92F6-4AE4-92F8-7FF34B540710"

Error codes

HttpCode Error code Error message Description
400 IncorrectStatus.ServerGroup The status of %s [%s] is incorrect. The error message returned because the server group is in a state that does not support the operation.
404 ResourceNotFound.ServerGroup The specified resource %s is not found. The error message returned because the specified resource %s does not exist.

For a list of error codes, visit the API Error Center.