Use SetBackendServers to specify weights for backend servers - Server Load Balancer

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Test

RAM authorization

The table below describes the authorization required to call this API. You can define it in a Resource Access Management (RAM) policy. The table's columns are detailed below:

Action: The actions can be used in the Action element of RAM permission policy statements to grant permissions to perform the operation.
API: The API that you can call to perform the action.
Access level: The predefined level of access granted for each API. Valid values: create, list, get, update, and delete.
Resource type: The type of the resource that supports authorization to perform the action. It indicates if the action supports resource-level permission. The specified resource must be compatible with the action. Otherwise, the policy will be ineffective.
- For APIs with resource-level permissions, required resource types are marked with an asterisk (*). Specify the corresponding Alibaba Cloud Resource Name (ARN) in the Resource element of the policy.
- For APIs without resource-level permissions, it is shown as All Resources. Use an asterisk (*) in the Resource element of the policy.
Condition key: The condition keys defined by the service. The key allows for granular control, applying to either actions alone or actions associated with specific resources. In addition to service-specific condition keys, Alibaba Cloud provides a set of common condition keys applicable across all RAM-supported services.
Dependent action: The dependent actions required to run the action. To complete the action, the RAM user or the RAM role must have the permissions to perform all dependent actions.

Action

Access level

Resource type

Condition key

Dependent action

slb:SetBackendServers

update

instance

acs:ecs:{#regionId}:{#accountId}:instance/{#instanceId}

*loadbalancer

acs:slb:{#regionId}:{#accountId}:loadbalancer/{#loadbalancerId}

ecs:tag
slb:tag
slb:tag

None

Request parameters

Parameter	Type	Required	Description	Example
RegionId	string	No	The region ID of the Classic Load Balancer (CLB) instance.	cn-hangzhou
LoadBalancerId	string	Yes	The ID of the CLB instance.	lb-bp1qjwo61pqz3a******
BackendServers	string	No	The backend servers that you want to add. Configure the following parameters: ServerId: Required. The ID of the backend server. Specify the value in a string. You can specify the ID of an Elastic Compute Service (ECS) instance, an elastic network interface (ENI), or an elastic container instance. If you set ServerId to the ID of an ENI or an elastic container instance, you must configure the Type parameter. Weight: the weight of the backend server. Valid values: 0 to 100. Default value: 100. If you set the weight of a backend server to 0, no requests are forwarded to the backend server. Description: Optional. The description of the backend server. Specify the value in a string. The description must be 1 to 80 characters in length, and can contain letters, digits, hyphens (-), forward slashes (/), periods (.), and underscores (_). Type: the type of the backend server. Valid values: ecs (default): ECS instance eni: ENI eci: elastic container instance Note You can specify ENIs and elastic container instances as backend servers only for high-performance CLB instances. ServerIp: the IP address of the ENI or elastic container instance. Port: the backend port. Examples: ECS instance: `[{ "ServerId": "i-xxxxxxxxx", "Weight": "100", "Type": "ecs", "Port":"80","Description":"test-112" }]` ENI: `[{ "ServerId": "eni-xxxxxxxxx", "Weight": "100", "Type": "eni", "ServerIp": "192.168..", "Port":"80","Description":"test-112" }]` ENI with multiple IP addresses: `[{ "ServerId": "eni-xxxxxxxxx", "Weight": "100", "Type": "eni", "ServerIp": "192.168..", "Port":"80","Description":"test-113" },{ "ServerId": "eni-xxxxxxxxx", "Weight": "100", "Type": "eni", "ServerIp": "172.166..", "Port":"80","Description":"test-113" }]` Elastic container instance: `[{ "ServerId": "eci-xxxxxxxxx", "Weight": "100", "Type": "eci", "ServerIp": "192.168..", "Port":"80","Description":"test-114" }]` Note You can add only running backend servers to a CLB instance. You can specify at most 20 backend servers in each call.	[{ "ServerId": "eni-xxxxxxxxx", "Weight": "100", "Type": "eni", "ServerIp": "192.168..", "Port":"80","Description":"test-112" },{ "ServerId": "eni-xxxxxxxxx", "Weight": "100", "Type": "eni", "ServerIp": "172.166..", "Port":"80","Description":"test-113" }]

Response elements

Element	Type	Description	Example
	object
LoadBalancerId	string	The ID of the CLB instance.	lb-bp1qjwo61pqz3a******
RequestId	string	The request ID.	365F4154-92F6-4AE4-92F8-7F******
BackendServers	object
BackendServer	array<object>	The backend servers.
	object
Type	string	The type of backend server. Valid values: ecs (default): ECS instance eni: ENI eci: elastic container instance	eni
Weight	string	The weight of the backend server.	100
Description	string	The description of the backend server.	The description of the backend server.
ServerId	string	The ID of the server group.	eni-hhshhs****

Examples

Success response

JSON format

{
  "LoadBalancerId": "lb-bp1qjwo61pqz3a******",
  "RequestId": "365F4154-92F6-4AE4-92F8-7F******",
  "BackendServers": {
    "BackendServer": [
      {
        "Type": "eni",
        "Weight": "100",
        "Description": "The description of the backend server.",
        "ServerId": "eni-hhshhs****"
      }
    ]
  }
}

Error codes

HTTP status code	Error code	Error message	Description
400	Mismatched.ZoneId	The zone of the server is not matched with the cloud box loadbalancer.

See Error Codes for a complete list.

Release notes

See Release Notes for a complete list.