Adding a Backend Server¶

Function¶

This API is used to add a backend server.

Constraints¶

When you add backend servers, note the following:

Two backend servers in the same backend server group must have different IP addresses and ports.
If no subnets are specified during cloud server creation, cross-VPC backend servers can be added. In this case, address must be set to an IPv4 address, the protocol of the backend server group must be TCP, HTTP, or HTTPS, and cross-VPC backend must have been enabled for the load balancer.
If a subnet is specified during cloud server creation, the subnet must be in the same VPC as the subnet from which the virtual IP address bound to the load balancer is assigned.
If the backend server group supports IPv4/IPv6 dual stack, address can be an IPv4 or IPv6 address. The value of address depends on the IP address version of the backend server group.

URI¶

POST /v3/{project_id}/elb/pools/{pool_id}/members

**Table 1** Path Parameters¶
Parameter	Mandatory	Type	Description
pool_id	Yes	String	Specifies the ID of the backend server group.
project_id	Yes	String	Specifies the project ID.

Request Parameters¶

**Table 2** Request header parameters¶
Parameter	Mandatory	Type	Description
X-Auth-Token	Yes	String	Specifies the token used for IAM authentication.

**Table 3** Request body parameters¶
Parameter	Mandatory	Type	Description
member	Yes	CreateMemberOption object	Specifies request parameters for creating a backend server.

**Table 4** CreateMemberOption¶
Parameter	Mandatory	Type	Description
address	Yes	String	Specifies the IP address of the backend server. The IP address must be in the subnet specified by subnet_cidr_id, for example, 192.168.3.11. The IP address can only be the IP address of the primary NIC. If subnet_cidr_id is left blank, cross-VPC backend is enabled. In this case, these servers must use IPv4 addresses. Minimum: 1 Maximum: 64
admin_state_up	No	Boolean	Specifies the administrative status of the backend server. Although this parameter can be used in the APIs for creating and updating backend servers, its actual value depends on whether cloud servers exist. If cloud servers exist, the value is true. Otherwise, the value is false.
name	No	String	Specifies the backend server name. Minimum: 0 Maximum: 255
project_id	No	String	Specifies the project ID. Minimum: 1 Maximum: 32
protocol_port	Yes	Integer	Specifies the port used by the backend server to receive requests. Minimum: 1 Maximum: 65535
subnet_cidr_id	No	String	Specifies the ID of the subnet where the backend server works. This subnet must be in the same VPC as the subnet of the load balancer with which the backend server is associated. Only IPv4 subnets are supported. This parameter is mandatory if cross-VPC backend is disabled. If this parameter is left blank, cross-VPC backend servers can be added. In this case, IP addresses of these servers must be IPv4 addresses, the protocol of the backend server group must be TCP, HTTP, or HTTPS, and cross-VPC backend must have been enabled for the load balancer. Minimum: 1 Maximum: 36
weight	No	Integer	Specifies the weight of the backend server. Requests are routed to backend servers in the same backend server group based on their weights. If the weight is 0, the backend server will not accept new requests. This parameter is invalid when lb_algorithm is set to SOURCE_IP for the backend server group that contains the backend server. Minimum: 0 Maximum: 100 Default: 1

Response Parameters¶

Status code: 201

**Table 5** Response body parameters¶
Parameter	Type	Description
request_id	String	Specifies the request ID. The value is automatically generated.
member	Member object	Specifies the backend server.

**Table 6** Member¶
Parameter	Type	Description
address	String	Specifies the IP address of the backend server. The IP address must be in the subnet specified by subnet_cidr_id, for example, 192.168.3.11. The IP address can only be the IP address of the primary NIC.
admin_state_up	Boolean	Specifies the administrative status of the backend server. Although this parameter can be used in the APIs for creating and updating backend servers, its actual value depends on whether cloud servers exist. If cloud servers exist, the value is true. Otherwise, the value is false. Default: true
id	String	Specifies the backend server ID.
name	String	Specifies the backend server name.
operating_status	String	Specifies the operating status of the backend server. The value can be one of the following: ONLINE: The backend server is running normally. NO_MONITOR: No health check is configured for the backend server group to which the backend server belongs. OFFLINE: The cloud server used as the backend server is stopped or does not exist.
project_id	String	Specifies the project ID.
protocol_port	Integer	Specifies the port used by the backend server to receive requests. Minimum: 1 Maximum: 65535
subnet_cidr_id	String	Specifies the ID of the subnet where the backend server works. This subnet must be in the VPC as the subnet of the load balancer associated with the backend server. Only IPv4 subnets are supported. If the value is left blank, the backend server is not in the load balancer's VPC.
weight	Integer	Specifies the weight of the backend server. Requests are routed to backend servers in the same backend server group based on their weights. If the weight is 0, the backend server will not accept new requests. This parameter is invalid when lb_algorithm is set to SOURCE_IP for the backend server group that contains the backend server. Minimum: 0 Maximum: 100 Default: 1
ip_version	String	This is a read-only attribute, which is automatically generated based on the address parameter. The value can be v4 or v6. Default: v4

Example Requests¶

POST

https://{elb_endpoint}/v3/99a3fff0d03c428eac3678da6a7d0f24/elb/pools/36ce7086-a496-4666-9064-5ba0e6840c75/members

{
  "member" : {
    "subnet_cidr_id" : "c09f620e-3492-4429-ac15-445d5dd9ca74",
    "protocol_port" : 89,
    "name" : "My member",
    "address" : "120.10.10.16"
  }
}

Example Responses¶

Status code: 201

Successful request.

{
  "member" : {
    "name" : "My member",
    "weight" : 1,
    "admin_state_up" : false,
    "subnet_cidr_id" : "c09f620e-3492-4429-ac15-445d5dd9ca74",
    "project_id" : "99a3fff0d03c428eac3678da6a7d0f24",
    "address" : "120.10.10.16",
    "protocol_port" : 89,
    "id" : "1923923e-fe8a-484f-bdbc-e11559b1f48f",
    "operating_status" : "NO_MONITOR",
    "ip_version" : "v4"
  },
  "request_id" : "f354090d-41db-41e0-89c6-7a943ec50792"
}

Status Codes¶

Status Code	Description
201	Successful request.

Error Codes¶

See Error Codes.

last updated: 2023-03-02 13:42