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, IP as 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 IP as a Backend Server 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 where the load balancer resides.

  • If the backend server group supports IPv4/IPv6 dual stack, address can be an IPv4 address or an IPv6 address. If the backend server group supports only IPv4, address can only be an IPv4 address.

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 the backend server.

Table 4 CreateMemberOption

Parameter

Mandatory

Type

Description

address

Yes

String

Specifies the private IP address bound to the backend server.

  • If subnet_cidr_id is left blank, IP as a Backend Server is enabled. In this case, the IP address must be an IPv4 address.

  • If subnet_cidr_id is not left blank, the IP address can be IPv4 or IPv6. It must be in the subnet specified by subnet_cidr_id and can only be bound to the primary NIC of the backend server.

Minimum: 1

Maximum: 64

admin_state_up

No

Boolean

Specifies the administrative status of the backend server. The value can be true or false.

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 IPv4 or IPv6 subnet where the backend server resides.

Note:

  • The IPv4 or IPv6 subnet must be in the same VPC as the subnet of the load balancer.

  • If this parameter is not passed, IP as a Backend Server has been enabled for the load balancer. In this case, IP as Backend servers must use private IPv4 addresses, and the protocol of the backend server group must be TCP, HTTP, or HTTPS.

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.

The value ranges from 0 to 100, and the default value is 1. The larger the weight is, the higher proportion of requests the backend server receives. If the weight is set to 0, the backend server will not accept new requests.

If lb_algorithm is set to SOURCE_IP, this parameter will not take effect.

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

id

String

Specifies the backend server ID.

Note:

The value of this parameter is not the ID of the server but an ID automatically generated for the backend server that has already associated with the load balancer.

name

String

Specifies the backend server name.

project_id

String

Specifies the project ID of the backend server.

admin_state_up

Boolean

Specifies the administrative status of the backend server. The value can be true or false.

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.

subnet_cidr_id

String

Specifies the ID of the IPv4 or IPv6 subnet where the backend server resides.

This parameter can be left blank, indicating that IP as a Backend Server has been enabled for the load balancer. In this case, IP addresses of these servers must be IPv4 addresses, and the protocol of the backend server group must be TCP, HTTP, or HTTPS.

The IPv4 or IPv6 subnet must be in the same VPC as the subnet of the load balancer.

protocol_port

Integer

Specifies the port used by the backend server to receive requests.

Minimum: 1

Maximum: 65535

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.

The value ranges from 0 to 100, and the default value is 1. The larger the weight is, the higher proportion of requests the backend server receives. If the weight is set to 0, the backend server will not accept new requests.

If lb_algorithm is set to SOURCE_IP, this parameter will not take effect.

Minimum: 0

Maximum: 100

address

String

Specifies the private IP address bound to the backend server.

  • If subnet_cidr_id is left blank, IP as a Backend Server is enabled. In this case, the IP address must be an IPv4 address.

  • If subnet_cidr_id is not left blank, the IP address can be IPv4 or IPv6. It must be in the subnet specified by subnet_cidr_id and can only be bound to the primary NIC of the backend server.

ip_version

String

Specifies the IP version supported by the backend server. The value can be v4 (IPv4) or v6 (IPv6), depending on the value of address returned by the system.

operating_status

String

Specifies the health status of the backend server if listener_id under status is not specified. 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.

status

Array of MemberStatus objects

Specifies the health status of the backend server if listener_id is specified.

loadbalancer_id

String

Specifies the ID of the load balancer with which the backend server is associated.

This parameter is unsupported. Please do not use it.

loadbalancers

Array of ResourceID objects

Specifies the IDs of the load balancers associated with the backend server.

This parameter is unsupported. Please do not use it.

created_at

String

Specifies the time when a backend server was added. The format is yyyy-MM-dd'T'HH:mm:ss'Z' (UTC time).

This is a new field in this version, and it will not be returned for resources associated with existing dedicated load balancers and for resources associated with existing and new shared load balancers.

updated_at

String

Specifies the time when a backend server was updated. The format is yyyy-MM-dd'T'HH:mm:ss'Z' (UTC time).

This is a new field in this version, and it will not be returned for resources associated with existing dedicated load balancers and for resources associated with existing and new shared load balancers.

member_type

String

Specifies the type of the backend server. Values:

  • ip: IP as Backend servers

  • instance: ECSs used as backend servers

instance_id

String

Specifies the ID of the ECS used as the backend server. If this parameter is left blank, the backend server is not an ECS. For example, it may be an IP address.

Table 7 MemberStatus

Parameter

Type

Description

listener_id

String

Specifies the listener ID.

operating_status

String

Specifies the health 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.

Table 8 ResourceID

Parameter

Type

Description

id

String

Specifies the resource ID.

Example Requests

  • Example 1: Adding a backend server

    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 2: Adding a server of IP as a Backend Server

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

{
  "member" : {
    "protocol_port" : 89,
    "name" : "My member",
    "address" : "120.10.10.16"
  }
}

Example Responses

Status code: 201

Normal response to POST requests.

{
  "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",
    "status" : [ {
      "listener_id" : "427eee03-b569-4d6c-b1f1-712032f7ec2d",
      "operating_status" : "NO_MONITOR"
    } ],
    "ip_version" : "v4"
  },
  "request_id" : "f354090d-41db-41e0-89c6-7a943ec50792"
}

Status Codes

Status Code

Description

201

Normal response to POST requests.

Error Codes

See Error Codes.

last updated: 2024-11-13 14:50 UTC - commit: dc0473f339644f421ca4d648c4746583f80203ae