Viewing Details of a Backend Server Group¶

Function¶

This API is used to view details of a backend server group.

URI¶

GET /v3/{project_id}/elb/pools/{pool_id}

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

Request Parameters¶

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

Response Parameters¶

Status code: 200

**Table 3** Response body parameters¶
Parameter	Type	Description
request_id	String	Specifies the request ID. The value is automatically generated.
pool	Pool object	Specifies the backend server group.

**Table 4** Pool¶
Parameter	Type	Description
admin_state_up	Boolean	Specifies the administrative status of the backend server group. The value can only be true. This parameter is unsupported. Please do not use it.
description	String	Provides supplementary information about the backend server group.
healthmonitor_id	String	Specifies the ID of the health check configured for the backend server group.
id	String	Specifies the backend server group ID.
lb_algorithm	String	Specifies the load balancing algorithm used by the load balancer to route requests to backend servers in the associated backend server group. The value can be one of the following: ROUND_ROBIN: weighted round robin LEAST_CONNECTIONS: weighted least connections SOURCE_IP: source IP hash QUIC_CID: connection ID Note: If the value is SOURCE_IP, the weight parameter will not take effect for backend servers. QUIC_CID is supported only when the protocol of the backend server group is QUIC.
listeners	Array of ListenerRef objects	Specifies the IDs of the listeners with which the backend server group is associated.
loadbalancers	Array of LoadBalancerRef objects	Specifies the IDs of the load balancers with which the backend server group is associated.
members	Array of MemberRef objects	Specifies the IDs of the backend servers in the backend server group.
name	String	Specifies the backend server group name.
project_id	String	Specifies the project ID.
protocol	String	Specifies the protocol used by the backend server group to receive requests. The value can be TCP, UDP, HTTP, HTTPS, or QUIC. If the listener's protocol is UDP, the protocol of the backend server group must be UDP. If the listener's protocol is TCP, the protocol of the backend server group must be TCP. If the listener's protocol is HTTP, the protocol of the backend server group must be HTTP. If the listener's protocol is HTTPS, the protocol of the backend server group can be HTTP or HTTPS. If the listener's protocol is TERMINATED_HTTPS, the protocol of the backend server group must be HTTP. If the backend server group protocol is QUIC, sticky session must be enabled with type set to SOURCE_IP.
session_persistence	SessionPersistence object	Specifies the sticky session.
ip_version	String	Specifies the IP address version supported by the backend server group. IPv6 is unsupported. Only v4 will be returned.
slow_start	SlowStart object	Specifies slow start details. After you enable slow start, new backend servers added to the backend server group are warmed up, and the number of requests they can receive increases linearly during the configured slow start duration. This parameter can be used when the protocol of the backend server group is HTTP or HTTPS. An error will be returned if the protocol is not HTTP or HTTPS.
member_deletion_protection_enable	Boolean	Specifies whether to enable removal protection. true: Enable removal protection. false: Disable removal protection. Note Disable removal protection for all your resources before deleting your account.
created_at	String	Specifies the time when a backend server group was created. 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 when a backend server group 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.
vpc_id	String	Specifies the ID of the VPC where the backend server group works.
type	String	Specifies the type of the backend server group. Values: instance: Any type of backend servers can be added. vpc_id is mandatory. ip: Only IP as Backend servers can be added. vpc_id cannot be specified. "": Any type of backend servers can be added.
protection_status	String	Specifies the protection status. Value options: nonProtection (default): The load balancer is not protected. consoleProtection: Modification Protection is enabled on the console.
protection_reason	String	Specifies why the modification protection is enabled. Note: This parameter is valid only when protection_status is set to consoleProtection. The value can contain a maximum of 255 Unicode characters, excluding angle brackets (<>). Minimum: 0 Maximum: 255
az_affinity	AzAffinity object	Specifies how AZ affinity is configured for the backend server group. This parameter is unsupported. Please do not use it.

**Table 5** ListenerRef¶
Parameter	Type	Description
id	String	Specifies the listener ID.

**Table 6** LoadBalancerRef¶
Parameter	Type	Description
id	String	Specifies the load balancer ID.

**Table 7** MemberRef¶
Parameter	Type	Description
id	String	Specifies the backend server ID.

**Table 8** SessionPersistence¶
Parameter	Type	Description
cookie_name	String	Specifies the cookie name. The value can contain only letters, digits, hyphens (-), underscores (_), and periods (.). Note: This parameter will take effect only when type is set to APP_COOKIE.
type	String	Specifies the sticky session type. The value can be SOURCE_IP, HTTP_COOKIE, or APP_COOKIE. Note: If the protocol of the backend server group is TCP or UDP, only SOURCE_IP takes effect. For dedicated load balancers, if the protocol of the backend server group is HTTP or HTTPS, the value can only be HTTP_COOKIE. If the backend server group protocol is QUIC, sticky session must be enabled with type set to SOURCE_IP.
persistence_timeout	Integer	Specifies the stickiness duration, in minutes. This parameter will not take effect when type is set to APP_COOKIE. If the protocol of the backend server group is TCP, UDP, or QUIC, the value ranges from 1 to 60, and the default value is 1. If the protocol of the backend server group is HTTP or HTTPS, the value ranges from 1 to 1440, and the default value is 1440.

**Table 9** SlowStart¶
Parameter	Type	Description
enable	Boolean	Specifies whether to enable slow start. true: Enable slow start. false: Disable slow start. Default: false
duration	Integer	Specifies the slow start duration, in seconds. The value ranges from 30 to 1200, and the default value is 30. Minimum: 30 Maximum: 1200 Default: 30

**Table 10** AzAffinity¶
Parameter	Type	Description
enable	Boolean	Specifies whether to enable AZ affinity for the backend server group. If this parameter is set to true, ELB forwards traffic across the backend servers in the same AZ as the load balancer. Constraints: This parameter is available only for TCP and UDP backend server groups. This parameter is not available for backend server groups that are associated with TLS listeners. If the parameter is set to true, parameter pool_health will be ignored. The value can be false (disabled) or true (enabled).
az_minimum_healthy_member_percentage	Integer	Specifies a percentage that is used to determine the health of an AZ. If the percentage of healthy servers in the AZ of the load balancer falls below the specified value, az_unhealthy_fallback_strategy is triggered. az_minimum_healthy_member_percentage shows the ratio of healthy servers to total servers in a backend server group of an AZ. The number of healthy servers is rounded up. For example, in AZ A, if there are three backend servers in the backend server group and az_minimum_healthy_member_percentage is set to 66%, the number of healthy servers is rounded up to 2 (3 x 0.66 = 1.98). If there are fewer than two healthy servers in AZ A, az_unhealthy_fallback_strategy is triggered. If az_minimum_healthy_member_percentage is set to 67%, the number of healthy servers is rounded up to 3 (3 x 0.67 = 2.01). If there are fewer than three healthy servers in AZ A, az_unhealthy_fallback_strategy is triggered. Constraints: If enable is set to true, az_minimum_healthy_member_percentage and az_minimum_healthy_member_count cannot be set to -1 at the same time. If enable is set to true, either az_minimum_healthy_member_percentage or az_minimum_healthy_member_count must be set to -1. Value range: an integer ranging from -1 to 100. -1 indicates that az_minimum_healthy_member_count takes effect.
az_minimum_healthy_member_count	Integer	Specifies a number that is used to determine the health of an AZ. If the number of healthy servers in the AZ of the load balancer falls below the specified value, az_unhealthy_fallback_strategy is triggered. az_minimum_healthy_member_count shows the number of healthy servers to total servers in a backend server group of an AZ. Constraints: If enable is set to true, az_minimum_healthy_member_percentage and az_minimum_healthy_member_count cannot be set to -1 at the same time. If enable is set to true, either az_minimum_healthy_member_percentage or az_minimum_healthy_member_count must be set to -1. Value range: an integer ranging from -1 to 10000. -1 indicates that az_minimum_healthy_member_percentage takes effect.
az_unhealthy_fallback_strategy	String	Specifies how traffic will be distributed across backend servers in an AZ if the percentage or number of healthy servers in the AZ of the load balancer falls below the specified value. Value options: forward_to_all_member_of_local_az: forwards requests across all backend servers in the same AZ as the load balancer, even if some servers are unhealthy. forward_to_healthy_member_of_remote_az: forwards requests across healthy backend servers in different AZs from the load balancer. forward_to_all_healthy_member: forwards requests across healthy backend servers in all AZs. forward_to_all_member: forwards requests across all backend servers in all AZs, even if some servers are unhealthy. The value can be forward_to_all_member_of_local_az, forward_to_healthy_member_of_remote_az, forward_to_all_healthy_member, or forward_to_all_member. Default value: forward_to_all_member_of_local_az

Example Requests¶

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

Example Responses¶

Status code: 200

Successful request.

{
  "pool" : {
    "type" : "",
    "vpc_id" : "",
    "lb_algorithm" : "LEAST_CONNECTIONS",
    "protocol" : "TCP",
    "description" : "My pool",
    "admin_state_up" : true,
    "member_deletion_protection_enable" : false,
    "loadbalancers" : [ {
      "id" : "098b2f68-af1c-41a9-8efd-69958722af62"
    } ],
    "project_id" : "99a3fff0d03c428eac3678da6a7d0f24",
    "session_persistence" : null,
    "healthmonitor_id" : "",
    "listeners" : [ {
      "id" : "0b11747a-b139-492f-9692-2df0b1c87193"
    }, {
      "id" : "61942790-2367-482a-8b0e-93840ea2a1c6"
    }, {
      "id" : "fd8f954c-f0f8-4d39-bb1d-41637cd6b1be"
    } ],
    "members" : [ ],
    "id" : "36ce7086-a496-4666-9064-5ba0e6840c75",
    "name" : "My pool.",
    "ip_version" : "dualstack"
  },
  "request_id" : "c1a60da2-1ec7-4a1c-b4cc-73e1a57b368e"
}

Status Codes¶

Status Code	Description
200	Successful request.

Error Codes¶

See Error Codes.

last updated: 2025-07-21 12:53 UTC - commit: 7edcf7eacf64d408d0a769ee337a358a3f7f6e2b