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Help Center/ Elastic Load Balance/ API Reference/ APIs (V3)/ Backend Server Group/ Querying the Details of a Backend Server Group

Querying the Details of a Backend Server Group

Updated on 2025-02-25 GMT+08:00

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Function

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

Calling Method

For details, see Calling APIs.

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. Note: 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.
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. Value options: ROUND_ROBIN: weighted round robin LEAST_CONNECTIONS: weighted least connections SOURCE_IP: source IP hash QUIC_CID: connection ID
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, TLS, HTTP, HTTPS, GRPC, or QUIC. Note: If the listener's protocol is UDP, the protocol of the backend server group must be UDP or QUIC. 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, HTTPS, or GRPC. If the listener's protocol is TERMINATED_HTTPS, the protocol of the backend server group must be HTTP. If the listener's protocol is QUIC, the protocol of the backend server group can be HTTP, HTTPS, or GRPC. If the listener's protocol is TLS, the protocol of the backend server group can be TLS or TCP. If protocol of the backend server group is TCP, the ip_version must be set to v4. Note: If protocol of the backend server group is QUIC, session_persistence must be set to true, with type set to SOURCE_IP. If protocol of the backend server group is GRPC, http2_enable of the listener must be set to true.
session_persistence	SessionPersistence object	Specifies the sticky session.
ip_version	String	Specifies the IP address version supported by the backend server group. Value range: Shared load balancers: The value is fixed at v4. Dedicated load balancers: The value can be dualstack or v4. If the protocol of the backend server group is TCP or UDP, the value is dualstack. If the protocol of the backend server group is HTTP, the value is v4.
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 deletion protection. Value options: true: Enable deletion protection. false: Disable deletion protection. NOTE: Disable deletion protection for all your resources before deleting your account.
created_at	String	Specifies the time when the 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 the 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. Value options: 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 (<>).
any_port_enable	Boolean	Specifies whether to enable any_port_enable for a backend server group. If this option is enabled, the listener routes the requests to the backend server over the same port as the frontend port. If this option is disabled, the listener routes the requests over the port specified by protocol_port. Value options: false: Disable this option. true: Enable this option. Note: This option is available only for TCP, UDP, or QUIC backend server groups.
connection_drain	ConnectionDrain object	Specifies the configurations of deregistration delay. This parameter is only available for TCP, UDP, and QUIC backend server groups and TCP and UDP listeners. This parameter takes effect when: A backend server is removed from a backend server group. A backend server is detected unhealthy or health checks fail. The weight of a backend server is 0.
enterprise_project_id	String	Specifies the ID of the enterprise project that the IP address group belongs to.
pool_health	PoolHealth object	Specifies the configurations of the pool health feature.
public_border_group	String	Specifies the public border group, for example, center.
quic_cid_hash_strategy	QuicCidHashStrategy object	Specifies multi-path forwarding policy based on destination connection IDs.

**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. Note: This parameter will take effect only when type is set to APP_COOKIE. Otherwise, an error will be returned. Value ranges: For shared load balancers, the name can contain a maximum of 64 characters, including letters, digits, underscores (_), and hyphens (-). For dedicated load balancers, the name can contain a maximum of 255 characters, including letters, digits, underscores (_), hyphens (-), and periods (.).
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. If the protocol of the backend server group is HTTP or HTTPS, the value can be HTTP_COOKIE or APP_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 (default): Disable slow start.
duration	Integer	Specifies the slow start duration, in seconds. The value ranges from 30 to 1200, and the default value is 30.

**Table 10** ConnectionDrain
Parameter	Type	Description
enable	Boolean	Specifies whether to enable connection_drain. Value options: true: Enable this option. false: Disable this option. Default value: true
timeout	Integer	Specifies the deregistration delay timeout, in seconds. The value ranges from 10 to 4000.

**Table 11** PoolHealth
Parameter	Type	Description
minimum_healthy_member_count	Integer	If the number of healthy backend servers is less than the value specified for this parameter, the backend server group is considered as unhealthy. The value can be 0 (disabled) or 1 (enabled).

**Table 12** QuicCidHashStrategy
Parameter	Type	Description
len	Integer	Specifies the length of the hash factor in the connection ID, in byte. This parameter is valid only when the load balancing algorithm is QUIC_CID. Value range: 1 to 20 Default value: 3
offset	Integer	Specifies the start position in the connection ID as the hash factor, in byte. This parameter is valid only when the load balancing algorithm is QUIC_CID. Value range: 0 to 19 Default value: 1

Example Requests

Querying the details of a backend server group

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",
    "pool_health" : {
      "minimum_healthy_member_count" : 0
    }
  },
  "request_id" : "c1a60da2-1ec7-4a1c-b4cc-73e1a57b368e"
}

SDK Sample Code

The SDK sample code is as follows.

Java
Python
Go
More

      
       
         
         package com.huaweicloud.sdk.test;

import com.huaweicloud.sdk.core.auth.ICredential;
import com.huaweicloud.sdk.core.auth.BasicCredentials;
import com.huaweicloud.sdk.core.exception.ConnectionException;
import com.huaweicloud.sdk.core.exception.RequestTimeoutException;
import com.huaweicloud.sdk.core.exception.ServiceResponseException;
import com.huaweicloud.sdk.elb.v3.region.ElbRegion;
import com.huaweicloud.sdk.elb.v3.*;
import com.huaweicloud.sdk.elb.v3.model.*;


public class ShowPoolSolution {

    public static void main(String[] args) {
        // The AK and SK used for authentication are hard-coded or stored in plaintext, which has great security risks. It is recommended that the AK and SK be stored in ciphertext in configuration files or environment variables and decrypted during use to ensure security.
        // In this example, AK and SK are stored in environment variables for authentication. Before running this example, set environment variables CLOUD_SDK_AK and CLOUD_SDK_SK in the local environment
        String ak = System.getenv("CLOUD_SDK_AK");
        String sk = System.getenv("CLOUD_SDK_SK");
        String projectId = "{project_id}";

        ICredential auth = new BasicCredentials()
                .withProjectId(projectId)
                .withAk(ak)
                .withSk(sk);

        ElbClient client = ElbClient.newBuilder()
                .withCredential(auth)
                .withRegion(ElbRegion.valueOf("<YOUR REGION>"))
                .build();
        ShowPoolRequest request = new ShowPoolRequest();
        request.withPoolId("{pool_id}");
        try {
            ShowPoolResponse response = client.showPool(request);
            System.out.println(response.toString());
        } catch (ConnectionException e) {
            e.printStackTrace();
        } catch (RequestTimeoutException e) {
            e.printStackTrace();
        } catch (ServiceResponseException e) {
            e.printStackTrace();
            System.out.println(e.getHttpStatusCode());
            System.out.println(e.getRequestId());
            System.out.println(e.getErrorCode());
            System.out.println(e.getErrorMsg());
        }
    }
}

        

      
     

      
       
         
         # coding: utf-8

import os
from huaweicloudsdkcore.auth.credentials import BasicCredentials
from huaweicloudsdkelb.v3.region.elb_region import ElbRegion
from huaweicloudsdkcore.exceptions import exceptions
from huaweicloudsdkelb.v3 import *

if __name__ == "__main__":
    # The AK and SK used for authentication are hard-coded or stored in plaintext, which has great security risks. It is recommended that the AK and SK be stored in ciphertext in configuration files or environment variables and decrypted during use to ensure security.
    # In this example, AK and SK are stored in environment variables for authentication. Before running this example, set environment variables CLOUD_SDK_AK and CLOUD_SDK_SK in the local environment
    ak = os.environ["CLOUD_SDK_AK"]
    sk = os.environ["CLOUD_SDK_SK"]
    projectId = "{project_id}"

    credentials = BasicCredentials(ak, sk, projectId)

    client = ElbClient.new_builder() \
        .with_credentials(credentials) \
        .with_region(ElbRegion.value_of("<YOUR REGION>")) \
        .build()

    try:
        request = ShowPoolRequest()
        request.pool_id = "{pool_id}"
        response = client.show_pool(request)
        print(response)
    except exceptions.ClientRequestException as e:
        print(e.status_code)
        print(e.request_id)
        print(e.error_code)
        print(e.error_msg)

        

      
     

      
       
         
         package main

import (
	"fmt"
	"github.com/huaweicloud/huaweicloud-sdk-go-v3/core/auth/basic"
    elb "github.com/huaweicloud/huaweicloud-sdk-go-v3/services/elb/v3"
	"github.com/huaweicloud/huaweicloud-sdk-go-v3/services/elb/v3/model"
    region "github.com/huaweicloud/huaweicloud-sdk-go-v3/services/elb/v3/region"
)

func main() {
    // The AK and SK used for authentication are hard-coded or stored in plaintext, which has great security risks. It is recommended that the AK and SK be stored in ciphertext in configuration files or environment variables and decrypted during use to ensure security.
    // In this example, AK and SK are stored in environment variables for authentication. Before running this example, set environment variables CLOUD_SDK_AK and CLOUD_SDK_SK in the local environment
    ak := os.Getenv("CLOUD_SDK_AK")
    sk := os.Getenv("CLOUD_SDK_SK")
    projectId := "{project_id}"

    auth := basic.NewCredentialsBuilder().
        WithAk(ak).
        WithSk(sk).
        WithProjectId(projectId).
        Build()

    client := elb.NewElbClient(
        elb.ElbClientBuilder().
            WithRegion(region.ValueOf("<YOUR REGION>")).
            WithCredential(auth).
            Build())

    request := &model.ShowPoolRequest{}
	request.PoolId = "{pool_id}"
	response, err := client.ShowPool(request)
	if err == nil {
        fmt.Printf("%+v\n", response)
    } else {
        fmt.Println(err)
    }
}

        

      
     

For SDK sample code of more programming languages, see the Sample Code tab in API Explorer. SDK sample code can be automatically generated.

      
       
         
         package com.huaweicloud.sdk.test;

import com.huaweicloud.sdk.core.auth.ICredential;
import com.huaweicloud.sdk.core.auth.BasicCredentials;
import com.huaweicloud.sdk.core.exception.ConnectionException;
import com.huaweicloud.sdk.core.exception.RequestTimeoutException;
import com.huaweicloud.sdk.core.exception.ServiceResponseException;
import com.huaweicloud.sdk.elb.v3.region.ElbRegion;
import com.huaweicloud.sdk.elb.v3.*;
import com.huaweicloud.sdk.elb.v3.model.*;


public class ShowPoolSolution {

    public static void main(String[] args) {
        // The AK and SK used for authentication are hard-coded or stored in plaintext, which has great security risks. It is recommended that the AK and SK be stored in ciphertext in configuration files or environment variables and decrypted during use to ensure security.
        // In this example, AK and SK are stored in environment variables for authentication. Before running this example, set environment variables CLOUD_SDK_AK and CLOUD_SDK_SK in the local environment
        String ak = System.getenv("CLOUD_SDK_AK");
        String sk = System.getenv("CLOUD_SDK_SK");
        String projectId = "{project_id}";

        ICredential auth = new BasicCredentials()
                .withProjectId(projectId)
                .withAk(ak)
                .withSk(sk);

        ElbClient client = ElbClient.newBuilder()
                .withCredential(auth)
                .withRegion(ElbRegion.valueOf("<YOUR REGION>"))
                .build();
        ShowPoolRequest request = new ShowPoolRequest();
        request.withPoolId("{pool_id}");
        try {
            ShowPoolResponse response = client.showPool(request);
            System.out.println(response.toString());
        } catch (ConnectionException e) {
            e.printStackTrace();
        } catch (RequestTimeoutException e) {
            e.printStackTrace();
        } catch (ServiceResponseException e) {
            e.printStackTrace();
            System.out.println(e.getHttpStatusCode());
            System.out.println(e.getRequestId());
            System.out.println(e.getErrorCode());
            System.out.println(e.getErrorMsg());
        }
    }
}

        

      
     

      
       
         
         # coding: utf-8

import os
from huaweicloudsdkcore.auth.credentials import BasicCredentials
from huaweicloudsdkelb.v3.region.elb_region import ElbRegion
from huaweicloudsdkcore.exceptions import exceptions
from huaweicloudsdkelb.v3 import *

if __name__ == "__main__":
    # The AK and SK used for authentication are hard-coded or stored in plaintext, which has great security risks. It is recommended that the AK and SK be stored in ciphertext in configuration files or environment variables and decrypted during use to ensure security.
    # In this example, AK and SK are stored in environment variables for authentication. Before running this example, set environment variables CLOUD_SDK_AK and CLOUD_SDK_SK in the local environment
    ak = os.environ["CLOUD_SDK_AK"]
    sk = os.environ["CLOUD_SDK_SK"]
    projectId = "{project_id}"

    credentials = BasicCredentials(ak, sk, projectId)

    client = ElbClient.new_builder() \
        .with_credentials(credentials) \
        .with_region(ElbRegion.value_of("<YOUR REGION>")) \
        .build()

    try:
        request = ShowPoolRequest()
        request.pool_id = "{pool_id}"
        response = client.show_pool(request)
        print(response)
    except exceptions.ClientRequestException as e:
        print(e.status_code)
        print(e.request_id)
        print(e.error_code)
        print(e.error_msg)

        

      
     

      
       
         
         package main

import (
	"fmt"
	"github.com/huaweicloud/huaweicloud-sdk-go-v3/core/auth/basic"
    elb "github.com/huaweicloud/huaweicloud-sdk-go-v3/services/elb/v3"
	"github.com/huaweicloud/huaweicloud-sdk-go-v3/services/elb/v3/model"
    region "github.com/huaweicloud/huaweicloud-sdk-go-v3/services/elb/v3/region"
)

func main() {
    // The AK and SK used for authentication are hard-coded or stored in plaintext, which has great security risks. It is recommended that the AK and SK be stored in ciphertext in configuration files or environment variables and decrypted during use to ensure security.
    // In this example, AK and SK are stored in environment variables for authentication. Before running this example, set environment variables CLOUD_SDK_AK and CLOUD_SDK_SK in the local environment
    ak := os.Getenv("CLOUD_SDK_AK")
    sk := os.Getenv("CLOUD_SDK_SK")
    projectId := "{project_id}"

    auth := basic.NewCredentialsBuilder().
        WithAk(ak).
        WithSk(sk).
        WithProjectId(projectId).
        Build()

    client := elb.NewElbClient(
        elb.ElbClientBuilder().
            WithRegion(region.ValueOf("<YOUR REGION>")).
            WithCredential(auth).
            Build())

    request := &model.ShowPoolRequest{}
	request.PoolId = "{pool_id}"
	response, err := client.ShowPool(request)
	if err == nil {
        fmt.Printf("%+v\n", response)
    } else {
        fmt.Println(err)
    }
}

        

      
     

For SDK sample code of more programming languages, see the Sample Code tab in API Explorer. SDK sample code can be automatically generated.

Status Codes

Status Code	Description
200	Successful request.

Error Codes

See Error Codes.

Parent Topic: Backend Server Group

Previous topic: Querying Backend Server Groups

Next topic: Updating a Backend Server Group

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