Viewing the Details of an Active/Standby Backend Server Group

Function

This API is used to view the details of an active/standby backend server group.

Calling Method

For details, see Calling APIs.

URI

GET /v3/{project_id}/elb/master-slave-pools/{pool_id}

**Table 1** Path Parameters
Parameter	Mandatory	Type	Description
project_id	Yes	String	Definition: Specifies the project ID. For details about how to obtain a project ID, see Obtaining a Project ID. Constraints: N/A Range: The value can contain a maximum of 32 characters, including digits and lowercase letters. Default value: N/A
pool_id	Yes	String	Definition: Specifies the backend server group ID. Constraints: N/A Range: N/A Default value: N/A

Request Parameters

**Table 2** Request header parameters
Parameter	Mandatory	Type	Description
X-Auth-Token	Yes	String	Definition: Specifies the token used for IAM authentication. Constraints: N/A Range: N/A Default value: N/A

Response Parameters

Status code: 200

**Table 3** Response body parameters
Parameter	Type	Description
request_id	String	Definition: Specifies the request ID. Range: The value is automatically generated, and can contain characters including digits, lowercase letters, and hyphens (-).
pool	MasterSlavePool object	Definition: Specifies the backend server group.

**Table 4** MasterSlavePool
Parameter	Type	Description
description	String	Definition: Specifies the supplementary information about the backend server group. Range: N/A
id	String	Definition: Specifies the ID of the backend server group. Range: N/A
lb_algorithm	String	Definition: Specifies the load balancing algorithm used by the load balancer to route requests to backend servers in the associated backend server group. Range: ROUND_ROBIN: weighted round robin LEAST_CONNECTIONS: weighted least connections SOURCE_IP: source IP hash QUIC_CID: connection ID
listeners	Array of ListenerRef objects	Definition: Specifies the IDs of the listeners with which the backend server group is associated.
loadbalancers	Array of LoadBalancerRef objects	Definition: Specifies the IDs of the load balancers with which the active/standby backend server group is associated.
members	Array of MasterSlaveMember objects	Definition: Specifies the backend servers in the backend server group.
name	String	Definition: Specifies the backend server group name. Range: N/A
project_id	String	Definition: Specifies the ID of the project where the backend server group is used. Range: N/A
protocol	String	Definition: Specifies the protocol used by the backend server group to receive requests. Range: The value can be TCP, UDP, QUIC, or TLS.
session_persistence	SessionPersistence object	Definition: Specifies the sticky session.
ip_version	String	Definition: Specifies the IP address version supported by the backend server group. 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.
created_at	String	Definition: Specifies the creation time. The value must be a UTC time in the format of yyyy-MM-dd'T'HH:mm:ss'Z'. Range: N/A Note: This parameter 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	Definition: Specifies the update time. The value must be a UTC time in the format of yyyy-MM-dd'T'HH:mm:ss'Z'. Range: N/A Note: This parameter 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	Definition: Specifies the ID of the VPC where the backend server group works. Range: N/A
type	String	Definition: Specifies the backend server group type. Range: 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.
enterprise_project_id	String	Definition: Specifies the ID of the enterprise project. Range: 0: The resource belongs to the default enterprise project. A string in UUID format indicates a non-default enterprise project.
healthmonitor	MasterSlaveHealthMonitor object	Definition: Specifies the health check configured for the active/standby backend server group.
any_port_enable	Boolean	Definition: 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. Range: false (disable this option) or true (enable this option).
connection_drain	ConnectionDrain object	Definition: Specifies the configurations of deregistration delay. 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. Range: N/A
quic_cid_hash_strategy	QuicCidHashStrategy object	Definition: Specifies multi-path distribution configuration based on destination connection IDs.

**Table 5** ListenerRef
Parameter	Type	Description
id	String	Definition: Specifies the listener ID. Range: N/A

**Table 6** LoadBalancerRef
Parameter	Type	Description
id	String	Definition: Specifies the load balancer ID. Range: N/A

**Table 7** MasterSlaveMember
Parameter	Type	Description
id	String	Specifies the backend server ID. Range: N/A
name	String	Definition: Specifies the backend server name. Range: N/A
admin_state_up	Boolean	Definition: 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 ECSs exist. If ECSs exist, the value is true. Otherwise, the value is false. Range: true or false
subnet_cidr_id	String	Specifies the ID of the IPv4 or IPv6 subnet where the backend server works. If ip_target_enable is set to true, this parameter can be left blank, indicating that an IP as backend server will be added. In this case, IP as backend servers must use private IPv4 addresses, and the protocol of the backend server group must be TCP, UDP, TLS, HTTP, HTTPS, QUIC, or GRPC. Range: N/A
protocol_port	Integer	Definition: Specifies the port used by the backend server to receive requests. NOTE: This parameter can be left blank because it does not take effect if any_port_enable is set to true for a backend server group.
address	String	Definition: Specifies the IP address of the backend server Range: N/A
ip_version	String	Definition: Specifies the IP address version supported by the backend server. The version depends on the value of address returned by the system. Range: v4 or v6
device_owner	String	Definition: Specifies whether the backend server is associated with an ECS. Range: If this parameter is left blank, the backend server is not associated with an ECS. If the value is compute:{az_name}, the backend server is associated with an ECS. {az_name} indicates the AZ where the ECS resides. If the value is compute:subeni, supplementary network interfaces are added as backend servers. This parameter is unsupported. Please do not use it.
device_id	String	Definition: Specifies the ID of the ECS with which the backend server is associated. If this parameter is left blank, the backend server is not associated with an ECS. Range: N/A This parameter is unsupported. Please do not use it.
operating_status	String	Definition: Specifies the operating status of the backend server if listener_id under status is not specified. Range: 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.
reason	MemberHealthCheckFailedReason object	Definition: Specifies why the health check fails.
member_type	String	Definition: Specifies the type of the backend server. Range: ip: IP as backend servers instance: ECSs used as backend servers
instance_id	String	Definition: Specifies the ID of the instance associated with the backend server. If this parameter is left blank, the backend server is not a real device. It may be an IP address. Range: N/A
role	String	Definition: Specifies the type of the backend server. Range: N/A
status	Array of ListenerMemberInfo objects	Definition: Specifies the health status of the backend server if listener_id under status is specified. If listener_id under status is not specified, operating_status of member takes precedence. Range: N/A

**Table 8** MemberHealthCheckFailedReason
Parameter	Type	Description
reason_code	String	Definition: Specifies the code of the health check failures. Range: CONNECT_TIMEOUT: The connection with the backend server times out during a health check. CONNECT_REFUSED: The load balancer rejects connections with the backend server during a health check. CONNECT_FAILED: The load balancer fails to establish connections with the backend server during a health check. CONNECT_INTERRUPT: The load balancer is disconnected from the backend server during a health check. SSL_HANDSHAKE_ERROR: The SSL handshakes with the backend server fail during a health check. RECV_RESPONSE_FAILED: The load balancer fails to receive responses from the backend server during a health check. RECV_RESPONSE_TIMEOUT: The load balancer does not receive responses from the backend server within the timeout duration during a health check. SEND_REQUEST_FAILED: The load balancer fails to send a health check request to the backend server during a health check. SEND_REQUEST_TIMEOUT: The load balancer fails to send a health check request to the backend server within the timeout duration. RESPONSE_FORMAT_ERROR: The load balancer receives invalid responses from the backend server during a health check. RESPONSE_MISMATCH: The response code received from the backend server is different from the preset code.
expected_response	String	Definition: Specifies the expected HTTP status code. This parameter will take effect only when type is set to HTTP, HTTPS, or GRPC. The status code cannot be null if reason_code is RESPONSE_MISMATCH. Range: A specific status code. If type is set to GRPC, the status code ranges from 0 to 99. If type is set to other values, the status code ranges from 200 to 599. For example, the status code can be 0 or 200. A list of status codes that are separated with commas (,), for example, 200,202 or 0,1. A maximum of five status codes are supported. A status code range. Different ranges are separated with commas (,), for example, 200-204,300-399 or 0-5,10-12,20-30. A maximum of five ranges are supported.
healthcheck_response	String	Definition: Specifies the returned HTTP status code in the response. This parameter will take effect only when type is set to HTTP, HTTPS, or GRPC. The status code cannot be null if reason_code is RESPONSE_MISMATCH. Range: A specific status code. If type is set to GRPC, the status code ranges from 0 to 99. If type is set to other values, the status code ranges from 200 to 599. For example, the status code can be 0 or 200.

**Table 9** ListenerMemberInfo
Parameter	Type	Description
listener_id	String	Definition: Specifies the ID of the listener associated with the backend server. Range: N/A
operating_status	String	Definition: Specifies the operating status of the backend server. Range: 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 10** SessionPersistence
Parameter	Type	Description
cookie_name	String	Definition: Specifies the cookie name. Range: The value can contain a maximum of 1,024 characters.
type	String	Definition: Specifies the sticky session type. Range: SOURCE_IP, HTTP_COOKIE, or APP_COOKIE.
persistence_timeout	Integer	Definition: Specifies the stickiness duration, in minutes. This parameter will not take effect when type is set to APP_COOKIE. Range: 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 11** MasterSlaveHealthMonitor
Parameter	Type	Description
admin_state_up	Boolean	Definition: Specifies the administrative status of the health check. Range: true: The health check function is enabled. false: The health check function is disabled.
delay	Integer	Definition: Specifies the interval between health checks, in seconds. Range: 1 to 50
domain_name	String	Definition: Specifies the domain name that HTTP requests are sent to during the health check. Range: The value can contain only digits, letters, hyphens (-), and periods (.) and must start with a digit or letter.
expected_codes	String	Definition: Specifies the expected HTTP status code. Range: A specific value, for example, 200 A list of values that are separated with commas (,), for example, 200, 202 A value range, for example, 200-204
http_method	String	Definition: Specifies the HTTP method. Range: GET, HEAD, or POST
id	String	Specifies the health check ID. Default value: N/A
max_retries	Integer	Definition: Specifies the number of consecutive health checks when the health check result of a backend server changes from OFFLINE to ONLINE. Range: 1 to 10
max_retries_down	Integer	Definition: Specifies the number of consecutive health checks when the health check result of a backend server changes from ONLINE to OFFLINE. Range: 1 to 10
monitor_port	Integer	Specifies the port used for the health check. Range: 1 to 65535
name	String	Definition: Specifies the health check name. Range: N/A
timeout	Integer	Definition: Specifies the maximum time required for waiting for a response from the health check, in seconds. Range: N/A
type	String	Definition: Specifies the health check protocol. Range: The value can be TCP, UDP_CONNECT, HTTP, or HTTPS.
url_path	String	Definition: Specifies the HTTP request path for the health check. The value must start with a slash (/), and the default value is /. Range: The value can contain letters, digits, hyphens (-), slashes (/), periods (.), percentage signs (%), question marks (?), pound signs (#), ampersand signs (&), and the extended character set: _;~!()*[]@$^:',+.

**Table 12** ConnectionDrain
Parameter	Type	Description
enable	Boolean	Definition: Specifies whether to enable connection_drain. Constraints: N/A Range: The value can be true (enable this option) or false (disable this option). Default value: N/A
timeout	Integer	Definition: Specifies the deregistration delay timeout, in seconds. Constraints: N/A Range: 10 to 4000, in seconds. Constraints: N/A

**Table 13** QuicCidHashStrategy
Parameter	Type	Description
len	Integer	Definition: Specifies the length of the hash factor in the connection ID. Constraints: This parameter is valid only when the load balancing algorithm is QUIC_CID. Range: 1 to 20 Default value: 3
offset	Integer	Definition: Specifies the start position in the connection ID as the hash factor. Constraints: This parameter is valid only when the load balancing algorithm is QUIC_CID. Range: 0 to 19 Default value: 1

Example Requests

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

Example Responses

Status code: 200

Successful request.

{
  "pool" : {
    "lb_algorithm" : "LEAST_CONNECTIONS",
    "type" : "ip",
    "vpc_id" : "3sae7086-a416-4666-9064-5b340e6840125",
    "protocol" : "TCP",
    "description" : "",
    "loadbalancers" : [ {
      "id" : "098b2f68-af1c-41a9-8efd-69958722af62"
    } ],
    "project_id" : "99a3fff0d03c428eac3678da6a7d0f24",
    "session_persistence" : null,
    "healthmonitor" : {
      "monitor_port" : null,
      "id" : "36ce7086-a496-4666-9064-5ba0e6840c75",
      "domain_name" : "",
      "name" : "My Healthmonitor",
      "max_retries" : 3,
      "max_retries_down" : 3,
      "admin_state_up" : true,
      "type" : "HTTP",
      "timeout" : 30,
      "delay" : 1,
      "http_method" : "get",
      "url_path" : "/",
      "expected_codes" : "200"
    },
    "listeners" : [ {
      "id" : "0b11747a-b139-492f-9692-2df0b1c87193"
    } ],
    "members" : [ {
      "admin_state_up" : true,
      "address" : "172.16.0.210",
      "protocol_port" : 80,
      "id" : "2e7b36d2-66c8-4825-bcd2-211d99978680",
      "operating_status" : "OFFLINE",
      "status" : [ ],
      "instance_id" : "",
      "device_id" : "",
      "device_owner" : "",
      "member_type" : "ip",
      "role" : "master",
      "ip_version" : "v4",
      "name" : "cx-test-master",
      "subnet_cidr_id" : ""
    }, {
      "admin_state_up" : true,
      "address" : "172.16.0.211",
      "protocol_port" : 81,
      "id" : "2e7b36d2-66c8-4823-bsd2-21sa199978681",
      "operating_status" : "OFFLINE",
      "status" : [ ],
      "instance_id" : "",
      "device_id" : "",
      "device_owner" : "",
      "member_type" : "ip",
      "role" : "slave",
      "ip_version" : "v4",
      "name" : "cx-test-slave",
      "subnet_cidr_id" : ""
    } ],
    "id" : "36ce7086-a496-4666-9064-5ba0e6840c75",
    "name" : "My pool",
    "ip_version" : "dualstack",
    "created_at" : "2021-03-26T01:33:12Z",
    "updated_at" : "2021-03-26T01:33:12Z"
  },
  "request_id" : "c1a60da2-1ec7-4a1c-b4cc-73e1a57b368e"
}

SDK Sample Code

The SDK sample code is as follows.

      
       
         
         
           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 ShowMasterSlavePoolSolution {

    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();
        ShowMasterSlavePoolRequest request = new ShowMasterSlavePoolRequest();
        request.withPoolId("{pool_id}");
        try {
            ShowMasterSlavePoolResponse response = client.showMasterSlavePool(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 = ShowMasterSlavePoolRequest()
        request.pool_id = "{pool_id}"
        response = client.show_master_slave_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.ShowMasterSlavePoolRequest{}
	request.PoolId = "{pool_id}"
	response, err := client.ShowMasterSlavePool(request)
	if err == nil {
        fmt.Printf("%+v\n", response)
    } else {
        fmt.Println(err)
    }
}

          

        

      
     