Updated on 2024-04-09 GMT+08:00

Querying Backend Server Groups

Function

This API is used to query all backend server groups.

Constraints

This API has the following constraints:

  • Parameters marker, limit, and page_reverse are used for pagination query.

  • Parameters marker and page_reverse take effect only when they are used together with parameter limit.

Calling Method

For details, see Calling APIs.

URI

GET /v3/{project_id}/elb/pools

Table 1 Path Parameters

Parameter

Mandatory

Type

Description

project_id

Yes

String

Specifies the project ID.

Table 2 Query Parameters

Parameter

Mandatory

Type

Description

marker

No

String

Specifies the ID of the last record on the previous page.

Note:

  • This parameter must be used together with limit.

  • If this parameter is not specified, the first page will be queried.

  • This parameter cannot be left blank or set to an invalid ID.

limit

No

Integer

Specifies the number of records on each page.

Minimum: 0

Maximum: 2000

Default: 2000

page_reverse

No

Boolean

Specifies whether to use reverse query. Values:

  • true: Query the previous page.

  • false (default): Query the next page.

Note:

  • This parameter must be used together with limit.

  • If page_reverse is set to true and you want to query the previous page, set the value of marker to the value of previous_marker.

description

No

Array

Provides supplementary information about the backend server group.

Multiple descriptions can be queried in the format of description=xxx&description=xxx.

admin_state_up

No

Boolean

Specifies the administrative status of the backend server group.

This parameter is unsupported. Please do not use it.

healthmonitor_id

No

Array

Specifies the ID of the health check configured for the backend server group.

Multiple IDs can be queried in the format of healthmonitor_id=xxx&healthmonitor_id=xxx.

id

No

Array

Specifies the ID of the backend server group.

Multiple IDs can be queried in the format of id=xxx&id=xxx.

name

No

Array

Specifies the backend server group name.

Multiple names can be queried in the format of name=xxx&name=xxx.

loadbalancer_id

No

Array

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

Multiple IDs can be queried in the format of loadbalancer_id=xxx&loadbalancer_id=xxx.

protocol

No

Array

Specifies the protocol used by the backend server group to receive requests from the load balancer. The value can be TCP, UDP, HTTP, HTTPS, QUIC, or TLS.

Multiple protocols can be queried in the format of protocol=xxx&protocol=xxx.

lb_algorithm

No

Array

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

Multiple algorithms can be queried in the format of lb_algorithm=xxx&lb_algorithm=xxx.

enterprise_project_id

No

Array

Specifies the enterprise project ID.

  • If this parameter is not passed, resources in the default enterprise project are queried, and authentication is performed based on the default enterprise project.

  • If this parameter is passed, its value can be the ID of an existing enterprise project (resources in the specific enterprise project are required) or all_granted_eps (resources in all enterprise projects are queried).

Multiple IDs can be queried in the format of enterprise_project_id=xxx&enterprise_project_id=xxx.

ip_version

No

Array

Specifies the IP address version supported by the backend server group.

Multiple versions can be queried in the format of ip_version=xxx&ip_version=xxx.

member_address

No

Array

Specifies the private IP address bound to the backend server. This is a query parameter and will not be included in the response.

Multiple IP addresses can be queried in the format of member_address=xxx&member_address=xxx.

member_device_id

No

Array

Specifies the ID of the cloud server that serves as a backend server. This parameter is used only as a query condition and is not included in the response.

Multiple IDs can be queried in the format of member_device_id=xxx&member_device_id=xxx.

member_deletion_protection_enable

No

Boolean

Specifies whether to enable deletion protection.

  • true: Enable deletion protection.

  • false: Disable deletion protection.

listener_id

No

Array

Specifies the IDs of the associated listeners, including the listeners associated through forwarding policies.

Multiple IDs can be queried in the format of listener_id=xxx&listener_id=xxx.

member_instance_id

No

Array

Specifies the backend server ID. This parameter is used only as a query condition and is not included in the response. Multiple IDs can be queried in the format of member_instance_id=xxx&member_instance_id=xxx.

vpc_id

No

Array

Specifies the ID of the VPC where the backend server group works.

type

No

Array

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.

pool_health

No

String

This API is used to query whether pool_health is enabled. If minimum_healthy_member_count is 0, pool_health is disabled. If minimum_healthy_member_count is 1, pool_health is enabled.

Request Parameters

Table 3 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 4 Response body parameters

Parameter

Type

Description

request_id

String

Specifies the request ID. The value is automatically generated.

page_info

PageInfo object

Shows pagination information.

pools

Array of Pool objects

Lists the backend server groups.

Table 5 PageInfo

Parameter

Type

Description

previous_marker

String

Specifies the ID of the first record in the pagination query result.

next_marker

String

Specifies the ID of the last record in the pagination query result.

current_count

Integer

Specifies the number of records.

Table 6 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

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  • 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, QUIC, or TLS.

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 or HTTPS.

  • If the listener's protocol is TERMINATED_HTTPS, the protocol of the backend server group must be HTTP.

  • If the protocol of the backend server group is QUIC, session_persistence must be enabled and type must be 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.

  • 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, UDP, or QUIC, the value is dualstack. If the protocol of the backend server group is HTTP or HTTPS, 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.

  • 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 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.

enterprise_project_id

String

Specifies the enterprise project ID of the IP address group.

pool_health

PoolHealth object

Specifies the configurations of the pool health feature.

Table 7 ListenerRef

Parameter

Type

Description

id

String

Specifies the listener ID.

Table 8 LoadBalancerRef

Parameter

Type

Description

id

String

Specifies the load balancer ID.

Table 9 MemberRef

Parameter

Type

Description

id

String

Specifies the backend server ID.

Table 10 SessionPersistence

Parameter

Type

Description

cookie_name

String

Specifies the cookie name.

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 (.).

Note:

This parameter will take effect only when type is set to APP_COOKIE. Otherwise, an error will be returned.

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 11 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 12 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).

Example Requests

Querying backend server groups

GET https://{ELB_Endpoint}/v3/99a3fff0d03c428eac3678da6a7d0f24/elb/pools?limit=2

Example Responses

Status code: 200

Successful request.

{
  "pools" : [ {
    "lb_algorithm" : "ROUND_ROBIN",
    "protocol" : "HTTP",
    "type" : "",
    "vpc_id" : "",
    "description" : "",
    "admin_state_up" : true,
    "member_deletion_protection_enable" : false,
    "loadbalancers" : [ {
      "id" : "309a0f61-0b62-45f2-97d1-742f3434338e"
    } ],
    "project_id" : "99a3fff0d03c428eac3678da6a7d0f24",
    "session_persistence" : {
      "cookie_name" : "my_cookie",
      "type" : "APP_COOKIE",
      "persistence_timeout" : 1
    },
    "healthmonitor_id" : "",
    "listeners" : [ ],
    "members" : [ ],
    "id" : "73bd4fe0-ffbb-4b56-aab4-4f26ddf7a103",
    "name" : "",
    "ip_version" : "v4",
    "pool_health" : {
      "minimum_healthy_member_count" : 0
    }
  }, {
    "lb_algorithm" : "SOURCE_IP",
    "protocol" : "TCP",
    "description" : "",
    "admin_state_up" : true,
    "member_deletion_protection_enable" : false,
    "loadbalancers" : [ {
      "id" : "d9763e59-64b7-4e93-aec7-0ff7881ef9bc"
    } ],
    "project_id" : "99a3fff0d03c428eac3678da6a7d0f24",
    "session_persistence" : {
      "cookie_name" : "",
      "type" : "SOURCE_IP",
      "persistence_timeout" : 1
    },
    "healthmonitor_id" : "",
    "listeners" : [ {
      "id" : "8d21db6f-b475-429e-a9cb-90439b0413b2"
    } ],
    "members" : [ ],
    "id" : "74db02d1-5711-4c77-b383-a450e2b93142",
    "name" : "pool_tcp_001",
    "ip_version" : "dualstack",
    "pool_health" : {
      "minimum_healthy_member_count" : 0
    }
  } ],
  "page_info" : {
    "next_marker" : "74db02d1-5711-4c77-b383-a450e2b93142",
    "previous_marker" : "73bd4fe0-ffbb-4b56-aab4-4f26ddf7a103",
    "current_count" : 2
  },
  "request_id" : "a1a7e852-1928-48f7-bbc9-ca8469898713"
}

Status Codes

Status Code

Description

200

Successful request.

Error Codes

See Error Codes.