Querying Backend Server Groups

Function

This API is used to query the backend server groups and display them in a list. Filter query and pagination query are supported. Unless otherwise specified, exact match is applied.

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.

URI

GET /v2.0/lbaas/pools

Request

**Table 1** Parameter description
Parameter	Mandatory	Type	Description
marker	No	String	Specifies the ID of the backend server group from which pagination query starts, that is, the ID of the last backend server group on the previous page. If this parameter is not specified, the first page will be queried. This parameter must be used together with limit.
limit	No	Integer	Specifies the number of backend server groups on each page.
page_reverse	No	Boolean	Specifies the page direction. The value can be true or false, and the default value is false. The last page in the list requested with page_reverse set to false will not contain the "next" link, and the last page in the list requested with page_reverse set to true will not contain the "previous" link. This parameter must be used together with limit.
id	No	String	Specifies the ID of the backend server group.
tenant_id	No	String	Specifies the ID of the project where the backend server group is used. The value contains a maximum of 255 characters.
name	No	String	Specifies the name of the backend server group. The value contains a maximum of 255 characters.
description	No	String	Provides supplementary information about the backend server group. The value contains a maximum of 255 characters.
healthmonitor_id	No	String	Specifies the ID of the health check configured for the backend server group.
loadbalancer_id	No	String	Specifies the ID of the load balancer associated with the backend server group.
protocol	No	String	Specifies the protocol that the backend server group uses to receive requests. TCP, UDP, and HTTP are supported.
lb_algorithm	No	String	Specifies the load balancing algorithm of the backend server group. The value can be one of the following: ROUND_ROBIN: indicates the weighted round robin algorithm. LEAST_CONNECTIONS: indicates the weighted least connections algorithm. SOURCE_IP: indicates the source IP hash algorithm. When the value is SOURCE_IP, the weights of backend servers in the server group are invalid. For details about parameter weight, see Table 2.
member_address	No	String	Lists the IDs of backend servers in the backend server group.
member_device_id	No	String	Specifies the ID of the cloud server used as the backend server in the backend server group.

Response

**Table 2** Response parameters
Parameter	Type	Description
pools	Array	Specifies the backend server group. For details, see Table 3.
pools_links	List	Provides links to the previous or next page during pagination query, respectively. This parameter exists only in the response body of pagination query. For details, see Table 8.

**Table 3** **pools** parameter description
Parameter	Type	Description
id	String	Specifies the ID of the backend server group.
tenant_id	String	Specifies the ID of the project where the backend server group is used. The value contains a maximum of 255 characters.
name	String	Specifies the name of the backend server group. The value contains a maximum of 255 characters.
description	String	Provides supplementary information about the backend server group. The value contains a maximum of 255 characters.
protocol	String	Specifies the protocol that the backend server group uses to receive requests. TCP, UDP, and HTTP are supported.
lb_algorithm	String	Specifies the load balancing algorithm of the backend server group. The value can be one of the following: ROUND_ROBIN: indicates the weighted round robin algorithm. LEAST_CONNECTIONS: indicates the weighted least connections algorithm. SOURCE_IP: indicates the source IP hash algorithm. When the value is SOURCE_IP, the weights of backend servers in the server group are invalid.
members	Array	Lists the IDs of backend servers in the backend server group.
healthmonitor_id	String	Specifies the ID of the health check configured for the backend server group.
admin_state_up	Boolean	Specifies the administrative status of the backend server group. This parameter is reserved. The value can be true or false. true: Enabled false: Disabled
listeners	Array	Lists the IDs of listeners associated with the backend server group.
loadbalancers	String	Lists the IDs of load balancers associated with the backend server group.
session_persistence	Object	Specifies whether to enable the sticky session feature. For details, see Table 7. Once sticky session are enabled, requests from the same client are sent to the same backend server during the session. When sticky sessions are disabled, the value is null.

**Table 4** **members** parameter description
Parameter	Type	Description
id	String	Specifies the ID of the associated backend server.

**Table 5** **listeners** parameter description
Parameter	Type	Description
id	String	Specifies the ID of the associated backend server group.

**Table 6** **loadbalancers** parameter description
Parameter	Type	Description
id	String	Specifies the ID of the associated load balancer.

**Table 7** **session_persistence** parameter description
Parameter	Type	Description
type	String	Specifies the sticky session type. The value can be one of the following: SOURCE_IP: Requests are distributed based on the client's IP address. Requests from the same IP address are sent to the same backend server. HTTP_COOKIE: When the client sends a request for the first time, the load balancer automatically generates a cookie and inserts the cookie into the response message. Subsequent requests are sent to the backend server that processes the first request. APP_COOKIE: When the client sends a request for the first time, the backend server that receives the request generates a cookie and inserts the cookie into the response message. Subsequent requests are sent to this backend server. When the protocol of the backend server group is TCP, only SOURCE_IP takes effect. When the protocol of the backend server group is HTTP, only HTTP_COOKIE or APP_COOKIE takes effect.
cookie_name	String	Specifies the cookie name. This parameter is mandatory when the sticky session type is APP_COOKIE.
persistence_timeout	Integer	Specifies the sticky session timeout duration in minutes. This parameter is invalid when type is set to APP_COOKIE. Optional value ranges are as follows: When the protocol of the backend server group is TCP or UDP, the value ranges from 1 to 60. When the protocol of the backend server group is HTTP or HTTPS, the value ranges from 1 to 1440.

**Table 8** **pools_links** parameter description
Parameter	Type	Description
href	String	Provides links to the previous or next page during pagination query, respectively.
rel	String	Specifies the prompt of the previous or next page. The value can be next or previous. next: indicates the URL of the next page. previous: indicates the URL of the previous page.

Example Request

Example request 1: Querying backend server groups by pages
```
GET https://{Endpoint}/v2.0/lbaas/pools?limit=2
```
Example request 2: Querying backend server groups whose load balancing algorithm is SOURCE_IP
```
GET https://{Endpoint}/v2.0/lbaas/pools?lb_algorithm=SOURCE_IP
```

Example Response

Example response 1

{
    "pools": [
        {
            "lb_algorithm": "SOURCE_IP",
            "protocol": "TCP",
            "description": "",
            "admin_state_up": true,
            "loadbalancers": [
                {
                    "id": "07d28d4a-4899-40a3-a939-5d09d69019e1"
                }
            ],
            "tenant_id": "1867112d054b427e808cc6096d8193a1",
 
            "session_persistence": null,
            "healthmonitor_id": null,
            "listeners": [
                {
                    "id": "1b421c2d-7e78-4a78-9ee4-c8ccba41f15b"
                }
            ],
            "members": [
                {
                    "id": "88f9c079-29cb-435a-b98f-0c5c0b90c2bd"
                },
                {
                    "id": "2f4c9644-d5d2-4cf8-a3c0-944239a4f58c"
                }
            ],
            "id": "3a9f50bb-f041-4eac-a117-82472d8a0007",
            "name": "my-pool"
        }
    ],
    "pools_links": [
        {
        "href": "https://{Endpoint}/v2.0/lbaas/pools?limit=2&marker=0469a5ad-6233-4669-8d38-5920f2bd95b6",
        "rel": "next"
        },
        {
        "href": "https://{Endpoint}/v2.0/lbaas/pools?limit=2&marker=02d43e35-e874-4139-bdba-d65609db20ab&page_reverse=True",
        "rel": "previous"
        }
    ]
}

Example response 2

{
    "pools": [
        {
            "lb_algorithm": "SOURCE_IP",
            "protocol": "TCP",
            "description": "",
            "admin_state_up": true,
            "loadbalancers": [
                {
                    "id": "07d28d4a-4899-40a3-a939-5d09d69019e1"
                }
            ],
            "tenant_id": "1867112d054b427e808cc6096d8193a1",
            "session_persistence": null,
            "healthmonitor_id": null,
            "listeners": [
                {
                    "id": "1b421c2d-7e78-4a78-9ee4-c8ccba41f15b"
                }
            ],
            "members": [
                {
                    "id": "88f9c079-29cb-435a-b98f-0c5c0b90c2bd"
                },
                {
                    "id": "2f4c9644-d5d2-4cf8-a3c0-944239a4f58c"
                }
            ],
            "id": "3a9f50bb-f041-4eac-a117-82472d8a0007",
            "name": "my-pool"
        }
    ]
}