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

Configuring a Health Check

Function

This API is used to configure a health check.

Constraints

The security groups must have rules that allow traffic to 100.125.0.0/16. If you want to use UDP for health checks, ensure that the protocol of the backend server group is UDP.

Calling Method

For details, see Calling APIs.

URI

POST /v3/{project_id}/elb/healthmonitors

Table 1 Path Parameters

Parameter

Mandatory

Type

Description

project_id

Yes

String

Specifies the project ID.

Request Parameters

Table 2 Request header parameters

Parameter

Mandatory

Type

Description

X-Auth-Token

Yes

String

Specifies the token used for IAM authentication.

Table 3 Request body parameters

Parameter

Mandatory

Type

Description

healthmonitor

Yes

CreateHealthMonitorOption object

Specifies the health check.

Table 4 CreateHealthMonitorOption

Parameter

Mandatory

Type

Description

admin_state_up

No

Boolean

Specifies the administrative status of the health check.

  • true (default): Health check is enabled.

  • false: Health check is disabled.

delay

Yes

Integer

Specifies the interval between health checks, in seconds. The value ranges from 1 to 50.

domain_name

No

String

Specifies the domain name that HTTP requests are sent to during the health check.

The value can contain only digits, letters, hyphens (-), and periods (.) and must start with a digit or letter.

The value is left blank by default, indicating that the virtual IP address of the load balancer is used as the destination address of HTTP requests.

This parameter is available only when type is set to HTTP.

Minimum: 1

Maximum: 100

expected_codes

No

String

Specifies the expected HTTP status code. This parameter will take effect only when type is set to HTTP or HTTPS.

The value options are as follows:

  • 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

The default value is 200. Multiple status codes can be queried in the format of expected_codes=xxx&expected_codes=xxx.

Minimum: 1

Maximum: 64

http_method

No

String

Specifies the HTTP method. The value can be GET, HEAD, POST, PUT, DELETE, TRACE, OPTIONS, CONNECT, or PATCH. The default value is GET.

This parameter is available when type is set to HTTP or HTTPS.

This parameter is unsupported. Please do not use it.

Minimum: 1

Maximum: 16

max_retries

Yes

Integer

Specifies the number of consecutive health checks when the health check result of a backend server changes from OFFLINE to ONLINE.

The value ranges from 1 to 10.

Minimum: 1

Maximum: 10

max_retries_down

No

Integer

Specifies the number of consecutive health checks when the health check result of a backend server changes from ONLINE to OFFLINE.

The value ranges from 1 to 10, and the default value is 3.

Minimum: 1

Maximum: 10

monitor_port

No

Integer

Specifies the port used for the health check. If this parameter is left blank, a port of the backend server will be used by default. The port number ranges from 1 to 65535.

NOTE:

This parameter is mandatory when Forward to Same Port is enabled for the associated backend server group.

Minimum: 1

Maximum: 65535

name

No

String

Specifies the health check name.

Minimum: 0

Maximum: 255

pool_id

Yes

String

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

project_id

No

String

Specifies the project ID.

Minimum: 1

Maximum: 32

timeout

Yes

Integer

Specifies the maximum time required for waiting for a response from the health check, in seconds. It is recommended that you set the value less than that of parameter delay.

Minimum: 1

Maximum: 50

type

Yes

String

Specifies the health check protocol. The value can be TCP, UDP_CONNECT, HTTP, or HTTPS.

Note:

  • If the protocol of the backend server group is QUIC, the value can only be UDP_CONNECT.

  • If the protocol of the backend server group is UDP, the value can only be UDP_CONNECT.

  • If the protocol of the backend server group is TCP, the value can only be TCP, HTTP, or HTTPS.

  • If the protocol of the backend server group is HTTP, the value can only be TCP, HTTP, or HTTPS.

  • If the protocol of the backend server group is HTTPS, the value can only be TCP, HTTP, or HTTPS.

url_path

No

String

Specifies the HTTP request path for the health check. The value must start with a slash (/), and the default value is /. The value can contain letters, digits, hyphens (-), slashes (/), periods (.), percentage signs (%), question marks (?), pound signs (#), ampersand signs (&), and the extended character set _;~!()*[]@$^:',+.

Note: This parameter is available only when type is set to HTTP or HTTPS.

Default: /

Minimum: 1

Maximum: 80

Response Parameters

Status code: 201

Table 5 Response body parameters

Parameter

Type

Description

request_id

String

Specifies the request ID. The value is automatically generated.

healthmonitor

HealthMonitor object

Specifies the health check.

Table 6 HealthMonitor

Parameter

Type

Description

admin_state_up

Boolean

Specifies the administrative status of the health check.

  • true (default) indicates that the health check is enabled.

  • false indicates that the health check is disabled.

delay

Integer

Specifies the interval between health checks, in seconds. The value ranges from 1 to 50.

Minimum: 1

Maximum: 50

domain_name

String

Specifies the domain name that HTTP requests are sent to during the health check.

The value can contain only digits, letters, hyphens (-), and periods (.) and must start with a digit or letter.

The value is left blank by default, indicating that the virtual IP address of the load balancer is used as the destination address of HTTP requests.

This parameter is available only when type is set to HTTP.

expected_codes

String

Specifies the expected HTTP status code. This parameter will take effect only when type is set to HTTP or HTTPS.

The value options are as follows:

  • 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

The default value is 200. Multiple status codes can be queried in the format of expected_codes=xxx&expected_codes=xxx.

http_method

String

Specifies the HTTP method. The value can be GET, HEAD, POST, PUT, DELETE, TRACE, OPTIONS, CONNECT, or PATCH. The default value is GET.

This parameter is available when type is set to HTTP or HTTPS.

This parameter is unsupported. Please do not use it.

id

String

Specifies the health check ID.

max_retries

Integer

Specifies the number of consecutive health checks when the health check result of a backend server changes from OFFLINE to ONLINE.

The value ranges from 1 to 10

Minimum: 1

Maximum: 10

max_retries_down

Integer

Specifies the number of consecutive health checks when the health check result of a backend server changes from ONLINE to OFFLINE.

The value ranges from 1 to 10, and the default value is 3.

Minimum: 1

Maximum: 10

monitor_port

Integer

Specifies the port used for the health check. If this parameter is left blank, a port of the backend server will be used by default. The port number ranges from 1 to 65535.

Minimum: 1

Maximum: 65535

name

String

Specifies the health check name.

pools

Array of PoolRef objects

Lists the IDs of backend server groups for which the health check is configured. Only one ID will be returned.

project_id

String

Specifies the project ID.

timeout

Integer

Specifies the maximum time required for waiting for a response from the health check, in seconds. It is recommended that you set the value less than that of parameter delay.

Minimum: 1

Maximum: 50

type

String

Specifies the health check protocol. The value can be TCP, UDP_CONNECT, HTTP, or HTTPS.

Note:

  • If the protocol of the backend server group is QUIC, the value can only be UDP_CONNECT.

  • If the protocol of the backend server group is UDP, the value can only be UDP_CONNECT.

  • If the protocol of the backend server group is TCP, the value can only be TCP, HTTP, or HTTPS.

  • If the protocol of the backend server group is HTTP, the value can only be TCP, HTTP, or HTTPS.

  • If the protocol of the backend server group is HTTPS, the value can only be TCP, HTTP, or HTTPS.

url_path

String

Specifies the HTTP request path for the health check. The value must start with a slash (/), and the default value is /. The value can contain letters, digits, hyphens (-), slashes (/), periods (.), percentage signs (%), question marks (?), pound signs (#), ampersand signs (&), and the extended character set _;~!()*[]@$^:',+.

Note: This parameter is available only when type is set to HTTP or HTTPS.

created_at

String

Specifies the time when the health check was configured. 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 health check 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.

Table 7 PoolRef

Parameter

Type

Description

id

String

Specifies the ID of the backend server group.

Example Requests

Configuring a health check whose protocol is HTTP

POST https://{ELB_Endpoint}/v3/99a3fff0d03c428eac3678da6a7d0f24/elb/healthmonitors

{
  "healthmonitor" : {
    "name" : "My Healthmonitor",
    "max_retries" : 3,
    "pool_id" : "488acc50-6bcf-423d-8f0a-0f4184f5b8a0",
    "type" : "HTTP",
    "timeout" : 30,
    "delay" : 1
  }
}

Example Responses

Status code: 201

Normal response to POST requests.

{
  "request_id" : "0e837340-f1bd-4037-8f61-9923d0f0b19e",
  "healthmonitor" : {
    "monitor_port" : null,
    "id" : "c2b210b2-60c4-449d-91e2-9e9ea1dd7441",
    "project_id" : "99a3fff0d03c428eac3678da6a7d0f24",
    "domain_name" : null,
    "name" : "My Healthmonitor",
    "delay" : 1,
    "max_retries" : 3,
    "pools" : [ {
      "id" : "488acc50-6bcf-423d-8f0a-0f4184f5b8a0"
    } ],
    "admin_state_up" : true,
    "timeout" : 30,
    "type" : "HTTP",
    "expected_codes" : "200",
    "url_path" : "/",
    "http_method" : "GET"
  }
}

Status Codes

Status Code

Description

201

Normal response to POST requests.

Error Codes

See Error Codes.