Configuring a Health Check

Function

This API is used to configure a health check for a backend server group to check the status of backend servers. If the health check result is OFFLINE, backend servers are considered unhealthy. You need to check the server configuration.

Constraints

The security groups must have rules that allow access by 100.125.0.0/16.
If UDP is used for the health check, the protocol of the backend server group must be UDP.

URI

POST /v2/{project_id}/elb/healthmonitors

**Table 1** Parameter description
Parameter	Mandatory	Type	Description
project_id	Yes	String	Specifies the project ID.

Request

**Table 2** Parameter description
Parameter	Mandatory	Type	Description
healthmonitor	Yes	Healthmonitor object	Specifies the health check. For details, see Table 3.

**Table 3** **healthmonitor** parameter description
Parameter	Mandatory	Type	Description
tenant_id	No	String	Specifies the ID of the project where the health check is performed. The value must be the same as the value of project_id in the token. The value contains a maximum of 255 characters.
name	No	String	Specifies the health check name. The value contains a maximum of 255 characters.
delay	Yes	Integer	Specifies the maximum time between health checks in the unit of second. The value ranges from 1 to 50.
max_retries	Yes	Integer	Specifies the maximum number of retries. The value ranges from 1 to 10.
pool_id	Yes	String	Specifies the ID of the backend server group. Only one health check can be configured for each backend server group.
admin_state_up	No	Boolean	Specifies the administrative status of the health check. This parameter is reserved, and the default value is true.
timeout	Yes	Integer	Specifies the health check timeout duration in the unit of second. The value ranges from 1 to 50. NOTE: You are advised to set the value less than that of parameter delay.
type	Yes	String	Specifies the health check protocol. The value can be TCP, UDP_CONNECT, or HTTP.
monitor_port	No	Integer	Specifies the health check port. The port number ranges from 1 to 65535. The value is left blank by default, indicating that the port of the backend server is used as the health check port.
domain_name	No	String	Specifies the domain name of HTTP requests during the health check. This parameter takes effect only when the value of type is set to HTTP. The value is left blank by default, indicating that the private IP address of the load balancer is used as the destination address of HTTP requests. The value can contain only digits, letters, hyphens (-), and periods (.) and must start with a digit or letter, for example, www.test.com. The value contains a maximum of 100 characters.
url_path	No	String	Specifies the HTTP request path for the health check. The default value is /. The value starts with a slash (/). This parameter takes effect only when the value of type is set to HTTP. An example value is /test. The value contains a maximum of 255 characters.
expected_codes	No	String	Specifies the expected HTTP status code. The following options are available: A single value, such as 200 A list of values, such as 200,202 A value range, such as 200–204 This parameter takes effect only when the value of type is set to HTTP. The value contains a maximum of 64 characters. NOTE: This parameter is reserved.
http_method	No	String	Specifies the HTTP request method. The default value is GET. The value can be GET, HEAD, POST, PUT, DELETE, TRACE, OPTIONS, CONNECT, or PATCH. This parameter takes effect only when the value of type is set to HTTP. NOTE: This parameter is reserved.

Response

**Table 4** Parameter description
Parameter	Type	Description
healthmonitor	Healthmonitor object	Specifies the health check. For details, see Table 5.

**Table 5** **healthmonitor** parameter description
Parameter	Type	Description
id	String	Specifies the health check ID.
tenant_id	String	Specifies the ID of the project where the health check is performed.
name	String	Specifies the health check name.
delay	Integer	Specifies the maximum time between health checks in the unit of second. The value ranges from 1 to 50.
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.
pools	Array of Pools objects	Lists the IDs of backend server groups associated with the health check. For details, see Table 6.
admin_state_up	Boolean	Specifies the administrative status of the health check. This parameter is reserved. The value can be true or false. true: Enabled false: Disabled
timeout	Integer	Specifies the health check timeout duration in the unit of second. The value ranges from 1 to 50. NOTE: You are advised to set the value less than that of parameter delay.
type	String	Specifies the health check protocol. The value can be TCP, UDP_CONNECT, or HTTP.
monitor_port	Integer	Specifies the health check port. The port number ranges from 1 to 65535. The value is left blank by default, indicating that the port of the backend server is used as the health check port.
expected_codes	String	Specifies the expected HTTP status code. The following options are available: A single value, such as 200 A list of values, such as 200,202 A value range, such as 200–204 This parameter takes effect only when the value of type is set to HTTP. Currently, this parameter is not supported and is fixed at 200.
domain_name	String	Specifies the domain name of HTTP requests during the health check. This parameter takes effect only when the value of type is set to HTTP. The value is left blank by default, indicating that the private IP address of the load balancer is used as the destination address of HTTP requests. The value can contain only digits, letters, hyphens (-), and periods (.) and must start with a digit or letter, for example: www.test.com.
url_path	String	Specifies the HTTP request path for the health check. The default value is /. The value starts with a slash (/). This parameter takes effect only when the value of type is set to HTTP. An example value is /test.
http_method	String	Specifies the HTTP request method. The default value is GET. The value can be GET, HEAD, POST, PUT, DELETE, TRACE, OPTIONS, CONNECT, or PATCH. This parameter takes effect only when the value of type is set to HTTP. NOTE: This parameter is reserved.

**Table 6** **pools** parameter description
Parameter	Mandatory	Type	Description
id	Yes	String	Specifies the ID of the backend server group.

Example Request

Example request: Configuring a health check

POST https://{Endpoint}/v2/145483a5107745e9b3d80f956713e6a3/elb/healthmonitors

{
  "healthmonitor": {
    "admin_state_up": true,
    "pool_id": "bb44bffb-05d9-412c-9d9c-b189d9e14193",
    "domain_name": "www.test.com",
    "delay": 10,
    "max_retries": 10,
    "timeout": 10,
    "type": "HTTP"
  }
}

Example Response

Example response 1

{
  "healthmonitor": {
    "name": "",
    "admin_state_up": true,
    "tenant_id": "145483a5107745e9b3d80f956713e6a3",
    "domain_name": "www.test.com",
    "delay": 10,
    "expected_codes": "200",
    "max_retries": 10,
    "http_method": "GET",
    "timeout": 10,
    "pools": [
      {
        "id": "bb44bffb-05d9-412c-9d9c-b189d9e14193"
      }
    ],
    "url_path": "/",
    "type": "HTTP",
    "id": "2dca3867-98c5-4cde-8f2c-b89ae6bd7e36",
    "monitor_port": 112
  }
}