Configuring a Health Check

Scenario

You can configure a health check to detect unhealthy endpoints and ensure service reliability and availability.

Constraints

• For UDP listeners, ensure that the security group rules configured for each endpoint allow ICMP traffic over the health check port.
• Ensure that the security group rules configured for each endpoint allow traffic from given CIDR blocks over the health check port.

  For details, see Table 1.

  Table 1 CIDR blocks that need to be allowed

  Endpoint Type	Endpoint Group Region	CIDR Blocks to Be Allowed
  EIP Custom EIP	N/A	122.9.234.0/23 116.196.216.0/23 124.71.242.0/23
  ECS ELB IP address Custom domain name	CN North-Beijing4	1.92.116.0/26 1.92.117.0/26
  	CN East-Shanghai1	60.204.194.192/27 60.204.195.192/27
  	CN South-Guangzhou	110.41.74.0/25 110.41.75.0/25
  	CN-Hong Kong	190.92.249.0/26 190.92.250.0/26
  	AP-Singapore	101.44.164.192/27 101.44.165.192/27
  	TR-Istanbul	101.44.42.0/27 101.44.43.0/27

Procedure

1. Log in to the management console.
2. Click in the upper left corner and choose Networking > Global Accelerator.

   The Global Accelerator page is displayed.

3. Search for the global accelerator by name or ID.
4. Click the name of the global accelerator to go to the details page.
5. Click Endpoint Groups.
6. Click the name of the endpoint group.
7. In the basic information area, click Configure next to Health Check.
8. Specify the parameters listed in Table 2.

   Table 2 Parameters required for configuring a health check

   Parameter	Description
   Health Check	Whether to enable health check. If you disable health check, requests may be forwarded to unhealthy endpoints.
   Protocol	The health check protocol can be TCP. Default value: TCP.
   Port	The port used for health check. The port number ranges from 1 to 65535.
   Advanced Settings
   Interval (s)	The maximum time between two consecutive health checks, in seconds. The interval ranges from 1 to 60.
   Timeout (s)	The maximum time required for waiting for a response to a health check request, in seconds. The timeout ranges from 1 to 60.
   Maximum Retries	The maximum number of health check retries allowed. The value ranges from 1 to 10.

9. Click OK.