DNS Health Check Creation and Modification

Key information:

• Each health check configuration is specific to a single IP address/domain. As a result, the health check for each IP address or domain must be configured separately.
• An IP address/domain is eligible for health checks when it has been associated with a load balancing or failover configuration. For example, a health check configuration cannot be applied to an address record (i.e., A or AAAA) until it is part of a load balancing or failover configuration.
• The URI or IP address used to check a server/domain's health may point to any web server outside of our network (i.e., CDN). This allows the use of a server that monitors web servers and reports health information. Content verification may be used to verify the health of an individual server/domain.

• The creation or modification of a health check configuration will not be saved until Submit Group is clicked.

• View help on health check settings.

• After setting up a health check configuration, configure the relevant firewall(s) to allow our health check agents access to monitored servers.

  Learn more.

To add a health check configuration

1. Navigate to the Route (DNS) page.
2. Perform one of the following:
   • Load Balancing/Failover (CNAME/Subdomain): Click on the desired load balancing or failover configuration.
   • Load Balancing/Failover (Zone):
     1. Click on the desired zone.
     2. Click "Edit" corresponding to the load balancing or failover configuration that you would like to modify.
3. Click "Edit" corresponding to the desired IP address or CNAME.
4. Click Add HC.
5. In the Health Check Type option, select the type of health check that will be used to poll a server/domain and then perform one of the following procedures:
   • HTTP/HTTPS:
     1. In the Method Type option, select whether a GET or POST request will be sent.

     2. In the URI option, define the URI for the GET or POST request that will be sent.

        Specify any URI that resolves to a web server outside of our network (i.e., CDN).

     3. In the IP Version option, select whether the request will be sent over IPv4 or IPv6.
   • TCP:

     1. In the Ipv4 or IPv6 option, type the IP address to which the TCP request will be sent.

        Specify any IP address for a web server outside of our network (i.e., CDN).

     2. In the Port Number option, define the port over which TCP communication will take place.
6. Optional. In the Content Verification option, define the text through which health status will be verified. Our health check agents will search the body of the requested content for the specified text.
7. In the Seconds Between Checks option, define the time interval for which a health check will be performed from each of our health check agents.
8. In the Number of failed Checks option, define the number of consecutive times that a health check agent must achieve the same result (i.e., pass or fail) before it can determine health state (i.e., healthy or unhealthy).
9. In the Email Notification option, type the email address to which notifications will be sent for unhealthy servers/domains.
10. In the Reintegration Method option, define whether the server/domain associated with this health check can automatically be reintegrated into your load balancing or failover configuration after recovering from failed health checks.
11. Click Verify and Save. The health check configuration will be verified by polling a server/domain according to the defined settings.
12. Zone Only: Click Done.
13. Click Submit Group to save your changes.

To modify a health check configuration

1. Navigate to the Route (DNS) page.
2. Perform one of the following:
   • Load Balancing/Failover (CNAME/Subdomain): Click on the desired load balancing or failover configuration.
   • Load Balancing/Failover (Zone):
     1. Click on the desired zone.
     2. Click "Edit" corresponding to the desired load balancing or failover configuration.
3. Click "Edit" corresponding to the desired IP address or domain.
4. Click "Edit" under the Health Check column.
5. Make the desired changes.
6. Click Verify and Save. The health check configuration will be verified by polling a server/domain according to the defined settings.
7. Zone Only: Click Done.
8. Click Submit Group to save your changes.