CNAME/ANAME failover is conceptually the same as A record failover but with the flexibility of aliases, allowing for more elaborate and reliable configurations and monitoring services. Setting up CNAME and ANAME failover is the exact same process so for this tutorial we will focus on CNAME. For more information on CNAME and ANAME records, click here.
1. Go To Sonar
First, you want to log into the Constellix control panel through the Sonar application. If you are already logged into another Constellix application, use the menu button in the top left corner to switch to the Sonar application.
2. Add Check
From the dashboard, click Add Check and choose the kind of check you want to create. There are four different kinds of checks you can create: Web, TCP, DNS and RUM. In this example, we will create a web check to monitor the IP addresses of our web servers.
3. Configure Check
For directions on setting up a Web Check, click here.
Repeat this step for each CNAME record that you wish to include for the failover setup.
Now that your Sonar checks are setup, go back to the control panel to create the failover record.
4. Select Managed DNS and click on Domains
5. Select your Domain
6. Add Failover Record Information
A. Name: This will be the hostname for your record. It is important to note, the domain name is automatically appended to the “Name” field of the record. Note the name field is required, because a CNAME record can not be defined for the root record of the domain.
B. TTL: Edit the TTL. Time to Live is measured in seconds and is the amount of time the record will cache in resolving name servers and web browsers. Please note that a lower TTL in any failover setup is preferred as the cached record in the resolver will update sooner allowing for less of a delay in redirected resolution.
C. Record Mode: The Record Mode will be switched to Failover for this tutorial.
H. Host: Once Failover is selected under Record Mode, a new window will populate below. Enter the FQDNs that you previously created checks for into the boxes below “Host”. If you have more than two, click the “+ Add Another Host” button to populate more fields.
I. Sonar Check: Click the fields below the word “Sonar Check” and select from the drop down menu or type in the name of the specific checks you created that correspond with the FQDNs in the setup.
Click Save And Close at the bottom of the window and then, as with all changes in the account, go to the top of the page and “click here” to review and apply changes. Click the green Commit Changes button and you’re all set!