Round Robin is a DNS load balancing technique that distributes web traffic evenly between servers or by preference if using Weighted Round Robin. Each time a record using this configuration is queried, the query will cycle through your endpoints and be returned by the next resource in the queue. Round Robin can also be configured with our Failover service, which is highly recommended. This guide will walk you through the process of configuring the two services together.
While Round Robin helps prevent resources from becoming overloaded, it doesn’t check if a server is down. This means some queries could still be sent to an unhealthy endpoint. Configuring Round Robin with Failover will prevent traffic from being returned to resources experiencing a failure. With this configuration, you can avoid disruption in service for your end users.
For this tutorial, we will be demonstrating how to configure Round Robin with Failover using A records, but the same steps apply when using AAAA, CNAME, and ANAME records.
A. Name: Enter the hostname for the record.
B. TTL: Time to live (measured in seconds) determines how long a record is cached in nameservers. Visit our What is TTL resource for more information and best practices for TTLs.
C. Geo Proximity: The Geo Proximity rule allows you to optimize web traffic by specifying the locations of IP addresses for your DNS A records.
D. IP Filter: This feature lets you configure an IP Filter for your record.
E. Disable Record: This option allows you to remove records from our nameservers without removing the record configuration in the Constellix DNS control panel. See our Disabling a Record tutorial for more information.
F. Record Mode: This mode enables you to configure Failover, Record Pools, or Round Robin with Failover. Visit our Records Mode page for more details on these settings. For this tutorial, select Round Robin with Failover.
There are three Failover settings to choose from. You will also want to designate a contact for failover alerts:
G. Contact Notify: Select the contact list that will receive Failover notifications. If you need help with this step, see our Create a Contact tutorial.
6. Add IP for Failover Configuration
In the same window, you will also need to add the resources for your Round Robin/Failover configuration and select the appropriate previously made Sonar check.
H. IP: Add the IP, starting with your primary. Click Add Another IP to add additional resources.
I. IP: For this configuration, at least two endpoints are required. Enter your backup resource in this field.
J. +Add Another IP: This option lets you add additional endpoints.
K. Sonar Check: Select the Sonar Check you would like to use for monitoring your resources.
L. Enabled: This allows you to disable endpoints in your Failover configuration at any time (useful for planned maintenance or updates).
M. Active: This column displays whether an endpoint is active or not. The resource that is currently being returned will have a green checkmark beside it.
N. Status: The Status column will denote whether a host is up or down. If your primary resource is active, the status will say n/a.
O. Notes: The note section lets you add important details and keywords so you can easily search for specific records later (optional, but recommended).
Save: Once you have entered all endpoints and have chosen Sonar checks for each, click the green Save and Close button to complete your configuration.
7. Test Your Failover Configuration
Once you have reviewed and committed your changes, your configuration will instantly propagate to all of our nameservers. To verify that the record is live, you can query it through Mac’s Terminal or the Windows Command Prompt (or PowerShell). Alternatively, you can use our DNS Lookup Tool, which can be used anywhere, from any device.
You can also see your configuration in the main Records area. If you click on the IP for the record with the Round Robin/Failover configuration, the endpoint that is being returned will be designated with an asterisk in the IP/Pool column.
Visit our website for more information on our services and features.