Since its inception in the 1990s, load balancing has played an integral role in how traffic is distributed across networks. Whether your servers are exclusively in the cloud, in a data center, or on-site, load balancers are critical in keeping the flow of data moving smoothly and efficiently between servers and endpoints.
One of the most common and affordable load balancing techniques is Round Robin. This configuration is done by assigning two or more IP addresses to the same DNS record. Once IPs are assigned, your traffic is distributed evenly across your network, cycling through each endpoint in a circular fashion.
Some DNS providers, like Constellix, also offer Weighted Round Robin or Weighted Load Balancing, which essentially does the same thing as regular Round Robin, but allows you to distribute weight unevenly. We’ll cover the differences between these two options in more detail below.
Benefits of Load Balancing
Load balancing is beneficial as it ensures no single server bears the brunt of your traffic load. This not only improves performance but also ensures end users are able to reach your site, even if one of your resources is unhealthy or down.
How Load Balancing Helps Secure Your Networks and Systems
Another advantage of using load balancing is DDoS (distributed denial-of-service) and cyber threat mitigation. Since basic or weighted Round Robin splits traffic between servers, not all end users will be affected if one of your servers is attacked. The caveat is that Round Robin doesn’t check for downed IPs, so some traffic would still be sent to an unhealthy resource. When paired with Failover; however, traffic will automatically cycle to the next IP you’ve specified in your configuration. By taking a preventative approach, you’ll ensure minimal damage in the event of an outage, as most users will still reach their destination.
Keep in mind: TTL values affect how quickly traffic is cycled between IPs in load balancing configurations. If they are too high, you lose effectiveness. If they are set too low, it increases the load on your servers. The ideal TTL for Round Robin configurations is 180-300 seconds.
Now, let’s take a look at these two types of load balancing methods and how they differ.
Basic Round Robin distributes traffic evenly across multiple servers. You can think of it as a rotor that cyclically returns one endpoint at a time. For instance, if you had two or more records (A, AAAA, ANAME, CNAME) with the same name configured to point to different IP addresses, then queries will have a 50/50 chance of being returned by either of the IPs in your configuration.
Weighted Round Robin
Weighted Round Robin is a more advanced load balancing configuration. This technique allows you to point records to multiple IP addresses like basic Round Robin, but has the added flexibility of distributing weight based on the needs of your domain. This is done by creating DNS record pools, which will be rotated based on the values you set—and, of course, these values don’t need to be equal.
Round Robin vs Weighted Load Balancing
The obvious difference between basic Round Robin and Weighted Round Robin is how weight is distributed. Whereas Round Robin requires an equal distribution, Weighted Load Balancing methods allow you to set values unequally.
Rather than rotating equal amounts of traffic between IP addresses in a pool, Weighted Round Robin will distribute queries based on your specified values. The advantage to this is that you can spread your web traffic across servers based on their capacity size, geographical location, or speed. For instance, in a weighted load balancing configuration, you can ensure a specific resource only receives a certain amount of traffic. This helps prevent a server that receives larger numbers of queries from becoming completely overloaded.
You can also use Weighted Round Robin for A/B testing or for implementing updates to specified segments of your users.
Load Balancing: A Necessity for Any Online Application
So, who wins this matchup? Well, Weighted Round Robin has more flexibility and in many cases, when put against basic Round Robin, it’s a TKO—but the answer depends largely on your domain needs. What is certain, however, is that some type of load balancing is crucial in today’s online-centric climate.
If you’re still unsure, try analyzing your DNS queries, past and present. This will give you an idea of where your traffic is coming from and help you identify weaknesses and vulnerabilities in your configurations.
Did you know?: Constellix (sister company of DNS Made Easy) is the only provider in the industry that offers advanced DNS analytics, which includes historical and real-time data, as well as the ability to see anomalies as they happen.
Some other points of consideration for determining which load balancing technique is right for you are:
- Are your servers geographically distributed?
- What amount of traffic does your domain typically receive?
- Do all of your servers have enough capacity to handle your traffic if one goes down?
- Are you, or do you plan to use Round Robin in conjunction with another load balancing technique, such as Failover or load balancing software?
Whatever you decide, both basic and weighted Round Robin will provide you with a solid load balancing option. You’ll see improved performance for your domain(s) and will be providing your consumers with a better end-user experience.
For information on Constellix or DNS Made Easy products and services contact us. Our specialists will be happy to discuss your specific needs and work with you to find the perfect DNS solutions for your business.
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