In this article we will focus on Round Robin Load Balancing. Such techniques are important because the traffic on the internet is constantly increasing. There are more devices connected and the data that circuit is more too. In order to manage all of this load, you need a load balancing solution that distributes it among the servers to reduce the load. Round Robin is the perfect solution in this situation! Let’s explain a little bit more about it!

What is Round Robin Load Balancing?

Round Robin Load Balancing is a simple technique for spreading incoming traffic across multiple servers. It cyclically forwards client requests via a group of servers to effectively balance the server load. It is excellent in cases when the servers are very similar in their computational and storage capacities. 

Round Robin Load Balancing is most commonly used because of its simplicity. Its implementation is rather straightforward. It is a distributor that redirects the traffic from different users to the servers in order. Let’s see an example. Imagine you have 6 users (u1, u2, u3, u4, u5 and u6) who want to connect and you have 3 servers (s1, s2 and s3). U1 will connect to s1, u2 to s2, u3 to s3 and it will start all over again u4 to s1, u5 to s2 and u6 to s3. Can you guess to which will it connect the next user 7? Yes, it will connect to s1.

It takes into account just when somebody wants to connect. Nothing more. It will definitely serve as a load balance, based on this logic, but ignore all other parameters. So you will have reduced load on the network, but you can have different problems.

Maybe your servers are not equal. Imagine server 1 (s1) is a lot faster than the rest. With more RAM, better CPU, etc. It will still receive the same traffic as the rest which are weaker. It is not the most efficient scenario. For that reason, Round Robin Load Balancing works best with the same configuration of servers.

How does Round Robin Load balancing work?

Round Robin Load Balancing functions under a very easy-to-understand mechanism. As we mentioned earlier, this technique forwards requests cyclically between servers. They are sequenced depending on the order they arrive. This mechanism is especially helpful during high incoming traffic and keeps the load balanced. 

Here is an illustration of how Round Robin Load Balancing actually works. Let’s imagine a company that holds a group of four servers: A, B, C, and D, and many users send requests to connect with their website:  

• Server A gets request 1
• Server B gets request 2
• Server C gets request 3
• Server D gets request 4

The rotation starts all over again when the load balancer continues to send requests to servers. 

But what if one of the servers has the capacity to handle more requests compared to others? Then you can implement Weighted Round Robin (WRR)!

Weighted Round Robin (WRR)

Weighted Round Robin is a little bit more advanced configuration for balancing the load. Yet, it is a perfect opportunity if one of your servers has better characteristics than the rest. The administrator can assign weight to every server in the group based on chosen criteria. In a most popular scenario, the criterion is the server’s traffic‑handling capacity.

This variation of Round Robin takes into account the previous case, where one server is better than the rest. Imagine the s1 is twice more powerful than s2 and s3. We will assign it higher weight because it can handle a more significant load. Because we did this, it will get more traffic.

Following the example, u1 will connect to s1, then u2 will again connect to s1. This is the main difference. U3 will connect to s2, u4 to s3, then again u5 to s1 and u6 to s1. U7 will connect to s2.
There is another scenario where Weighted Round Robin can be useful. Maybe your servers are similar, but you have more important information in one, you want it to have less weight. So, it that case you assign higher values to the rest of the servers. This way they will handle more load and your essential server will have less work and less chance to crush.

Suggested article: What is Load Balancing?

Advantages and Disadvantages

Round Robin is a simple and widely used load balancing algorithm that distributes incoming network traffic across a group of servers. Like any other method, it has its own set of advantages and disadvantages. Here are the main benefits and drawbacks of the Round Robin Load Balancing mechanism:

Advantages

• Simplicity: It is an easy-to-understand and easy-to-apply technique. Additionally, it does not require much effort to set up, works on a clear mechanism, and has an uncomplicated framework.
• Even Distribution: It provides a relatively even distribution of incoming requests across the available servers. Each server gets an equal share of the load, which is beneficial when all servers have similar processing capabilities.
• Low Latency: Round Robin is generally low in terms of latency because it doesn’t involve complex decision-making processes. It simply follows a predictable rotation.
• Scalability: Round Robin is easy to scale horizontally. When you add more servers to your pool, they can be smoothly integrated into the rotation without major reconfiguration.

Disadvantages

• Deficiency of functionalities: The simplicity of this mechanism is also its main drawback. Many experienced administrators prefer to utilize Weighted Round Robin or more complicated algorithms. 
• Lack of Intelligence: Round Robin doesn’t consider the actual load or health of individual servers. It treats all servers as equal, which can be problematic if some servers are underutilized while others are overloaded. This can lead to inefficient resource allocation.
• Stateless Nature: It’s a stateless algorithm, meaning it doesn’t consider the current state of the server (like CPU load or memory usage). This lack of awareness can lead to not-so-optimal performance.

Can I use Round Robin Load Balancing with ClouDNS?

Yes, you can use Round Robin Load Balancing with ClouDNS. It is an included feature in both paid and free plans. You can easily sign up for a free account.

Here’s how you can use Round Robin load balancing with ClouDNS:

1. Register your domain with ClouDNS: If you haven’t already, register your domain with ClouDNS or transfer your existing domain to our DNS service.
2. Create DNS records: In the ClouDNS control panel, you can easily create DNS records. For Round Robin load balancing, you can use A records, AAAA records and ALIAS records, but you can’t use CNAME records with any other DNS record for the same host.
3. Set TTL values: Configure the Time to Live (TTL) values for your DNS records. TTL determines how long DNS resolvers should cache the DNS records. 
4. Regularly update DNS records: If you need to add or remove servers from the load balancing pool, you can do so by updating the DNS records in the ClouDNS Control Panel.
5. Monitor and optimize: Regularly monitor the performance of your load balancing setup and make adjustments as necessary to ensure that traffic is evenly distributed.

If you have any additional questions, you can contact our 24/7 Live chat support!

When to Use Round Robin Load Balancing

Round Robin Load Balancing is ideal for scenarios where all servers in the pool have similar resources and capacity. It is well-suited for small to medium-scale applications where even traffic distribution is the main concern. For example, small businesses with limited servers can effectively use this method to ensure their websites or applications stay responsive and balanced under normal traffic conditions.

However, if your infrastructure has servers with varying performance levels or inconsistent resource availability, more advanced load balancing algorithms like Weighted Round Robin or Least Connections may be necessary. Understanding when to use Round Robin is key to optimizing its efficiency in your particular setup.

Round Robin vs. Other Load Balancing Algorithms

Round Robin is just one of many load balancing algorithms. Depending on your needs, other methods may be more suitable:

• Least Connections: This algorithm directs new requests to the server with the fewest active connections, which can help ensure better resource utilization when server loads vary significantly.
• IP Hash: This method directs traffic based on the client’s IP address. It ensures that each client consistently connects to the same server, which is beneficial for maintaining session consistency.
• Weighted Least Connections: This approach combines the advantages of Least Connections and Weighted Round Robin, ensuring that more powerful servers handle more connections while still considering their current load.

Common Use Cases

Round Robin Load Balancing is commonly used in the following scenarios:

• Web Hosting: Distributing web traffic evenly across a set of identical servers to balance the load and prevent any one server from becoming overwhelmed.
• Content Delivery Networks (CDNs): In some CDN setups, Round Robin Load Balancing can be used to distribute content requests across different servers in the network, helping to ensure faster delivery.
• E-commerce Websites: Small to mid-sized e-commerce sites may use Round Robin to distribute user sessions across multiple servers, ensuring that no single server handles too much traffic during peak shopping times.

Conclusion

Round Robin Load balancing is a fundamental technique for distributing network traffic efficiently across multiple servers. It offers a simple and easy-to-implement method for ensuring optimal resource utilization and high availability. By cyclically assigning incoming requests to servers in a sequential manner, Round Robin helps prevent overload on any single server, facilitating fault tolerance and load distribution. While it may not consider server health or actual load, it serves as a cost-effective solution for basic load distribution requirements. However, for more complex scenarios, advanced load balancing algorithms may be preferred. Finally, Round Robin Load balancing remains a valuable tool in the arsenal of network administrators.

Vasilena Markova

Hello! My name is Vasilena Markova. I am a Marketing Specialist at ClouDNS. I have a Bachelor’s Degree in Business Economics and am studying for my Master’s Degree in Cybersecurity Management. As a digital marketing enthusiast, I enjoy writing and expressing my interests. I am passionate about sharing knowledge, tips, and tricks to help others build a secure online presence. My absolute favorite thing to do is to travel and explore different cultures!