Load Balancers: Ultimate Guide to Understanding Types, Algorithms, Benefits, Industry Use-Cases and More

A recent study shows that 1 second of page load delay can drop the conversion rate by 7%. This means if your website drives sales of $200,000 a day, you can lose over $5 million a year in conversion!

Another study was done in 2021 surveying 1,200 IT security professionals representing 17 countries and 19 industries showed that 86% of organizations suffered from a successful cyberattack last year.

These alarming stats coupled with increasing business complexity and competitiveness mandate one thing: strengthening IT infrastructure to meet growing demands, offer impeccable client experience, and positively influence the bottom line.

Therefore, in this blog, we’re going to learn all about load balancers—an essential to every modern data center. You’ll learn how it offers a smooth client experience while helping you scale your applications, maintain their integrity, and secure your application and client’s sensitive information. So let’s dive in!

Table of content

  1. Load balancer fundamentals
  2. Benefits of load balancers
  3. Load balancing algorithm
  4. Types of load balancers
  5. Is load balancer right for your industry?
  6. Array Networks Load Balancer and Application Delivery Controller
  7. Wrapping up

Load Balancers Fundamentals

Availability and scalability are two of the biggest concerns for any business today. That’s where load balancer comes into play.

Load balancers are hardware or software-defined machines that aim to serve a single goal: to help you scale without ever worrying about the rise or fall in the incoming traffic for your apps. Load balances do this by sitting between your backend server farms and your clients.

Once a client request comes in, the load balancer sends the request to one of the servers in the backend based on one of the many algorithms. Then, it takes the response from the server and sends it to the client.

In doing so, the load balancers ensure that no single server is exhausted or overwhelmed by a large number of requests and that it performs optimally.

Now you might be wondering if that’s the primary job of a load balancer, why won’t you increase the number of servers in the backend to handle a high volume of traffic?

Well, while this is the primary job of a load balancer, its benefits stretch far enough:

  1. It checks the health of the servers so that no one of them is exhausted or overwhelmed.
  2. It allows for a routine checkup without any downtime issues.
  3. It shields your application against cyber threats like DDoS.

How Do Load Balancers Work?

When talking about traffic in the load balancers, we’re looking at memory capacity, CPU load, and network besides application traffic.

Acting as a reverse proxy, load balancers ensure that each system in the backend operates optimally without being underutilized or exhausting its capacity. When the client makes a request, they can only see a virtual IP address (VIP), while load balancers loop that request from the available server.

Load balancers work on various predetermined algorithms to function and are primarily used for bringing high availability and scalability to the business.

Since load balancers sit between the client and your applications, they perform other functions like content switching, blocking malicious traffic, detecting server failure, and directing traffic to other servers in the cluster. While this is the tip of the iceberg, let’s explore some of the other benefits of load balancers.

5 Benefits of the Load Balancer for Your Business

1. Enhances productivity

Once configured, load balancers keep a check on your backend system to provide a hiccup-free experience for your clients.

Moreover, it automatically optimizes each application’s delivery resources, directs traffic to the available server, and prevents server exhaustion or downtime.

2. Scalability

Load balancers are intelligent innovations of engineering that add or remove servers in the backend, depending on the load, and with minimal human interruption.

This means your clients can enjoy high availability despite the surge in traffic and do not have to face issues like latency, increased load time, or other such performance metrics. Furthermore, since this process is automated, it saves you time and cost.

3. Health checks

Before directing traffic to any one of the servers, load balancers perform a health check to ensure the server functions optimally and is available to take on the load.

Then, if the server is not responding, is down for maintenance, or facing any other issues, it automatically directs traffic to other servers in the backend. This means load balancers can help you enhance efficiency, maintain the health of your serves, and enable conducting scheduled server maintenance.

4. Security

Since load balancers sit between the application and client, it shields your servers from malicious attacks. One such attack is distributed denial of services (DDoS), where hackers flood the network by sending bot-driven traffic to exhaust server capacity. However, load balancers intelligently navigate these crimes by monitoring such traffic, identifying its packet contents, and blocking the same if an anomaly is detected. Finally, for enhanced protection, dedicate DDoS solution is recommended at the perimeter zone.

5. Flexibility and business continuity

One of the most significant advantages of load balancers is preventing downtime and drastic losses that arise from it. According to Gartner:

“The average cost of IT downtime is $5,600 per minute.” Moreover, 98% of organizations say a single hour of downtime costs over a thousand dollars. These alarming facts only reinforce that downtime is one of the most extreme business events.

Fortunately, load balancers can navigate these by optimizing the resource capacity, intelligently adding or removing servers in the backend, and performing other activities to avoid downtime.

Load balancers are intelligent gatekeepers that protect your application from all kinds of disasters. Moreover, it offers your clients a smooth experience while accessing your resources. Load balancers function on a set of mathematical calculations called the algorithm that defines which servers will receive which traffic and to what extent. Let’s discuss this in detail.

Load Balancing Algorithm

Round robin

This is one of the most commonly used and straightforward load balancing algorithms. Round robin distributes traffic to the serves in sequential order. For example: if there are 3 servers in the farm, namely A, B, and C. The first request is sent to server A, the second one to server B, the third one to server C, the fourth one to server A, etc. This method works on the assumption that each server has equal capacity, availability, and computing power. It does not take into account each request’s session time.

Weighted round-robin

Weighted round-robin is an advancement of the round-robin technique. Weighted round-robin is based on the principles of round-robin, i.e., it distributes requests sequentially.

The difference is that each server is assigned a weight by the administrator who loads balancer notes. For example: if server A is more powerful than server B and C, the first two connection requests will be sent to server A, the 3rd one to server B, 4th to server C, 5th to server A and so on.

Least connection

This algorithm, just like the round-robin one, assumes that all servers have the same computing capacity. However, it does differently by analyzing the number of active connections each server is occupied with. Then, the server handling the least number of active connections gets the request.

Shortest Response

The server with the shortest response time will get the next request. Using this metric you can intermix fast servers with slow servers and the fast servers will get more hits initially. As load increases, response time increases, and the slower servers will start to field more requests.

Simple Network Management Protocol (SNMP)

This method is based on the real server’s SNMP MIB information regarding the server’s status and availability. For example, the server’s CPU status and memory usage.

Source IP hash

This algorithm combines the server’s and client’s source and destination IP address and generates a unique hash key. This hash key is allocated to a server, and an advantage in this algorithm is that the broken connection can be re-established with the same server.

Persistent Cookie (PC)

A persistent cookie is used to associate a cookie name/value pair with a single real server on your backend. When setting up cookie-based policies keep in mind that you need a default policy for requests that do not have cookies in the HTTP header.

Now that we’ve understood what load balancers are and how it works, it’s time to understand their types. This is because when you’re looking for a load balancer for your enterprise, ensure that it aligns with your short and long-term goals and brings optimal ROI. So for that, let’s dive deeper and understand the different types of load balancers.

Types of Load Balancers

Application load balancers

Working on the 7th layer of the OSI model, application load balancers are made for the cloud environment. It’s more advanced as compared to its counterparts—besides analyzing each packet, it also checks its content such as HTTP header, URL, and more. While it serves all benefits that other load balancers do, it’s more advanced and also finds out possible coding and HTTP errors. Finally, they provide features like content awareness and switching.

Cloud load balancer

Being a software-defined load balancer, cloud load balancers distribute client requests to multiple apps hosted in the cloud setting. Besides its ability to boost performance, scale quickly, and offer high availability, it also keeps cost in check. Moreover, cloud load balancers work globally and enable content delivery to your client from a server closest to them.

Server and global server load balancers

A server load balancer is based on TCP/IP or DNS approach and distributes high volume sites to several servers using network-based hardware or software-defined appliances. When this technique works across several geo-locations, it’s called a global server load balancer.

Hardware vs. virtual load balancers

Virtual load balancers are virtualized application delivery controller software or a software-defined version of hardware load balancers.

A simple difference between hardware and virtual load balancers is that while the former is a hardware machine deployed in the physical data center, the latter is a software-defined load balancing system that uses the same code as its hardware counterparts.

Load balancers come in various shapes and sizes – offering various capabilities for different purposes. While companies of all types can leverage load balancers and make their applications efficient, here are some of the use cases of the load balancer. So if you’re wondering whether or not load balancers would be the right choice for your industry, keep reading!

Is Load Balancer Right for Your Industry?


Online banking is on the rise. According to Statista, 61.3% of Americans were using online banking in 2018, and this number is set to uplift to 65.3% in 2022. However, while online banking brings many benefits, the volume and sensitivity of data are high. If details like credit card credentials or bank login credentials slip into the hands of hackers, they can not only conduct catastrophic crimes but will also affect an individual’s identity. Thus, the onus is on the IT teams of BFSI sectors to ensure their networks are secure and they’re offering high-performing applications to their clients.

Educational Institutes

While the footsteps of technology were growing in the education sector, COVID-19 just accelerated that. In a recent stat by Statista, over 50% of respondents said everybody was attending online classes in their classroom. Moreover, Moodle, Google Classroom, and Zoom were the most common platforms used. Therefore, with the advent of online learning, it’s integral that students and teachers can connect securely and without any hiccups over internet-based applications. This calls for an urgent need for education sectors to be equipped with the latest tech to enable online learning. With solutions like a load balancer, your application will be better positioned to handle the spike in traffic, help students access learning material, and attend online classes without any hiccups.


A recent study shows that Telehealth use has increased by 38 times from the pre-COVID-19 baseline. After the lockdown hit the world, caregivers were motivated—more precisely, compelled—to offer online services.

This means amplified usage of applications that help patients schedule appointments, connect for video consultation, make transactions, and more.

While these applications make e-healthcare a breeze, there’s a dire need for infrastructure to support business needs in the long run.

This means the application should be scalable to support a high number of patients, secure sensitive patient information, and offer a high performance to the end-user. That’s where the load balancer saves the day. By absorbing spikes in traffic, efficiently managing load, and offering an unparalleled learning experience, educational institutes can benefit from the load balancers.


Online commerce is increasingly becoming the backbone of our economy. According to recent stats, e-commerce in 2021 accounted for approximately 19.6% of retail sales worldwide; it’s estimated that by 2025, it would segment for close to a quarter of total global retail sales.

Clearly, e-commerce will be a big part of our new normal.

However, for any e-commerce owner, there’s a set of technical challenges that cling to their web applications. Some of these are scalability and server capacity issues, a spike in the volume of traffic and transactions (especially during sales like Black Friday or other occasions), and the ever-growing complexities that add to the burden of IT teams.

Any hit to your availability means a direct toll on the bottom line. That’s why load balancers are essential for every e-commerce IT infrastructure. It helps your applications offer an unparalleled uptime by diverting traffic to the server with optimal capacity. With features like intelligent load balancing, content switching, and traffic directing, load balancers can save the day for e-commerce business owners.

The bottom line: each industry saves confidential customer information in their database, which needs to be protected from the malicious intent of hackers. Moreover, sudden spikes in traffic can cause a server to exhaust and die, causing a bottleneck in the traffic and downtime. Therefore, to avoid scenarios and losses borne by downtime, companies must opt for load balancers to ensure business continuity amidst uncertain situations, offer impeccable client experience, and boost the performance of their application.

Array Networks Load Balancers and Application Delivery Controllers

Growing business and IT complexities require having a reliable and robust IT infrastructure to support your business as it grows. This blog discussed load balancers as a vital element of IT infrastructure. They allow you to provide high availability, scalability, and prevent any bottlenecks in the network, providing impeccable service to the client. That’s where Array’s APV x800 series Application Delivery Controllers come into play.

Array’s application delivery controller provides industry-leading performance, boasts a complete suite of delivery features (inducing layer-7 server load balancing, SSL offload, caching, and more), and boosts application performance. Moreover, it’s made for the modern-day data centers and cloud environments that provide high ROI for service providers, enterprise, and public sector organizations. Our ADCs:

  • Provide protection against DDoS.
  • Delivers 99.999% application availability.
  • Intelligently reduces load and proves to be cost-efficient to protect your business-critical applications.
  • Are space and energy-efficient and consume 10-35% less power as compared to alternative solutions.

Moreover, our solutions can be deployed as:

  • Hardware: Our appliances can be deployed as hardware and are scalable to 100 Gbps of HW-accelerated SSL throughput. With multi-tenant network hyper-converged infrastructure, you can be assured of flexibility and high performance.
  • Software: available as permanent or subscription license, our software ADC virtual appliances support popular hypervisors including VMware, Hyper-V, and KVM.
  • Cloud: Available natively on industry-leading cloud platforms like AWS, Azure, and Google Cloud, our cloud solutions support utility consumption and BYOL license options.

Wrapping up!

Load balancers are a lifeline for your business today. Since your business relies heavily on web applications to offer unmatched quality of service to your clients, load balancers ensure you can do it efficiently and cost-effectively. Here’s a gist of what we covered in this blog post:

  1. Load balancers are intelligent gatekeepers for your application servers and other resources.
  2. It helps you deliver high availability to your clients and solve network bottleneck and scalability issues.
  3. Load balancers can also protect against several risks like DDoS by inspecting packet data.
  4. Load balancers work on a set of mathematical calculations called algorithms. These could be sequential or more advanced, such as round-robin, least connection, and IP hash. These algorithms ensure your servers perform optimally without any hiccups to the client. Plus, it checks the health of each server and allows for scheduled maintenance without any downtime.
  5. Load balancers are helpful for all kinds of industries, including BFSI, healthcare, and education. These machines allow enduring spikes in traffic, maintain the integrity of the appliances and secure your client’s confidential information.
  6. Array’s next-gen ADCs load balancers provide industry-leading performance and security of your resources while suppressing costs and complexities in the data center.

To know more about our load balancers, reach out to our sales team today!