What Is Load Balancing and How Does A Load Balancer Work?

Load balancing is the process of managing or allocating traffic over a number of servers. A load balancer is the device that makes this possible.

In today's tech-centric market, it's vital to have reliable, speedy connections to stay on top of projects, communication and so much more. If you're having issues with server reliability or stability, it’s important to understand what load balancing is and how a load balancer can be used to solve these issues. 

What is Load Balancing?

The goal of load balancing is to optimize speed and performance for all users across a network by efficiently distributing traffic among servers. When a network of servers is load balanced, no server is overloaded with traffic or heavy application use, so data is always available to every user.

Load balancing helps to support servers that handle different regions or functions to cut down on inefficiency, packet loss, and latency, creating an optimal experience for all users.

What is a Load Balancer?

A load balancer is the device that makes load balancing possible. A load balancer is used to distribute high volumes of data and information evenly across multiple servers in a given network. This increases overall productivity for users and connected devices.

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How Does Load Balancing Work?

Load balancing is achieved by having dedicated servers deployed to distribute traffic. A scheduling algorithm divides tasks to ensure maximum efficiency and speed. To keep speed and utilization high, new requests can be sent to the servers with the least CPU usage, shortest queue times, lowest volume of lost data packets or lowest number of active connections.  

Common Load Balancing Algorithms

Load balancing can be achieved through the use of various algorithms, which define how the traffic should be distributed across the network. Here are some of the most common types of load balancing algorithms:

• IP Hash: An IP hash helps direct traffic to particular servers based on users' IP addresses. This method of load balancing is ideal for organizations that have an international or global scale to keep in mind, such as an online gaming portal or eCommerce platform.
• Round Robin: A round robin algorithm essentially requires the servers in the network to take turns handling a traffic load. Requests are sent to the servers sequentially. This typically works best when using identical servers that can process the same number of requests.
• Least Connections: As the name might imply, this algorithm passes requests to the server that currently has the least number of connections (active sessions). Even if your servers are identical, it is still possible for one server to bottleneck before another. A least connections algorithm can help to ensure that traffic is distributed more evenly.
• Weighted Algorithms: There are weighted round robin and weighted least connections algorithms. These modify their counterparts by giving preference or “weight” to particular servers. An administrator can configure the network to give weight to individual servers in the network, which will be factored into routing decisions along with round robin or least connection considerations. This may make sense if you have servers with varying capacity across your network.
• Random: Best used with a network of identical servers, a random algorithm will randomly distribute requests. This is similar to a round robin setup, but instead of sending requests to the servers sequentially, a random number generator is used to determine the server that will receive the current request.

Types of Load Balancers

There are two primary types of load balancers, including layer 4 (network) balancers and layer 7 (application) balancers. Each offers advantages depending on the type of traffic you need to manage:

• Layer 4: Layer 4 load balancers are used for network load balancing. Routing decisions are made based on network layer information. This is one of the fastest implementations, but it is not as effective at evenly distributing traffic.
• Layer 7: Layer 7 load balancers are used for HTTP/HTTPS load balancing. This is also known as application load balancing. Layer 7 load balancing is flexible, allowing for dynamic host port mapping and the distribution of traffic with data passed via an HTTP address.

Benefits of a Load Balancing

Key benefits of adding load balancers to your network include improved scalability, performance optimization, reduced bottlenecking, and flexible resources in disaster recovery situations. Let’s take a closer look at each:

Quick and Seamless Scalability

Load balancing servers are often utilized by companies and organizations for large amounts of users accessing their servers. These uses range, with examples including applications, video streaming, news articles or social networking. If remote users are accessing the network, such as a salesperson showing a marketing video or presentation to potential clients, those requests are handled seamlessly. The beauty of a load balancer on these servers is that, when more processing power or storage is necessary, companies can reach out to their service provider for additional servers deployed on their network. 

Optimal Performance for All Users

For businesses that need a large network of servers to maintain corporate data, load balancing is also vital to help distribute optimal speed and performance for all users. With the right load balancing setup, requests can be quickly and efficiently directed to servers with the load amount of load for faster response times. This solution works out well when servers are undergoing planned maintenance, as well. Instead of taking down the network or going offline, maintenance can be carried out one server at a time while the rest of the network handles requests without sacrificing performance. 

Resilient, Highly Available Server Networks

When your servers are load balanced, it leaves you with a more stable, resilient network that has much more fault tolerance. If one server goes down in your network, the next one in line can handle that server's intended requests, and so on. This means no effect on performance or availability, even if one server in your network is down. This also applies to applications: If an application fails on one server, the next server in the network still has it available.

Disaster Recovery

When it comes to disaster recovery, load balancing is a great help for any company's IT solution. If your primary data center has an issue, a load distributed network can act as a disaster recovery service through the redirection of user requests to servers in a disaster recovery data center. The load balancer is well-equipped to determine which servers are best capable of processing requests and then sends those requests to those specific servers. 

Find the Best Load Balancer for Your Business

If you're in the market for implementing a load balancer as a means of optimizing your company's network performance and want more information, talk with one of our experts today to discuss the most effective load balancer service for ensuring your speeds and reliability are always at their peak.