Insights

What Is a Load Balancing Server? And Why Do You Need One?

Written by Databerry | February 18, 2019
Maintaining 100% uptime on your network is impossible if all your traffic flows through a single server. Even if you route your traffic through multiple channels, there's still the possibility of serious downtime during maintenance or server failure. And even when all your servers are functional, a spike in traffic can overload them and result in poor network performance. If you want to maintain an efficient and reliable network without downtime, load balancing is an absolute must. But what exactly is load balancing, and how can it benefit your business's digital infrastructure? Keep reading to find out.

What Is Load Balancing?

Put simply, load balancing involves spreading out ("balancing") network traffic (the "load") across multiple servers. This process allows a computer network to process high amounts of traffic and run many applications at once without overwhelming any one server or machine. The first hardware-based server load balancers (SLBs) were developed in the 1990s. Over time, these load balancing capabilities were also transferred to software and cloud-based servers. Modern SLBs are efficient, flexible, and secure. If your network and user demand are growing, it may be time to look into what options are available.

How Do Load Balancing Servers Work?

Think of a load balancer as a manager that controls the flow of data between a server network and all the devices that access it. The load balancer chooses which server will provide the best user experience each time a computer connects. Load balancing can be done either by a physical server, a software application, or some combination of the two. Local hardware-based SLBs are generally sold in pairs to prevent data loss and server compromise if one of them fails. They can also be located off-premise in a data center. Most software or cloud-based SLBs run as a single function of a larger Application Delivery Controller (ADC) program. Along with load balancing, an ADC can also manage application speed, firewalls, traffic shaping, and data compression.

Load Balancing Methods

Load balancing servers use a variety of different algorithms to distribute network traffic. The algorithms, known as "methods," are each used in different situations depending on a network's unique needs.
  • Round Robin - Round Robin has historically been the default method of load balancing. This algorithm cycles through a sequence of servers and sends traffic to the first available one, which is then moved to the bottom of the list. Round Robin is useful when connections are variable and the network consists of a series of equally capable servers.
  • Hash - Servers are chosen based on criteria such as the client's IP address or HTTP headers. It's most useful for applications that store client-specific data over multiple sessions.
  • Least Connections - Incoming traffic is directed to the server with the fewest active network connections. This method is useful for networks with persistent and unequally distributed traffic.
  • Least Response Time - One step above the Least Connections method. This algorithm selects for the server with both shortest response time and fewest active connections.
  • Least Bandwidth - Servers are selected based on which has the smallest amount of active traffic. Bandwidth is measured in megabits per second.
  • Custom Load - The load balancer first tries to select a server with no active network traffic. If there are no inactive servers, the one with the smallest load is chosen.
Your network's traffic load and the types of applications used will determine which method is most beneficial. The algorithm may evolve over time along with your user demand. An experienced managed IT services provider can help you choose the best database solution and load balancing method for your business.

Load Balancing Capabilities

According to the seven-layer OSI model, load balancing occurs between layers four and seven. Load balancing servers have a variety of capabilities corresponding to each of these network layers.
  • L4: Layer four is the transport layer. Server load balancers on this layer direct network traffic based on IP address, TCP port numbers, and other transport layer data.
  • L7: Layer seven is known as the application layer. These load balancers can make routing choices based on HTTP headers, SSL session ID, HTML form data, and actual message contents.
  • Global server: Many networks consist of servers in various physical locations. Global server load balancing extends your network's L4 and L7 capabilities to reach them, no matter where they're located.
As with the methods discussed above, you can select load balancing capabilities depending on your network's needs.

Benefits of a Server Load Balancer

Working with a managed IT services provider to add a load balancing server can greatly improve your network's user experience. Here are five of the ways load balancing can benefit your business's network.

1. Secure

Cloud-based computing has become increasingly standard. Unfortunately, distributed denial-of-service (DDoS) attacks have increased along with it.
Load balancers help to prevent this cybercrime more efficiently and at a lower cost than many hardware solutions.
When a DDoS attack comes in, the load balancing server can divert that specific traffic from your business network to a public cloud. This offloading function protects your network from harm without the need for a perimeter firewall.

2. Reliable

In a non-load balanced network, server failure can have disastrous consequences. Luckily, load balancing provides failover protection. If one server goes down, another one immediately takes over without any outages or data loss.

3. Manageable

If your network isn't load-balanced, your servers will have to undergo maintenance on a live system. This can lead to downtime due to network outages. A load balancing server works behind the scenes, so you can perform maintenance without disrupting the network. Your IT team will thank you—it makes upgrades and testing much easier.

4. Flexible and Scaleable

As your business grows and changes, so will the user demand on your network. Each server can only handle a limited amount of traffic, and more servers have to be added in order to increase your network's capacity. With a load-balanced database solution, servers can be added or removed dynamically in response to traffic spikes. This can be done without experiencing downtime or having to change your existing systems.

5. Fast and Efficient

Speed and responsiveness are important parts of the user experience. Load balancing prevents server overload to make sure your network stays fast and reliable, no matter where or when users connect to it.

Load Balancing for Your Business

Investing in a load balancing server is a great step toward improving your business's network. However, it's only one part of a well-managed digital infrastructure. That's why Databerry provides a wide variety of IT services along with consulting—so that your business's online presence can get the personalized attention it needs. Whether you need a CMS upgrade, a marketing overhaul, or a load balancing assessment, we've got you covered. No matter how large or small your business is, Databerry is committed to helping your website become the best it can be. To find out more about which managed IT solutions are right for you, contact us today.
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