How load balancing works

Posted by Admin | 1 September, 2022 | Technical

Load balancing is a prevalent practice within the realm of computing, originating from the demand for rapid content access by users. As a result, high-traffic websites receiving millions of user requests had to innovate and devise efficient methods for swift content delivery. But what exactly is load balancing, and what are its benefits?

This blog will talk about load balancing, what it is, its functions, and its benefits.

Load Balancing Definition

Load balancing involves directing network traffic among a group of servers or server farms, where a load balancer can take the form of either a software or hardware device. Its primary purpose is to prevent server overload caused by incoming traffic by intelligently distributing it across other servers.

As your company experiences growth, its user base naturally expands, necessitating the scaling of resources to accommodate increased user requests. This typically involves the addition of more servers to the server farm.

You could liken a load balancer to a vigilant traffic officer positioned in front of your servers, responsible for allocating client requests to servers capable of handling them. This orchestration ensures the prompt distribution of requests while preventing any single server from becoming overwhelmed.

Should one server become inaccessible, the load balancer seamlessly redirects traffic to the remaining online servers. Furthermore, as you incorporate new servers into the server farm, the system automatically begins distributing traffic to them as well.

How Load Balancing has Evolved

Before the advent of load balancers, networks relied on physical server farms to manage the increasing volume of traffic. These hardware-based server load balancers played a crucial role in ensuring the availability of applications to users.

The initial load balancers were hardware devices equipped with straightforward algorithms designed to direct requests to the appropriate servers. Their primary function was to evenly distribute incoming requests among the available machines.

Over time, the web landscape grew more intricate, marked by a dramatic surge in the number of users, computers, and network devices. This resulted in a higher volume of complex and frequent requests. Load balancers had to adapt and extend their capabilities beyond mere request distribution to consider other factors like geographical location when routing traffic.

In response, developers delved into methods for analyzing HTTP headers to determine the appropriate actions for load balancers to take. They began scrutinizing layer 7 header information, enabling load balancers to make more informed decisions and enhance network performance optimization.

What Functions Does a Load Balancer Do?

The load balancer assumes a critical role by accomplishing the following tasks:

Efficiently distributes requests across all servers.
Routes requests to online servers, ensuring exceptional availability and reliability.
Facilitates the addition or removal of servers as required.

Now that we’ve explored the load balancer’s functions, let’s delve into its algorithms to understand how load balancing operates.

What is a Load Balancing Algorithm?

As previously explained, a load balancer serves as a device to prevent your servers from becoming overwhelmed by incoming traffic. It can take the form of either software or hardware, with hardware being the predominant choice in earlier load balancers.

A load balancing algorithm is a set of procedures or rules employed by a load balancer to apportion network traffic among servers. There are two primary types of load balancing algorithms, each offering distinct advantages: Dynamic load balancing and Static load balancing. These categories encompass various specific algorithms.

Dynamic load balancing relies on algorithms or rules that take into account the real-time status of each server before distributing traffic accordingly. In contrast, Static load balancing does not factor in the current state of each server. Some algorithms within this category evenly distribute traffic among all servers.

Selecting the most suitable algorithm depends on your specific requirements. Now, let’s delve deeper into the details of these two types of algorithms below.

Dynamic Load Balancing Algorithms

Here are descriptions of various dynamic load balancing algorithms:

Least Connections
The least connections algorithm evaluates the computing capacity of each server and identifies those with the fewest active connections. It then directs traffic to these servers, aiming to distribute the load evenly.

Weighted Least Connection
This algorithm is particularly useful when some servers possess greater computing capacity than others. It empowers administrators to assign varying traffic levels to each server. Servers with higher computing power can handle more traffic than their less powerful counterparts.

Weighted Response Time
Weighted response time prioritizes user experience by routing traffic to servers with the shortest response times. It takes into account both the number of active connections on each server and the average response time to make informed traffic distribution decisions.

The resource-based algorithm employs specialized software agents to assess the available resources (such as CPU and memory) at the time of a request. It then distributes traffic based on the real-time availability of these resources, ensuring optimal server utilization.

Static Load Balancing Algorithms

Here are descriptions of various static load balancing algorithms:

Round Robin
The round robin algorithm allocates traffic among a server group, either sequentially or in a rotational fashion. Each server takes its turn in servicing requests, ensuring an equitable distribution of workload.

Weighted Round-Robin
This algorithm provides administrators with the capability to designate varying traffic levels to individual servers. Administrators can define the weight or percentage of traffic allocated to each server. This information enables them to determine which servers are better equipped to handle increased traffic loads.

Benefits of Load Balancing

Reduced Downtime
Load balancing effectively mitigates service disruptions. During server maintenance, a load balancer automatically redirects traffic to other available servers, allowing you to perform necessary updates while keeping your users online and unaffected.

Load balancing provides seamless scalability. You can effortlessly expand your server capacity, whether physical or virtual, in response to increased demand. When you add a new server, the load balancer immediately detects it and begins allocating traffic, relieving the load on existing servers and directing it to the newly added one.

Redundancy is a vital aspect of computing, and load balancers excel in this regard. In the event of a server failure, your load balancer swiftly transfers the workload to other operational servers. This minimizes disruptions for users and allows you to address the issue with the failed server without significant impact.

Load balancers optimize efficiency by intelligently distributing traffic to servers with lower loads or higher computing capabilities. Additionally, load balancing grants you the flexibility to add or remove servers as demand fluctuates. You can perform server maintenance without scheduling downtime; simply deactivate a server, and the load balancer seamlessly utilizes your other active servers to maintain uninterrupted service.

How RELIANOID Facilitates Load Balancing

As previously emphasized, load balancing offers indispensable advantages in the realm of computing, primarily ensuring uninterrupted user access and bolstering flexibility.

For those seeking a user-friendly yet cutting-edge load balancer, RELIANOID presents an open-source solution that excels in security and scalability. Notably, its standout feature is its remarkable performance, outpacing cloud vendor alternatives by more than 20 times.

With RELIANOID, concerns regarding availability and automation are put to rest. Take the leap and commence your load balancing journey with RELIANOID today.