Load balancing is a critical component of modern web infrastructure, enabling websites and applications to handle high traffic volumes efficiently and reliably. By distributing incoming network traffic across multiple servers, load balancers ensure optimal resource utilisation, improved responsiveness, and enhanced fault tolerance. Let's explore how load balancing works in practice and examine some real-world success stories.
How Load Balancing Works?
At its core, load balancing involves distributing incoming requests across a group of backend servers, also known as a server pool or server farm. When a client sends a request, the load balancer intercepts it and forwards it to one of the available servers based on a predefined algorithm. Some common load balancing algorithms include:
- Round Robin: Requests are distributed sequentially to each server in turn.
- Least Connections: Requests are sent to the server with the fewest active connections.
- IP Hash: The client's IP address is used to determine which server receives the request.
- Weighted Round Robin: Servers are assigned different weights based on their capacity.
Each algorithm has its strengths and is suited for different scenarios. For example, round robin is simple and works well when all servers have similar capabilities, while least connections can be more effective when server loads vary significantly.
Scenario: E-commerce Platform
Imagine an e-commerce platform experiencing rapid growth. As the number of daily visitors increases, the single server that once handled all traffic begins to struggle. Response times slow down, and during peak shopping periods, the site becomes unresponsive.
To address this, the company implements a load balancing solution:
- They set up multiple identical web servers, each capable of handling customer requests.
- A load balancer is placed in front of these servers.
- The load balancer uses a least connections algorithm to distribute incoming traffic.
Thus, during the next major sale and the site experiences an increase in traffic, here are the things what the load balancer will do to ensure the website performs seamlessly:
- Traffic is evenly distributed across all servers.
- No single server becomes overwhelmed.
- The site remains responsive even during peak hours.
- If one server fails, traffic is automatically rerouted to healthy servers.
Real-Life Success: Load Balancing Solutions
Here are real-life case studies from prominent companies and universities that you may be familiar with, showcasing how they have successfully implemented load balancing to optimise their IT infrastructure and achieve remarkable results.
GitHub

GitHub, the popular code hosting platform, leverages load balancing to ensure high availability and performance for millions of developers worldwide. Their infrastructure includes:
- Global Load Balancing: GitHub uses Anycast routing to direct users to the nearest data centre.
- Layer 4 Load Balancing: Within each data centre, Layer 4 load balancers distribute traffic across multiple application servers.
- Layer 7 Load Balancing: Application-level load balancers handle specific features like authentication and Git operations.
- Database Load Balancing: GitHub uses custom load balancing solutions for their MySQL database clusters.
This multi-tiered approach allows GitHub to handle massive amounts of traffic, including large-scale DDoS attacks, while maintaining excellent performance and reliability.
Texas A&M University
Texas A&M University, one of the largest universities in the United States with 50,000 students, implemented load balancing solutions for its Provost IT Office (PITO). Key points:
- PITO maintains IT assets and services for approximately 40 different departments, including admissions, financial aid, registrar, career placement, and study abroad student services.
- The university deployed load balancers to address the challenges of accommodating peak loads, ensuring fast end-user response times, and securing information and applications.
- The solution helped optimise current assets while introducing new applications and services, providing increased capacity and enabling cost-effective, flexible scaling as demand grows.

Airbnb

Airbnb, the popular online marketplace for lodging and tourism experiences, relies heavily on load balancing to handle its massive global traffic and ensure a smooth user experience.
Airbnb's load balancing strategy includes:
- Global Traffic Management: Airbnb uses Amazon Route 53 for DNS-based global traffic management, directing users to the nearest available data center.
- Application Load Balancing: Within each data center, Airbnb employs Elastic Load Balancers (ELBs) to distribute traffic across multiple application servers.
- Dynamic Scaling: Airbnb's infrastructure automatically scales up or down based on traffic patterns, ensuring optimal resource utilization.
- Service Mesh: For internal microservices communication, Airbnb uses a service mesh architecture with built-in load balancing capabilities.
- Database Load Balancing: Airbnb has developed a custom solution called "Dynein" for load balancing MySQL database queries.

The results of this comprehensive approach are impressive:
- Airbnb can handle over 1 million searches per second during peak times.
- The platform maintains sub-second response times for most operations.
- Even during major events like New Year's Eve, when bookings spike dramatically, the system remains stable and responsive.
Spotify

Spotify, the world's leading music streaming service, uses an innovative load balancing approach to deliver a seamless listening experience to its 350+ million users.Spotify's load balancing infrastructure includes:
- Content Delivery Network: Spotify uses a combination of its own CDN and third-party CDNs to cache and serve audio content from locations close to users.
- Microservices Architecture: Spotify's backend is composed of hundreds of microservices, each with its own load balancing requirements.
- Custom Load Balancer: Spotify developed its own Layer 7 load balancer called "Skipper" to handle routing between microservices.
- Adaptive Bitrate Streaming: Spotify's client applications use adaptive bitrate streaming, which can be considered a form of client-side load balancing, adjusting audio quality based on network conditions.
- Data Center Load Balancing: Spotify uses Google Cloud Platform's global load balancing to distribute traffic across its data centers worldwide.

The benefits of this approach include:
- Low latency audio streaming, with most songs starting to play in under 200 milliseconds.
- High availability, with the service maintaining 99.99% uptime.
- Ability to handle massive traffic spikes, such as when popular artists release new albums.
Netflix

Netflix, the streaming giant, serves millions of users worldwide and relies heavily on load balancing to ensure a smooth viewing experience. Their approach to load balancing is particularly interesting and effective.
Netflix uses a combination of DNS-based global load balancing and application-level load balancing:
- Global Load Balancing: When a user attempts to stream content, Netflix's DNS system directs them to the nearest content delivery network (CDN) point of presence.
- Application-Level Load Balancing: Within each CDN location, application-level load balancers distribute requests across multiple servers.
- Adaptive Load Balancing: Netflix's system continuously monitors server health and performance, adjusting traffic distribution in real-time.
- Predictive Scaling: Using machine learning algorithms, Netflix predicts traffic patterns and scales its infrastructure accordingly.
This multi-layered approach allows Netflix to handle massive traffic spikes, such as during the release of popular shows, while maintaining high availability and low latency for users worldwide.
University of Northampton
The University of Northampton implemented load balancing appliances to improve the performance and resilience of its IT systems. Key points:
- The university installed Kemp load balancing appliances to enhance its Library Services authentication for students.
- The solution also supports Microsoft Exchange 2010 Servers, serving a staff of over 2,000.
- By implementing load balancing, the university improved the reliability and performance of critical services for both students and staff.

Overt Software Solutions: Supporting Your Load Balancing Needs
Managing a robust load balancing infrastructure can be complex, but it’s essential for modern organisations to maintain seamless operations. If you need assistance with implementing or optimising your load balancing solutions, Overt Software Solutions is here to help. With our expertise in IT infrastructure, we provide tailored, reliable solutions that align with your unique requirements. Contact us today to learn more about our services and support.