What is Load Balancing? - Definition & Meaning
Learn what load balancing is, how traffic is distributed across servers, and why it is essential for scalability and high availability.
Definition
Load balancing is the distribution of incoming network traffic across multiple servers to spread the workload evenly. This improves the availability, reliability, and performance of applications.
Technical explanation
Load balancers operate at different OSI layers: Layer 4 (transport) distributes traffic based on IP and TCP/UDP port, while Layer 7 (application) makes content-aware decisions based on HTTP headers, URL paths, or cookies. Common algorithms include round-robin (distributing requests evenly), least connections (routing to the server with fewest active connections), weighted round-robin (servers with more capacity receive more traffic), and IP hash (consistent routing based on client IP). Health checks continuously monitor backend server health; unhealthy servers are automatically removed from the pool. Session persistence (sticky sessions) ensures a user is always routed to the same server. NGINX and HAProxy are popular software-based load balancers. Cloud providers offer managed solutions such as AWS ALB/NLB, Google Cloud Load Balancer, and Azure Load Balancer. SSL termination at the load balancer reduces cryptographic overhead on backend servers. Auto-scaling groups coupled with load balancers automatically add or remove servers based on traffic.
How MG Software applies this
MG Software implements load balancing across all client production environments. We use NGINX as a reverse proxy and load balancer for web applications, and cloud-native load balancers with Vercel and AWS. This ensures our client applications remain available during traffic spikes and maintenance windows.
Practical examples
- A news website using NGINX round-robin load balancing during breaking news to distribute traffic across ten application servers, serving millions of concurrent visitors.
- A SaaS platform using AWS Application Load Balancer to route API requests to the correct microservice based on URL path.
- An e-commerce site using weighted load balancing to send more traffic to newer, more powerful servers during a gradual migration.
Related terms
Frequently asked questions
Related articles
Monolith vs Microservices: Complete Comparison Guide
Compare monolithic and microservice architectures on scalability, complexity, deployment, and team structure. Discover which architecture fits your project.
Multi-tenant Architecture Examples - Inspiration & Best Practices
Discover multi-tenant architecture examples and learn how SaaS companies combine scalability with data isolation. Database-per-tenant, shared schema, and more.
What is an API? - Definition & Meaning
Learn what an API (Application Programming Interface) is, how it works, and why APIs are essential for modern software development and system integrations.
What is SaaS? - Definition & Meaning
Discover what SaaS (Software as a Service) means, how it works, and why more businesses are choosing cloud-based software solutions for their operations.