Do we need a load balancer when following a microservices architecture

Question

Do we need a load balancer when following a microservices architecture?

Sarthak Varshney · Answer

Yes, a load balancer is often needed in a microservices architecture because it helps manage traffic efficiently. Microservices typically have multiple instances of the same service running to handle more users or requests. A load balancer ensures that these requests are spread evenly across all instances, so no single one gets overloaded. For example, imagine an online shopping app where users browse products and place orders. If 100 users send requests at the same time, a load balancer will distribute these requests among, say, 5 instances of the "product service" and 3 instances of the "order service." This way, all requests are handled quickly, and no instance crashes due to too much traffic. Additionally, if one instance fails (e.g., a server crashes), the load balancer will detect this and send traffic to the healthy instances instead. This ensures that users don’t experience downtime. A load balancer might be unnecessary in small systems with only one instance per service. But as the system grows and traffic increases, a load balancer becomes crucial for keeping the system fast, reliable, and scalable. Tools like NGINX , AWS Elastic Load Balancer , or Kubernetes Ingress are commonly used for this purpose.