Load Balancer

A load balancer is a tool that efficiently distributes incoming requests among multiple instances of an application. Take a microservice architecture for example, where each service can be scaled horizontally. A load balancer sits in front of a scaled microservice and ensures that no one instance gets the bulk of the requests. Load balancers can be software or hardware-based.

Problem it addresses

Modern applications and websites generally serve hundreds of thousands of simultaneous end-user requests. To handle all those requests, applications are often scaled horizontally. But horizontal scaling introduces a new challenge. How do you distribute incoming traffic to all services equally? This is where load balancers come in.

How it helps

Load balancers dynamically distribute all incoming requests among multiple services, ensuring that no one service gets the bulk of it while others only get a few or none. In short, it spreads the load across multiple services, following a defined schema (i.e., evenly or percentage-based). Load balancers are essential to an application’s overall performance and, ultimately, the user experience.