As the digital landscape expands and the number of users accessing software applications and systems over the Internet, at any given second multiplies, managing application traffic has become a critical aspect of ensuring optimal system performance.
Load balancing can be traced back to the 1990s. With the advent of client-server architecture, the need for a mechanism to distribute network traffic to avoid server overloads was realized. Initially, it was achieved using simple algorithms like Round-Robin, which distributed requests sequentially to servers in an endless loop.
As the internet grew exponentially, load balancing techniques matured to cope with increasing web traffic. Hardware-based load balancers, also known as Application Delivery Controllers (ADCs), were introduced and could handle higher traffic. However, they were expensive and inflexible.
The evolution of cloud computing in the mid-2000s brought about a paradigm shift in load balancing. Software-defined load balancers emerged which offered the much-needed flexibility, scalability, and cost-effectiveness. They could easily adjust to fluctuations in traffic and were accessible even to small companies due to their low cost.
The latest generation of ADCs handle a much wider variety of functions, which play crucial roles in managing, scaling, optimizing and securing communication between clients and servers. Modern ADCs include capabilities beyond just a load balancer, like reverse proxy and API gateway. At first glance, they might seem interchangeable – they all sit between a web client and the server and can distribute requests to different servers. While they do have some functionality overlaps, they’re distinct tools with different purposes and use cases.
The primary role of a load balancer is to distribute traffic across backend servers. The main purpose of a reverse proxy is to improve performance and security of web traffic, while the focus of an API gateway is to manage and secure API traffic.