Application Load Balancing
Application Load Balancing is a networking service that distributes incoming application traffic across multiple targets, such as EC2 instances, containers, or IP addresses, in one or more Availability Zones. It operates at the application layer (Layer 7) of the OSI model, enabling content-based routing, SSL/TLS termination, and health checks to ensure high availability and fault tolerance for web applications. This technology is commonly used in cloud environments to optimize resource utilization and improve user experience by directing requests to the most appropriate backend servers.
Developers should learn and use Application Load Balancing when building scalable, highly available web applications, especially in cloud-based or microservices architectures, as it handles traffic spikes, prevents server overload, and provides seamless failover during outages. It is essential for applications requiring features like HTTP/HTTPS routing, session persistence, or integration with auto-scaling groups, such as e-commerce sites, APIs, and content delivery networks, to maintain performance and reliability under varying loads.