Application Load Balancer
Application Load Balancer (ALB) is a Layer 7 load balancer service provided by AWS that distributes incoming application traffic across multiple targets, such as EC2 instances, containers, and IP addresses, based on advanced routing rules. It operates at the application layer (HTTP/HTTPS) and supports features like path-based routing, host-based routing, and integration with AWS services like Lambda and ECS. ALB is designed to handle the demands of modern microservices and container-based architectures by providing high availability, automatic scaling, and security features.
Developers should use Application Load Balancer when building scalable web applications, APIs, or microservices on AWS that require intelligent traffic routing, SSL/TLS termination, or integration with serverless components. It is particularly useful for applications with dynamic scaling needs, such as those using containers (ECS/EKS) or serverless functions (Lambda), where ALB can route requests based on content like URL paths or host headers. ALB also enhances security by offloading SSL/TLS processing and integrating with AWS WAF for web application firewall protection.