Amazon ELB

Application Request Routing (ARR) is an advanced extension for Internet Information Services (IIS) that enables an IIS server to function as a powerful and flexible load balancer. It goes beyond simple traffic distribution by offering content-based routing, allowing administrators to direct requests based on HTTP headers, URL parameters, and server variables. ARR supports various load balancing algorithms and provides features like health monitoring, session persistence, and SSL offloading. Its integration with IIS makes it particularly useful in Windows Server environments, allowing for sophisticated traffic management in web farms and distributed applications. ARR can also act as a reverse proxy, enabling scenarios like caching and request preprocessing.

Azure Front Door is Microsoft's global, scalable entry-point service that enhances the performance, reliability, and security of web applications. It combines global load balancing, multi-region failover, caching, and web application firewall (WAF) capabilities into a single network-as-a-service solution. Front Door uses Microsoft's global edge network to route traffic to the fastest and most available application backend. It offers features like SSL offloading, session affinity, and URL-based routing, making it suitable for both static and dynamic content. Front Door's integration with Azure services and its ability to accelerate and protect applications make it a powerful tool for businesses operating at a global scale.

Amazon Application Load Balancer (ALB) is a feature-rich load balancing service that operates at the application layer (Layer 7) of the OSI model. It goes beyond simple traffic distribution by offering content-based routing, which allows routing requests to different target groups based on the content of the request. ALB supports advanced features like host-based and path-based routing, HTTP/2 and WebSocket protocols, and integration with other AWS services like AWS WAF and AWS Certificate Manager. It provides health checks, automatic scaling, and detailed access logs, making it an ideal choice for modern, microservices-based applications deployed in the AWS cloud.