Amazon ALB

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.

Amazon Elastic Load Balancing (ELB) is a comprehensive load balancing service provided by AWS that automatically distributes incoming application traffic across multiple targets. ELB offers three types of load balancers: Application Load Balancer (ALB) for HTTP/HTTPS traffic, Network Load Balancer (NLB) for TCP/UDP traffic, and Classic Load Balancer for basic load balancing. ELB can distribute traffic to various AWS resources including EC2 instances, containers, and Lambda functions. It provides features like health checks, SSL/TLS termination, and integration with other AWS services. ELB's ability to automatically scale and its high availability design make it a crucial component for building fault-tolerant and scalable applications in the AWS cloud.

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.