Which AWS Service Distributes HTTP Traffic Across EC2 Instances?

Why the Answer Is Correct

The question asks for a service that distributes incoming HTTP traffic evenly across all running EC2 instances. Application Load Balancer (ALB) is a Layer 7 load balancer that natively understands HTTP and HTTPS, so it can inspect requests and spread them across targets in a target group, including EC2 instances. ALB performs health checks and balances traffic across healthy registered instances, which is exactly the stated requirement. It also adds HTTP-specific capabilities such as host-based and path-based routing, sticky sessions, and redirects. Because the protocol named in the question is explicitly HTTP, ALB is the intended match rather than any Layer 4 option.

Why the Other Options Are Wrong

Amazon EC2 Auto Scaling adjusts the number of running instances in response to demand; it adds or removes capacity but does not itself distribute incoming traffic across those instances. Gateway Load Balancer is built to insert third-party virtual appliances such as firewalls and intrusion detection systems into the traffic path using GENEVE at Layer 3/4, so it has nothing to do with HTTP balancing. Network Load Balancer operates at Layer 4 and handles TCP, UDP, and TLS traffic with extreme performance and static IPs, but it does not natively parse HTTP requests. Choosing NLB is the classic trap when a question mentions HTTP; the protocol keyword points to ALB.

Community Comment Notes

Every learner vote in the thread selected B, and the reasoning lines up with the AWS exam blueprint. As CCNP21 noted, "ALB works at Layer 7, meaning HTTPS. NLB works at Layer 4." AravindrajG pointed at the exact trigger phrase, "Keyword: Distribute incoming HTTP traffic evenly across all running instances," and tied it to ALB's Layer 7 support for HTTP. ShaiTay, wmv__ and HappyG simply confirmed B. The unanimous, layer-based rationale reinforces the independent verdict that Application Load Balancer is correct.