AWS Certified SysOps Administrator – Associate (legacy) — Question 735

A SysOps administrator has set up a new public Application Load Balancer (ALB) in front of a pair of private web servers in multiple Availability Zones. After deploying an updated AWS CloudFormation template with many changes, user traffic now goes to one web server only.
What is the MOST likely reason that the traffic is not being balanced between both servers?

Answer options

• A. The faulty server is returning HTTP 200 codes and has been removed.
• B. Sticky sessions have been disabled in the ALB for the working server.
• C. The ALB is using a custom ping path that is not found on the faulty server.
• D. The web clients are using HTTP/2, which is terminated at the ALB.

Correct answer: A

Explanation

If the CloudFormation update modified the target group's health check settings to expect a specific non-200 status code (such as a redirect), any server returning an HTTP 200 code would be marked unhealthy and removed from the routing pool. Disabling sticky sessions would actually improve traffic distribution rather than restricting it to a single server. HTTP/2 termination at the ALB does not impact backend load balancing mechanisms.