AWS Certified SysOps Administrator Practice Exam

What is a key consideration when using AWS X-Ray with Application Load Balancers?

1. Application Load Balancers send trace data to X-Ray by default.

2. Application Load Balancers do not emit trace data to X-Ray.

3. Using X-Ray requires you to disable the Application Load Balancer.

4. X-Ray is only compatible with API Gateway and EC2 instances.

The correct answer is: Application Load Balancers do not emit trace data to X-Ray.

When using AWS X-Ray with Application Load Balancers, it is important to understand that Application Load Balancers do not automatically emit trace data to X-Ray. This means that trace data must be handled and sent from the underlying application that is running behind the load balancer. In order to leverage X-Ray for monitoring and debugging, the developer must instrument their application code to send the appropriate trace information to X-Ray, typically utilizing the AWS SDKs or the X-Ray SDK. This design allows for granular control over tracing and debugging, as the application itself is responsible for generating the trace data that X-Ray processes. Since Application Load Balancers sit at a layer that primarily manages routing and distribution of incoming requests without incorporating business logic, they do not capture or relay trace data on their own. Understanding this characteristic helps architects and developers design their applications effectively to get the benefits of X-Ray while working with load balancers, ensuring they handle distributed tracing appropriately at the application level.