How to Implement Cross-Region Distributed Tracing with AWS X-Ray?

DVA-C02 By islever Editorial Last updated Aug 8, 2026

Short answer

B Use Region annotation that X-Ray adds automatically for AWS services. Add Region annotation for user-defined services.

Question

A company has an application that runs across multiple AWS Regions. The application is experiencing performance issues at irregular intervals. A developer must use AWS X-Ray to implement distributed tracing for the application to troubleshoot the root cause of the performance issues. What should the developer do to meet this requirement?

Use the X-Ray console to add annotations for AWS services and user-defined services.
Use Region annotation that X-Ray adds automatically for AWS services. Add Region annotation for user-defined services. Correct Answer
Use the X-Ray daemon to add annotations for AWS services and user-defined services.
Use Region annotation that X-Ray adds automatically for user-defined services. Configure X-Ray to add Region annotation for AWS services.

Key Takeaways

The trap is forgetting that only AWS services get automatic Region annotations; custom services require the developer to add the annotation via SDK instrumentation.

For the DVA-C02 exam, this question covers AWS X-Ray annotations for cross-region tracing. Community consensus confirms that X-Ray automatically adds Region annotations for AWS services, while user-defined services must be instrumented manually.

Common mistake: Choosing A or C, assuming the X-Ray console or daemon can add Region annotations. Actually, Region annotations for user-defined services must be added in code using the X-Ray SDK, while AWS services are annotated automatically.

Expert Analysis

Why the Answer Is Correct

X-Ray's cross-region support automatically adds Region annotations for AWS services, as stated in the FAQ. For user-defined services (custom applications, microservices), the developer must instrument the SDK to add the Region annotation. Option B exactly matches this requirement: automatic for AWS services, manual for user-defined ones. High vote count (100% B) and comments reinforce this.

Why the Other Options Are Wrong

Option A says to use the X-Ray console to add annotations, but annotations are configured via SDK instrumentation, not the console. Option C suggests the X-Ray daemon adds annotations, but the daemon only relays data; it doesn't add service annotations. Option D reverses the roles: it claims X-Ray automatically adds Region for user-defined services and requires configuration for AWS services, which is false.

Community Comment Notes

Comments [1] and [3] provide the key evidence: user-defined services must be instrumented in the SDK, and the AWS FAQ confirms automatic Region annotation for AWS services. Comment [2] defines user-defined services clearly, helping distinguish them from AWS-managed services. The high number of upvotes (4, 3, 2) indicates strong community agreement.

Official Reference

These links open the official vendor documentation in a new tab.

Exam Strategy

Remember the asymmetry: AWS services are automatically Region-annotated, but your own code must explicitly set the Region annotation in the X-Ray SDK. On exam day, eliminate options that mention console or daemon for annotations, as those are not used for service annotations.

Community Votes

100%

100% of anonymous learners picked answer B. Votes are pick records left by other test-takers — they are not the verified answer.

Discussion 4 contributions

Compiled from public community threads and reader submissions, lightly edited for clarity. Handles and vote tallies are shown as recorded, and comments reflect the views of individual contributors.

From public community threads 4

CrescentShared 👍 4 Answered B

User defined has to be in sdk.
Abdullah22 👍 3 Answered B

User-defined services: Developed by users: These services are applications, microservices, or any software components specifically built and deployed by the user or organization using AWS. They can be written in any programming language and deployed on various platforms, including EC2 instances, Lambda functions, or containers on platforms like Amazon ECS or EKS.
KarBiswa 👍 2 Answered B

https://aws.amazon.com/xray/faqs/#:~:text=Region%20annotation%20for%20AWS%20services%20will%20be%20added%20automatically%2C%20however%2C%20customers%20will%20need%20to%20instrument%20custom%20services%20to%20add%20the%20regional%20annotation%20to%20make%20use%20of%20the%20cross%2Dregion%20support.
65703c1 👍 1 Answered B

B is the correct answer.

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