The correct answer is to configure the alias with a canary deployment and an error rate alarm for automatic rollback. This works because AWS CodeDeploy manages the traffic shift for the Lambda alias, and when you attach a CloudWatch alarm based on the error rate, CodeDeploy automatically triggers a rollback to the previous version the moment the alarm breaches, preventing further impact without any manual intervention. On the AWS Certified Developer Associate DVA-C02 exam, this scenario tests your understanding of safe deployment strategies—specifically how Lambda alias blue/green rollback can be automated using CodeDeploy’s canary or linear traffic shifting combined with CloudWatch alarms. A common trap is to think you must manually revert the alias or delete the new version, but the exam emphasizes automated, low-risk responses. Memory tip: think “Canary + Alarm = Auto-Rollback,” where the canary catches errors early and the alarm pulls the trigger.
DVA-C02 Troubleshooting and Optimization Practice Question
This DVA-C02 practice question tests your understanding of troubleshooting and optimization. Match the stated requirement to the specific cloud service, access model, or configuration option — many options are valid in isolation but not for this scenario. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
A developer is deploying a new version of a Lambda function using an alias for blue/green deployment. Traffic is gradually shifted to the new version. During the shift, a high error rate is observed. What should the developer do to minimize impact?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue: "minimum / minimize"
Why it matters: Asks for the least resource use — fewest addresses, smallest subnet, lowest overhead. Eliminate over-provisioned options even if they would technically work.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Configure the alias with a canary deployment and an error rate alarm for automatic rollback.
Option C is correct because it automates the rollback process using AWS CodeDeploy's canary deployment with an Amazon CloudWatch alarm on the error rate. When the alarm triggers, CodeDeploy automatically shifts traffic back to the previous version, minimizing impact without manual intervention. This is the recommended approach for safe blue/green deployments with Lambda aliases.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✗
Use the Lambda function's provisioned concurrency to pre-warm the new version.
Why it's wrong here
Provisioned concurrency reduces cold starts but does not handle automatic rollback.
✗
Manually revert the alias to point back to the old version.
Why it's wrong here
Manual rollback is slower and error-prone; automation is better.
✓
Configure the alias with a canary deployment and an error rate alarm for automatic rollback.
Why this is correct
Canary deployment with alarm-based rollback minimizes impact.
Clue confirmation
The clue word "minimum / minimize" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
✗
Delete the new version and redeploy after fixing the issue.
Why it's wrong here
Deleting may cause downtime; gradual rollback is preferred.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates may think manual reversion (Option B) is the simplest fix, but the exam emphasizes automated rollback strategies (like canary deployments with alarms) as the best practice for minimizing impact during blue/green deployments.
Detailed technical explanation
How to think about this question
Under the hood, AWS CodeDeploy uses a weighted alias to gradually shift traffic between two Lambda function versions. When you configure a canary deployment with a CloudWatch alarm, CodeDeploy monitors the error rate metric (e.g., `Errors` or `Throttles`) and, if the alarm breaches the threshold, it automatically updates the alias to point 100% to the previous version. This leverages the Lambda alias routing configuration, which supports up to two versions with traffic weights that sum to 100%.
KKey Concepts to Remember
Read the scenario before looking for a memorised answer.
Find the constraint that changes the correct option.
Eliminate answers that are true in general but not in this case.
TExam Day Tips
→Watch for words such as best, first, most likely and least administrative effort.
→Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A cloud solutions architect for a retail company is evaluating services for a new workload. The correct answer here reflects best practice for the specific scenario described — not a general cloud recommendation. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Cloud exam questions reward reading the constraint carefully: the same technology can be right or wrong depending on the use case.
What to study next
Got this wrong? Here's your next step.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Troubleshooting and Optimization — This question tests Troubleshooting and Optimization — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Configure the alias with a canary deployment and an error rate alarm for automatic rollback. — Option C is correct because it automates the rollback process using AWS CodeDeploy's canary deployment with an Amazon CloudWatch alarm on the error rate. When the alarm triggers, CodeDeploy automatically shifts traffic back to the previous version, minimizing impact without manual intervention. This is the recommended approach for safe blue/green deployments with Lambda aliases.
What should I do if I get this DVA-C02 question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Are there clue words in this question I should notice?
Yes — watch for: "minimum / minimize". Asks for the least resource use — fewest addresses, smallest subnet, lowest overhead. Eliminate over-provisioned options even if they would technically work.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
About these practice questions
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These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. A developer deployed a new version of a Lambda function using an alias that points to the new version. However, the function continues to invoke the old version. What is the MOST likely cause?
medium
A.The IAM execution role for the Lambda function does not have permission to invoke the new version.
✓ B.The alias was not updated to point to the new version after deployment.
C.The Lambda function's reserved concurrency is set to 0, preventing new invocations.
D.The function name in the invocation request is different from the deployed function.
Why B: Option B is correct because if the version number in the alias is not updated, the alias still points to the old version. Option A (concurrency) does not affect which version is invoked. Option C (different function name) would cause a different error. Option D (IAM permissions) would cause access denied errors, not invocation of old code.
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This DVA-C02 practice question is part of Courseiva's free Amazon Web Services certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the DVA-C02 exam.
Question Discussion
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