Question 1mediummultiple choice
Full question →mediummultiple choiceObjective-mapped
A company uses AWS CodeDeploy to deploy a web application to an Auto Scaling group of EC2 instances. The deployment must automatically roll back if the new application version causes health check failures for more than 20% of the instances within the first 5 minutes after deployment. Which configuration should the developer set in the deployment group?
Answer choices
Why each option matters
Good practice is not just finding the correct option. The wrong answers often show the exact trap the exam wants you to fall into.
A
Best answer
Create a CloudWatch alarm that monitors the DeploymentFailure metric and configure it as a rollback trigger in the deployment group.
This is the correct method. CodeDeploy can use CloudWatch alarms as rollback triggers. When the alarm enters the ALARM state, the deployment is automatically rolled back.
B
Distractor review
Define a lifecycle hook in the Auto Scaling group that terminates instances with failing health checks.
Lifecycle hooks allow you to pause instance launch or termination for custom actions, but they do not automatically roll back a deployment.
C
Distractor review
Set the deployment configuration to use a minimum healthy host percentage of 80% and a timeout of 5 minutes.
This only controls how many instances must remain healthy during the deployment. It does not automatically roll back if health checks fail after the deployment completes.
D
Distractor review
Configure the AppSpec file with a rollback section that specifies the health check failure threshold.
The AppSpec file does not have a rollback section. Rollback settings are configured in the deployment group, not in the AppSpec.
Common exam trap
Common exam trap: NAT rules depend on direction and matching traffic
NAT is not only about the public address. The inside/outside interface roles and the ACL or rule that matches traffic are just as important.
Technical deep dive
How to think about this question
NAT questions usually test address translation, overload/PAT behaviour, static mappings and whether the right traffic is being translated. Read the interface direction and address terms carefully.
KKey Concepts to Remember
- Static NAT maps one inside address to one outside address.
- PAT allows many inside hosts to share one public address using ports.
- Inside local and inside global describe the private and translated addresses.
- NAT ACLs identify traffic for translation, not always security filtering.
TExam Day Tips
- Identify inside and outside interfaces first.
- Check whether the scenario needs static NAT, dynamic NAT or PAT.
- Do not confuse NAT matching ACLs with normal packet-filtering intent.
Related practice questions
Related DVA-C02 practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
More questions from this exam
Keep practising from the same exam bank, or move into a focused topic page if this question exposed a weak area.
Question 1
A developer is building a REST API using Amazon API Gateway that will serve static content from an Amazon S3 bucket. The API should cache responses for frequently accessed objects to reduce latency. Which API Gateway feature should the developer enable?
Question 2
A developer is running a web application on multiple Amazon EC2 instances behind an Application Load Balancer (ALB). The application needs to store user session state that must be available across all instances. The session data is small and temporary but must survive individual instance failures. Which AWS service should the developer use to store this session state?
Question 3
A developer has an AWS Lambda function that processes messages from an Amazon SQS standard queue. The function is idempotent and currently has a batch size of 10. The developer wants to increase throughput and increases the batch size to 100. After the change, CloudWatch metrics show a significant increase in throttles and the queue backlog is growing. The function's reserved concurrency is set to 10. What is the most effective action to resolve the throttling and improve throughput?
Question 4
A developer is managing an application running on Amazon EC2 instances behind an Application Load Balancer. Users report that the application becomes unresponsive after several hours, and restarting the instance temporarily fixes the issue. The developer suspects a memory leak but cannot add custom instrumentation. Which AWS service can collect memory utilization metrics and help identify the memory leak with minimal configuration?
Question 5
A developer is building a serverless web application using AWS Lambda and Amazon DynamoDB. The application needs to perform complex aggregations on data stored in DynamoDB. Which AWS service should the developer use to perform these aggregations efficiently without reading all the data into Lambda?
Question 6
A developer has an Amazon S3 bucket containing private user documents. The application must generate a time-limited URL for users to download their own documents without requiring the users to have AWS credentials. Which solution should the developer use?
FAQ
Questions learners often ask
What does this DVA-C02 question test?
Static NAT maps one inside address to one outside address.
What is the correct answer to this question?
The correct answer is: Create a CloudWatch alarm that monitors the DeploymentFailure metric and configure it as a rollback trigger in the deployment group. — To automatically roll back a deployment when health checks fail, the developer should configure the rollback trigger under the deployment group settings. Specifically, they need to enable automatic rollback and set a CloudWatch alarm that triggers when the deployment fails (e.g., using the DeploymentFailure alarm). Alternatively, they can configure the deployment to roll back based on the failure threshold and time limit. In CodeDeploy, you can set a rollback trigger by specifying a CloudWatch alarm that monitors the deployment's health. The correct answer is to create a CloudWatch alarm that monitors the DeploymentFailure metric and use it as a rollback trigger. Option B (setting a lifecycle hook) is incorrect because lifecycle hooks are for custom actions during instance launch/terminate, not for rollback. Option C (using a deployment configuration with a minimum healthy host percentage) controls the speed of deployment but does not automatically roll back. Option D (enabling the rollback configuration in the AppSpec file) is incorrect because the AppSpec file defines hooks and files, not rollback triggers.
What should I do if I get this DVA-C02 question wrong?
Then try more questions from the same exam bank and focus on understanding why the wrong options are tempting.
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