DVA-C02 Timed Practice Test 4 — 10 Questions

Question 1

A company uses AWS CodePipeline with CodeBuild to deploy a Node.js application. The build fails intermittently with 'npm ERR! network' errors. What is the most likely cause and solution?

Accepted Answer

The build environment lacks outbound internet access; configure a NAT gateway or use a VPC endpoint for npm.. Option A is correct because CodeBuild may have limited outbound internet access; using a NAT gateway or VPC endpoint for npm registry resolves this. Option B is incorrect because failing test does not cause network errors. Option C is incorrect because CodeBuild does not have npm cache. Option D is incorrect because npm token expiry returns 401, not network errors.

Answer

A unit test is failing; fix the test code.

Answer

The npm cache is corrupted; clear the cache in CodeBuild.

Answer

The npm token has expired; regenerate the token.

Question 2

An organization wants to deploy a microservices architecture using AWS Lambda functions. They need to manage environment variables for each function across different stages (dev, test, prod). Which approach is the MOST secure and maintainable?

Accepted Answer

Use AWS Systems Manager Parameter Store with separate paths for each stage.. Option C is correct because AWS Systems Manager Parameter Store provides secure, hierarchical storage for configuration data. Option A is wrong because hardcoding is insecure. Option B is wrong because environment variables in the function code are not environment-specific. Option D is wrong because CloudFormation parameters are for infrastructure, not runtime config.

Answer

Use AWS CloudFormation parameters to pass values at deployment.

Answer

Hardcode the environment variables in each Lambda function code.

Answer

Store environment variables in the Lambda function configuration.

Question 3

A developer is deploying a serverless application using the AWS Serverless Application Model (SAM). The application consists of an API Gateway endpoint and an AWS Lambda function. The developer wants to define a stage name for the API Gateway deployment. Which section of the SAM template should the developer use?

Accepted Answer

Globals. Option B is correct because the Globals section allows setting properties that apply to all resources, including Api.StageName. Option A is wrong because Outputs are for stack outputs. Option C is wrong because Parameters are for input values. Option D is wrong because Conditions are for conditional resource creation.

Answer

Conditions

Answer

Outputs

Answer

Parameters

Question 4

A company is using AWS CodeBuild to compile and test a Java application. The build takes 15 minutes, but the company wants to reduce build time by caching dependencies. Which file should the developer modify to enable caching in the build project?

Accepted Answer

buildspec.yml. Option B is correct because the buildspec.yml can specify cache.paths to cache directories like .m2. Option A is wrong because pom.xml is for Maven project configuration, not build caching. Option C is wrong because buildspec.json is not a standard file; buildspec.yml is used. Option D is wrong because the CodeBuild console settings can enable cache, but the question asks which *file* to modify.

Answer

CodeBuild console settings

Answer

pom.xml

Answer

buildspec.json

Question 5

A developer is deploying a new version of a Lambda function using the AWS CLI. The function is part of a serverless application that processes S3 events. The developer wants to ensure that the new version is production-ready and that the old version is still available for rollback. Which CLI command should the developer use to create a new version of the Lambda function?

Accepted Answer

aws lambda publish-version --function-name my-function. Option A is correct because the `aws lambda publish-version` command creates an immutable, versioned snapshot of the Lambda function's code and configuration, which is required for production-ready deployments. This ensures the old version remains available for rollback while the new version is published with a unique version number (e.g., $LATEST, 1, 2). The command explicitly publishes the current $LATEST version as a new numbered version, making it production-ready without affecting existing versions.

Answer

aws lambda update-function-configuration --function-name my-function --handler new-handler

Answer

aws lambda update-function-code --function-name my-function --zip-file fileb://my-code.zip

Answer

aws lambda create-function --function-name my-function --zip-file fileb://my-code.zip

Question 6

A developer is using AWS CodePipeline to deploy a web application. The pipeline has a source stage from Amazon S3, a build stage using AWS CodeBuild, and a deploy stage using AWS CodeDeploy. The developer notices that the deploy stage fails intermittently due to EC2 instances not being available. Which TWO actions should the developer take to improve the reliability of the deployment? (Choose two.)

Accepted Answer

Configure the CodeDeploy deployment group to have a minimum healthy hosts threshold.. Option B is correct because configuring a minimum healthy hosts threshold in the CodeDeploy deployment group ensures that a certain percentage or number of EC2 instances remain healthy during the deployment. This prevents the deployment from proceeding if too many instances are unavailable, reducing the risk of failure due to insufficient capacity. Option E is correct because adding a manual approval step before the deploy stage allows the developer to verify instance health (e.g., via AWS Systems Manager or custom scripts) before triggering the deployment, catching availability issues early.

Answer

Increase the number of EC2 instances in the Auto Scaling group to ensure availability.

Answer

Reduce the deployment timeout to fail faster.

Answer

Use a different deployment type, such as blue/green, instead of in-place.

Question 7

A developer is deploying a microservices architecture on Amazon ECS. The services need to communicate with each other securely. The developer wants to use service discovery and ensure that traffic between services is encrypted. Which combination of services should the developer use?

Accepted Answer

Use AWS Cloud Map for service discovery and AWS App Mesh with mutual TLS. Option D is correct because ECS service discovery with AWS Cloud Map provides DNS-based service discovery, and mTLS via App Mesh or service mesh provides encryption. Option A is incorrect because ELB is for external traffic. Option B is incorrect because API Gateway is for APIs. Option C is incorrect because Route 53 is not suitable for service discovery in ECS.

Answer

Use Amazon API Gateway and AWS Lambda

Answer

Use Amazon Route 53 private hosted zones and enable DNSSEC

Answer

Use an Application Load Balancer for each service and enable TLS termination

Question 8

A developer is troubleshooting a slow web application. The application uses an Application Load Balancer, EC2 instances, and an RDS database. The developer suspects the database is the bottleneck. Which TWO CloudWatch metrics should the developer examine to confirm this? (Select TWO.)

Accepted Answer

DatabaseConnections. Options B and D are correct. DatabaseConnections shows current connections; ReadIOPS and WriteIOPS show disk I/O, which can cause slowness. Option A (CPUUtilization) is a general metric, but for database bottleneck, I/O and connections are more indicative. Option C (NetworkIn) is more about network load. Option E (RequestCount) is for the ALB, not the database.

Answer

RequestCount

Answer

NetworkIn

Answer

CPUUtilization

Question 9

A web application running on EC2 instances behind an Application Load Balancer (ALB) is experiencing intermittent 503 errors. The ALB target group health checks are succeeding. Which step should the developer take FIRST to diagnose the issue?

Accepted Answer

Examine the ALB access logs for 503 responses.. Option D is correct because examining ALB access logs can reveal the response status codes and request details. Option A is wrong because health checks succeed. Option B is wrong because increasing instances may not address the root cause. Option C is wrong because the issue is with the ALB, not DNS.

Answer

Increase the number of EC2 instances in the target group.

Answer

Check the Route 53 record for the ALB.

Answer

Verify that the EC2 instances are in a running state.

Question 10

A company is deploying a microservices application on Amazon ECS using the Fargate launch type. The application includes a service that must process messages from an Amazon SQS queue. The developer wants to ensure that the service scales based on the number of messages in the queue. Which scaling solution should the developer implement?

Accepted Answer

Use Amazon ECS Service Auto Scaling with a target tracking scaling policy based on the SQS queue backlog per task.. Option C is correct because Amazon ECS Service Auto Scaling with a target tracking scaling policy based on the SQS queue backlog can automatically adjust the number of tasks. Option A is wrong because Application Auto Scaling with a scheduled scaling policy is not dynamic. Option B is wrong because DynamoDB auto scaling is for database throughput, not ECS tasks. Option D is wrong because Lambda reserved concurrency limits the number of concurrent executions but does not scale ECS tasks.

Answer

Configure DynamoDB auto scaling to adjust read capacity based on queue depth.

Answer

Configure AWS Lambda with reserved concurrency and trigger it from the SQS queue.

Answer

Use Application Auto Scaling with a scheduled scaling policy to increase the number of tasks during peak hours.