DVA-C02 Deployment Practice Test 14 — 15 Questions

Question 1

A developer is using AWS CodeBuild to build a Java application. The build succeeds locally but fails in CodeBuild with the error 'BUILD FAILED: Unable to find a Java installation.' The buildspec.yml file includes a 'runtime-versions' section specifying Java 11. The CodeBuild project uses the 'aws/codebuild/amazonlinux2-x86_64-standard:4.0' image. What is the MOST likely cause of the failure?

Accepted Answer

The runtime-versions section in buildspec.yml is not correctly formatted.. The error 'Unable to find a Java installation' indicates that the CodeBuild environment does not have Java available at runtime. When using a standard managed image like 'aws/codebuild/amazonlinux2-x86_64-standard:4.0', Java must be explicitly declared in the 'runtime-versions' section of buildspec.yml. The most likely cause is that the 'runtime-versions' section is incorrectly formatted (e.g., using 'java: 11' instead of the correct 'java: corretto11'), causing CodeBuild to skip installing Java.

Answer

The CodeBuild project does not have sufficient permissions to download Java.

Answer

The buildspec.yml file is not in the root of the source directory.

Answer

The build commands reference a non-existent Maven dependency.

Question 2

A company uses AWS Elastic Beanstalk to deploy a Python web application. After a recent deployment, the environment health turns 'Severe' and the application becomes unresponsive. The developer checks the logs and finds multiple '502 Bad Gateway' errors from the nginx proxy. The application was working before the deployment. What is the MOST likely cause?

Accepted Answer

The new application code has a bug that causes the application to crash.. A 502 Bad Gateway error from nginx means the reverse proxy cannot communicate with the application backend. Since the application was working before the deployment and became unresponsive immediately after, the most likely cause is a bug in the new code that causes the application process to crash or hang. Elastic Beanstalk's nginx proxy expects a healthy response from the application on the designated port; if the application fails to start or crashes repeatedly, nginx returns 502 errors.

Answer

The Procfile is missing from the application source.

Answer

The environment's load balancer is not configured correctly.

Answer

The environment variables are not set correctly.

Question 3

A developer deploys a new version of an AWS Lambda function using the AWS CLI. After the deployment, the function starts returning errors. The developer needs to quickly revert to the previous version without redeploying. What should the developer do?

Accepted Answer

Update the alias to point to the previous version.. Option B is correct because AWS Lambda aliases are immutable pointers to specific function versions. By updating the alias to point to the previous version, the developer can instantly revert traffic to the stable code without any redeployment, as the alias is used as the invocation target (e.g., via the function's ARN with the alias name). This approach leverages Lambda's built-in versioning and alias routing, which is the fastest and safest rollback mechanism.

Answer

Use AWS CodeDeploy to automatically roll back the deployment.

Answer

Use the AWS CLI to update the function code with the previous code.

Answer

Delete the current function and recreate it using the previous deployment package.

Question 4

A company uses AWS CodeDeploy to deploy a web application to an Auto Scaling group of Amazon EC2 instances. The deployment fails with the error 'The overall deployment failed because too many individual instances failed deployment, too few healthy instances are available for deployment, or some instances in your deployment group are experiencing problems.' The developer needs to identify the root cause. Which AWS service should the developer use to view detailed error logs from the failed deployment?

Accepted Answer

Amazon CloudWatch Logs (if configured) or the CodeDeploy agent log files on the EC2 instances. Option A is correct because when a CodeDeploy deployment fails due to instance-level errors, the most direct way to investigate is to examine the CodeDeploy agent logs located on each EC2 instance at `/opt/codedeploy-agent/deployment-root/deployment-logs/codedeploy-agent.log`. If Amazon CloudWatch Logs has been configured to stream these logs, you can also view them centrally in the CloudWatch console. These logs contain detailed error messages from the `codedeploy-agent` process, including script failures, permission issues, or missing dependencies that caused the deployment to fail.

Answer

AWS X-Ray

Answer

AWS CloudTrail

Answer

AWS CodeDeploy console

Question 5

A developer is using AWS CloudFormation to deploy a stack that includes an Amazon RDS DB instance. The developer wants to update the stack to change the DB instance class. The update fails because CloudFormation cannot modify the DB instance class without replacement. The developer needs to complete the update with minimal downtime. What should the developer do?

Accepted Answer

Use a custom resource with an AWS Lambda function to perform the modification, ensuring data is backed up and downtime is minimized.. Option B is correct because a custom resource backed by an AWS Lambda function allows you to perform the RDS DB instance class modification outside of CloudFormation's direct lifecycle, enabling you to use the 'ApplyImmediately' parameter to minimize downtime. CloudFormation's native update for RDS DB instance class requires replacement (i.e., a new physical resource), which causes downtime; a custom resource can orchestrate a 'modify-db-instance' API call with '--apply-immediately' to change the class in-place with only a brief reboot.

Answer

Delete the stack and create a new stack with the new DB instance class.

Answer

Update the stack and disable rollback on failure.

Answer

Update the stack using a change set, then execute it.

Question 6

A developer is deploying a serverless application using the AWS Serverless Application Model (SAM). The developer wants to ensure that the Lambda function's environment variables are encrypted at rest. What is the most straightforward way to achieve this?

Accepted Answer

No action needed; SAM automatically encrypts environment variables at rest using a default KMS key.. Option A is correct because SAM automatically enables encryption at rest for environment variables using AWS KMS. Option B is wrong because the encryption is done by default. Option C is wrong because manual KMS key creation is not required for default encryption. Option D is wrong because the serverless function handler does not affect encryption.

Answer

Enable encryption in the SAM template using the 'Encrypt' property.

Answer

Modify the Lambda function's code to encrypt environment variables before deployment.

Answer

Create a customer managed KMS key and specify it in the SAM template.

Question 7

A company uses AWS Elastic Beanstalk to deploy a web application. The developer has updated the application code and wants to deploy the new version with a rolling deployment strategy to minimize downtime. Which configuration should the developer use?

Accepted Answer

Set the deployment policy to 'Rolling'. Option B is correct because Rolling deployment updates instances in batches, minimizing downtime. Option A is wrong because All at once causes downtime. Option C is wrong because Immutable creates new instances and swaps, but Rolling is more cost-effective. Option D is wrong because Blue/green is a separate deployment method.

Answer

Set the deployment policy to 'Immutable'

Answer

Set the deployment policy to 'All at once'

Answer

Set the deployment policy to 'Blue/green'

Question 8

A developer is deploying a microservices application on Amazon ECS using Fargate. The developer wants to implement a blue/green deployment strategy using AWS CodeDeploy. The current production environment uses an Application Load Balancer (ALB). What is the minimum configuration required to enable blue/green deployments?

Accepted Answer

An ALB with two target groups, one for blue and one for green.. Option A is correct because CodeDeploy blue/green requires an ALB and a target group for each environment. Option B is wrong because NLB also works but requires additional configuration. Option C is wrong because CloudFront is not required. Option D is wrong because ECS service discovery is not necessary.

Answer

An ALB with a single target group and an Amazon CloudFront distribution.

Answer

An ECS service discovery namespace.

Answer

A Network Load Balancer (NLB) with a single target group.

Question 9

A developer uses AWS CodeCommit to store source code. The developer wants to automatically trigger a build in AWS CodeBuild every time a new commit is pushed to the master branch. Which AWS service should the developer use to configure this integration?

Accepted Answer

AWS CodePipeline. Option C is correct because CodePipeline can be configured to trigger on CodeCommit events and start a CodeBuild project. Option A is wrong because CloudWatch Events can trigger CodeBuild directly, but CodePipeline is the standard integration. Option B is wrong because CodeDeploy is for deployment, not build. Option D is wrong because S3 events are not directly related to CodeCommit.

Answer

Amazon CloudWatch Events (or EventBridge)

Answer

Amazon S3 events

Answer

AWS CodeDeploy

Question 10

A team is using AWS CodeBuild to compile and test code. The build takes longer than expected. The team wants to reduce build times by caching dependencies. Which option should the team use to cache dependencies in CodeBuild?

Accepted Answer

Local caching or Amazon S3 caching. Option B is correct because CodeBuild supports local caching and S3 caching; local caching stores dependencies on the build instance. Option A is wrong because EFS is not supported for caching in CodeBuild. Option C is wrong because ECR is for container images, not general dependency caching. Option D is wrong because DynamoDB is not used for caching in CodeBuild.

Answer

Amazon DynamoDB

Answer

Amazon EFS

Answer

Amazon ECR

Question 11

A company has a legacy application that runs on an Amazon EC2 instance. The developer is tasked with containerizing the application and deploying it on Amazon ECS with Fargate. The application writes logs to a local file. What should the developer do to ensure logs are available in Amazon CloudWatch Logs?

Accepted Answer

Configure the ECS task definition to use the 'awslogs' log driver and specify the log group.. Option A is correct because using the awslogs log driver sends container logs to CloudWatch Logs. Option B is wrong because CloudWatch Agent inside the container is less efficient. Option C is wrong because ECS does not send logs automatically. Option D is wrong because S3 is not a direct log destination.

Answer

Modify the application to write logs to stdout, as ECS automatically captures stdout to CloudWatch Logs.

Answer

Install the CloudWatch Agent inside the container and configure it to tail the log file.

Answer

Mount an Amazon S3 bucket and write logs to S3, then use a Lambda function to send them to CloudWatch.

Question 12

A developer is using AWS CloudFormation to manage infrastructure. The developer needs to update a stack that contains a resource that requires replacement. Which TWO actions can the developer take to perform the update with minimal downtime?

Accepted Answer

Create a new stack with the updated resource and then update the DNS to point to the new stack.. Options A and D are correct because creating a new stack in parallel and using a blue/green deployment with CodeDeploy minimize downtime. Option B causes downtime. Option C is not a method. Option E does not address downtime.

Answer

Use a change set and execute it, allowing CloudFormation to replace the resource.

Answer

Use the 'Stack Policy' to prevent replacement.

Answer

Delete the stack and recreate it.

Question 13

A company uses AWS CodePipeline to deploy a web application. The pipeline has a Source stage (CodeCommit), a Build stage (CodeBuild), and a Deploy stage (CodeDeploy). The developer wants to add a manual approval step before the Deploy stage. Which TWO configurations are required?

Accepted Answer

An IAM role that allows CodePipeline to publish to the SNS topic.. Options B and D are correct because a manual approval action requires an SNS topic for notification and an IAM role for the pipeline to publish to SNS. Option A is wrong because Lambda is not required. Option C is wrong because CloudWatch is not needed. Option E is wrong because SES is not used.

Answer

An Amazon SES identity to send emails.

Answer

An AWS Lambda function to send approval emails.

Answer

An Amazon CloudWatch alarm to trigger the approval.

Question 14

A developer is deploying a containerized application on Amazon ECS with Fargate. The application requires access to an Amazon RDS database. The developer needs to securely pass database credentials to the container. Which THREE methods can the developer use?

Accepted Answer

Store the credentials in AWS Systems Manager Parameter Store and reference the parameter in the task definition.. Options A, C, and D are correct. Option B is wrong because hardcoding credentials is insecure. Option E is wrong because environment variables in the task definition are visible in plain text.

Answer

Hardcode the credentials in the container image.

Answer

Define environment variables in the task definition with the credentials.

Question 15

A company deploys a critical application on Amazon ECS with Fargate using a blue/green deployment strategy with AWS CodeDeploy. The deployment group has two target groups, one for blue and one for green. The Application Load Balancer (ALB) is configured with a listener that forwards traffic to the blue target group initially. A recent deployment to the green environment failed, and the green service is in a steady state with zero healthy tasks. The developer needs to ensure that the blue service continues to serve traffic without interruption. The developer checks the CodeDeploy console and sees that the deployment is stuck in the 'InProgress' state with a status of 'Green fleet is not healthy.' What should the developer do to restore the deployment to a healthy state?

Accepted Answer

Stop the deployment in CodeDeploy and re-point the ALB listener to the blue target group.. Option B is correct because stopping the deployment and rerouting traffic to the blue target group ensures the blue service continues to serve traffic. Option A is wrong because manually updating the blue service does not address the stuck deployment. Option C is wrong because updating the green service may not fix the deployment. Option D is wrong because rolling back may not be available if the deployment is stuck.

Answer

Update the ECS task definition for the green service to a working version and wait for the deployment to complete.

Answer

Manually update the ECS service for the blue environment to increase the desired count.

Answer

Roll back the deployment to the previous version using the CodeDeploy console.