DVA-C02 Deployment Practice Test 18 — 15 Questions

Question 1

A company uses AWS Elastic Beanstalk to deploy a Python web application. After a successful deployment, the environment's health turns 'Severe' and the application returns HTTP 502 errors. What is the most likely cause?

Accepted Answer

The application's requirements.txt file is missing a required dependency.. Option A is correct because if the application's dependencies (e.g., Python packages) are not included or installed, the application fails to start, causing a 502 error. Option B is incorrect because an incorrectly configured load balancer would cause 503 or 504 errors. Option C is incorrect because exceeding instance storage would cause disk full errors, not 502. Option D is incorrect because RDS connection string misconfiguration would cause application errors but not necessarily 502; the web server would still respond.

Answer

The EC2 instances have insufficient storage for the deployment.

Answer

The load balancer's health check path is incorrectly configured.

Answer

The RDS database connection string is incorrect.

Question 2

A company is deploying a critical application using AWS CloudFormation. The stack creation fails with a 'ROLLBACK_COMPLETE' status. The engineer wants to troubleshoot the failure without deleting the stack. What should the engineer do?

Accepted Answer

Use the 'aws cloudformation describe-stack-events' command to view the error messages.. Option D is correct because CloudFormation retains the stack after a rollback, and the engineer can view the events in the AWS Management Console or CLI to see the specific error messages. Options A and B are incorrect because stack deletion is not required. Option C is incorrect because rollback triggers are for rollback, not troubleshooting.

Answer

Use the 'aws cloudformation create-change-set' command with a rollback trigger.

Answer

Recreate the stack using the '--on-failure DO_NOTHING' option.

Answer

Delete the stack and recreate it with the '--disable-rollback' flag.

Question 3

A developer is using AWS CodeBuild to compile and test code. The build phase fails with the error: 'BUILD_FAILED: Error: No such file or directory.' What is the most likely cause?

Accepted Answer

The buildspec.yml file references a file or directory that does not exist in the source code.. Option C is correct because the error indicates that a file referenced in the buildspec.yml does not exist, often due to an incorrect path. Options A and B are incorrect: missing environment variables cause different errors, and insufficient permissions cause access denied errors. Option D is incorrect because network timeout errors are not related to file not found.

Answer

The build environment has a network timeout when accessing external dependencies.

Answer

The IAM role for CodeBuild does not have permissions to access the source repository.

Answer

The build environment does not have the required environment variables set.

Question 4

A company uses AWS OpsWorks to manage a stack of EC2 instances. After a deployment, the application becomes unresponsive. The engineer suspects that a configuration file was not updated correctly. What is the best way to verify the deployed configuration?

Accepted Answer

SSH into an instance and inspect the configuration files in /var/lib/aws/opsworks.. Option B is correct because OpsWorks stores the last applied configuration in /var/lib/aws/opsworks, and checking this location shows the actual configuration used. Option A is incorrect because JSON syntax errors cause deployment failures, not silent misconfiguration. Option C is incorrect because AWS Systems Manager Run Command is not specific to OpsWorks. Option D is incorrect because CloudWatch Logs may not contain configuration details.

Answer

Use AWS Systems Manager Run Command to execute a script that outputs the configuration.

Answer

Check the OpsWorks stack's logs for any JSON syntax errors in the custom JSON.

Answer

Review the application logs in Amazon CloudWatch Logs for configuration errors.

Question 5

A team is using AWS CodePipeline with multiple stages: Source, Build, Test, and Deploy. The Deploy stage uses AWS CodeDeploy to deploy to an EC2 Auto Scaling group. The pipeline runs successfully, but the application still serves the old version. What is the most likely cause?

Accepted Answer

The CodeDeploy deployment group is associated with a different Auto Scaling group than the one serving traffic.. Option A is correct because if the CodeDeploy deployment group is configured to deploy to a different Auto Scaling group, the new revision is deployed to the wrong instances. Option B is incorrect because the pipeline succeeded, so the artifact is not corrupted. Option C is incorrect because a misconfigured load balancer would cause health check issues but not serve the old version. Option D is incorrect because a failed CodeBuild stage would prevent the pipeline from reaching Deploy.

Answer

The load balancer's target group is not pointing to the correct instances.

Answer

The build artifact in the Source stage is corrupted.

Answer

The CodeBuild stage failed silently and did not produce a new artifact.

Question 6

A developer is deploying an application using AWS CloudFormation. The stack includes an Amazon RDS DB instance. To ensure secure credential management, which TWO actions should the developer take? (Choose TWO.)

Accepted Answer

Use AWS Systems Manager Parameter Store with a SecureString parameter for the password.. Options B and D are correct. Using AWS Secrets Manager or Systems Manager Parameter Store to store database credentials securely is a best practice. Option A is incorrect because hardcoding credentials in the template is insecure. Option C is incorrect because the default password is not automatically randomized; it must be explicitly set. Option E is incorrect because IAM database authentication is separate from credential storage.

Answer

Hardcode the master password in the CloudFormation template.

Answer

Use IAM database authentication to manage credentials.

Answer

Leave the master password empty so that CloudFormation generates a random password.

Question 7

A company is implementing a CI/CD pipeline for a containerized application using Amazon ECS and AWS CodePipeline. The team wants to ensure zero-downtime deployments. Which THREE strategies should the team implement? (Choose THREE.)

Accepted Answer

Use a blue/green deployment strategy with an Application Load Balancer.. Options A, B, and D are correct. Using a blue/green deployment with a load balancer, configuring health checks, and using ECS service auto scaling ensure zero-downtime. Option C is incorrect because stopping all tasks causes downtime. Option E is incorrect because a rolling update with a fixed batch size can cause downtime if not managed carefully, but it is not the best practice; the question asks for three correct strategies.

Answer

Use a rolling update with a fixed batch size of 100% of tasks.

Answer

Stop all existing tasks before starting new tasks.

Question 8

A developer is using AWS SAM to deploy a serverless application. The developer wants to enable canary deployments for the Lambda function. Which TWO resources must be configured in the SAM template? (Choose TWO.)

Accepted Answer

DeploymentPreference property on the AWS::Serverless::Function resource.. Options A and B are correct. The AutoPublishAlias property enables canary deployments by creating a new version and updating the alias. The DeploymentPreference property specifies the canary configuration. Option C is incorrect because the alias can be used for canary, but the deployment preference is required. Option D is incorrect because the function's code URI is always needed but not specific to canary. Option E is incorrect because the event source mapping is not related to canary deployment.

Answer

The function's CodeUri property pointing to the deployment package.

Answer

An event source mapping for the function.

Answer

The function's alias resource with a routing configuration.

Question 9

A developer needs to deploy a new version of a Lambda function that uses environment variables for database credentials. Which AWS service should be used to securely store and retrieve the credentials?

Accepted Answer

AWS Secrets Manager. AWS Secrets Manager is designed to securely store secrets such as database credentials and can automatically rotate them. Option B is correct because it provides encryption and access control. Option A (SSM Parameter Store) can store secrets but lacks automatic rotation. Option C (S3) is not secure for secrets. Option D (DynamoDB) is not intended for secret storage.

Answer

Amazon DynamoDB with encryption at rest

Answer

Amazon S3 with server-side encryption

Answer

AWS Systems Manager Parameter Store

Question 10

A company uses CodePipeline to deploy a web application to Elastic Beanstalk. The deployment fails at the Build stage with an error 'BUILD FAILED'. Which step should the developer take first to troubleshoot?

Accepted Answer

Review the buildspec.yml file for syntax errors. The error 'BUILD FAILED' indicates an issue during the build phase. The buildspec.yml file defines the build commands. Checking it is the first logical step. Option A is correct because the buildspec.yml is the configuration for CodeBuild. Option B (CloudTrail) is for API auditing, not build errors. Option C (CodeDeploy) is for deployment, not build. Option D (Elastic Beanstalk logs) are for runtime, not build.

Answer

Verify the CodeDeploy application revision

Answer

Examine the Elastic Beanstalk environment logs

Answer

Check AWS CloudTrail for API calls

Question 11

Which TWO actions should a developer take to minimize downtime when deploying a new version of a production application running on Amazon ECS with Fargate?

Accepted Answer

Configure the ECS service to use a blue/green deployment with CodeDeploy. Using a blue/green deployment (A) and updating the ECS service with a new task definition while setting the minimum healthy percent to 100% and maximum percent to 200% (B) both reduce downtime. Option C (delete and recreate) causes downtime. Option D (update target group) is part of blue/green but not a complete action. Option E (stop all tasks) causes downtime.

Answer

Delete the existing service and recreate it with the new task definition

Answer

Update the target group health check settings to a more lenient threshold

Answer

Stop all running tasks and then start new tasks with the updated image

Question 12

A developer uses CodePipeline to deploy a new task definition to an ECS service. The pipeline fails with an access denied error when updating the service. Which missing permission is the most likely cause?

Accepted Answer

Missing iam:PassRole permission for the task execution role used by the new task definition. The error occurs when updating the ECS service with a new task definition. The ecs:UpdateService action requires the iam:PassRole permission for the task execution role that the new task definition uses. The policy only allows iam:PassRole for a specific role, but the new task definition might reference a different role. Option B is correct because the policy does not allow passing the specific role referenced in the new task definition. Option A is incorrect because ecs:UpdateService is allowed. Option C is incorrect because there is no condition. Option D is incorrect because describe is allowed.

Answer

Missing ecs:UpdateService permission for the service resource

Answer

Missing ecs:DescribeServices permission

Answer

Missing ecs:RegisterTaskDefinition permission for the new task definition

Question 13

A developer is deploying a serverless application using AWS SAM. The application includes an API Gateway endpoint backed by a Lambda function. The developer wants to enable canary deployments to shift 10% of traffic to the new version for 5 minutes before routing all traffic. Which configuration should the developer add to the SAM template?

Accepted Answer

DeploymentPreference with Type: Canary10Percent5Minutes. SAM supports canary deployments using the DeploymentPreference property with a canary type. Option A is correct because it specifies a 10% canary for 5 minutes. Option B is linear, not canary. Option C is all-at-once. Option D is a custom traffic shifting method.

Answer

Add a CodeDeploy application and deployment group manually

Answer

DeploymentPreference with Type: Linear10PercentEvery1Minute

Answer

DeploymentPreference with Type: AllAtOnce

Question 14

A company uses AWS CodeCommit for source control. A developer needs to automate the build and test process for every commit to the 'develop' branch. The developer creates a CodeBuild project and wants to trigger it automatically. What is the most efficient way to set up this automation?

Accepted Answer

Create a CodePipeline with a source stage from CodeCommit and a build stage from CodeBuild. CodePipeline can be configured to start on changes to a CodeCommit repository and then invoke CodeBuild. Option C is correct because it uses a pipeline with a source trigger. Option A (CloudWatch Events) is less efficient as it requires a separate rule. Option B (webhooks) is used for third-party repositories. Option D (SQS) is unnecessary overhead.

Answer

Create a CloudWatch Events rule that triggers CodeBuild on code commit events

Answer

Configure a webhook in CodeCommit to call CodeBuild directly

Answer

Use an SQS queue to receive SNS notifications from CodeCommit and trigger CodeBuild

Question 15

Which THREE factors should a developer consider when choosing between a blue/green deployment and a rolling deployment for an Amazon ECS service?

Accepted Answer

Rolling deployments update a subset of tasks at a time, which may cause slower rollback. Blue/green deployments require additional resources (A), support quick rollback (B), and have higher cost (C). Option D (cost) is relevant. Option E (database schema changes) is not directly related; both can handle it with proper migration.

Answer

Rolling deployments require manual intervention to rollback

Answer

Blue/green deployments are always cheaper than rolling deployments