DVA-C02 Deployment Practice Test 25 — 15 Questions

Question 1

A developer is using AWS CodeDeploy to deploy an application to an Amazon EC2 Auto Scaling group. The deployment fails because the CodeDeploy agent on the instances is not running. Which TWO steps should the developer take to resolve this issue? (Choose TWO.)

Accepted Answer

Install the CodeDeploy agent on the instances.. Options A and C are correct. A: Installing the agent ensures it's present. C: Starting the agent makes it operational. Option B is wrong because user data runs at launch, not on existing instances. Option D is wrong because restarting the instance may not start the agent if it's not installed. Option E is wrong because IAM roles are necessary but don't start the agent.

Answer

Attach an IAM role to the instances that allows CodeDeploy actions.

Answer

Reboot the instances.

Answer

Add a script in the Auto Scaling group's launch configuration user data to install the agent.

Question 2

A company uses AWS Elastic Beanstalk to deploy a web application. The application uses an Amazon RDS database. The developer wants to ensure that the database connection string is not hard-coded in the application code. Which THREE methods can the developer use to pass the connection string securely? (Choose THREE.)

Accepted Answer

Use AWS Secrets Manager.. Options A, B, and D are correct. A: Environment properties in Elastic Beanstalk are injected into the application. B: AWS Systems Manager Parameter Store provides secure, encrypted storage. D: AWS Secrets Manager is designed for secrets like database credentials. Option C is wrong because the application code should not read from RDS tags; tags are not intended for sensitive data. Option E is wrong because putting the connection string in a file in the deployment package is not secure.

Answer

Read the connection string from Amazon RDS tags.

Answer

Store the connection string in a configuration file in the application bundle.

Question 3

A company is deploying a microservices-based application on Amazon ECS using Fargate. The application consists of three services: frontend, backend, and database. The database service uses Amazon Aurora Serverless. The frontend and backend services are deployed as separate ECS services. The company uses AWS CodePipeline for CI/CD. Each service has its own CodePipeline pipeline that builds a Docker image and pushes it to Amazon ECR, then updates the ECS service with the new image. Recently, the backend service deployment started causing intermittent errors. After investigation, the developer found that the backend service is being updated while the frontend service is still pointing to the old backend version, causing API incompatibility. The developer needs to ensure that the backend service is updated before the frontend service, and that both are updated atomically. The developer also wants to automate the update process using CodePipeline. What should the developer do?

Accepted Answer

Create a single pipeline with separate stages: first deploy backend, then after successful deployment, deploy frontend.. Option D is correct because a single pipeline with sequential stages ensures the backend is deployed first, and the frontend deploys only after the backend is stable. Option A is wrong because triggers don't control order. Option B is wrong because manual approval is not atomic and can be error-prone. Option C is wrong because updating services is not atomic; they should be in one pipeline.

Answer

Add a manual approval step between the backend and frontend pipelines.

Answer

Create a single pipeline that deploys both services simultaneously by updating both ECS services in a single CodeDeploy deployment.

Answer

Configure the frontend pipeline to trigger after the backend pipeline completes using Amazon CloudWatch Events.

Question 4

A developer is deploying a static website to Amazon S3. The website uses client-side JavaScript to make API calls to an AWS Lambda function via Amazon API Gateway. The developer wants to enable cross-origin resource sharing (CORS) on the API Gateway to allow the S3 website to make requests. After enabling CORS on the API Gateway and redeploying the API, the browser still reports CORS errors. The developer checks the API Gateway configuration and sees that the OPTIONS method is not defined. The developer has already enabled CORS via the API Gateway console, which should have created the OPTIONS method. However, it did not appear. What should the developer do to resolve the issue?

Accepted Answer

Manually add an OPTIONS method to the API Gateway resource and configure the CORS headers in the integration response.. Option B is correct because enabling CORS via the console should automatically create an OPTIONS method; if it didn't, manually adding it is the next step. Option A is wrong because the S3 bucket policy is not the cause of CORS errors. Option C is wrong because the Lambda function does not handle OPTIONS requests; API Gateway does. Option D is wrong because the browser's CORS check is based on the server response, not the client code.

Answer

Update the JavaScript in the website to use a different HTTP method.

Answer

Update the S3 bucket policy to allow cross-origin requests from any origin.

Answer

Modify the Lambda function to return CORS headers in its response.

Question 5

A company is using AWS CloudFormation to deploy a stack that includes an Amazon EC2 instance with an attached Amazon EBS volume. The developer wants to ensure that the EBS volume is deleted when the EC2 instance is terminated. The developer has set the DeletionPolicy attribute on the EBS volume resource to Delete. However, after terminating the EC2 instance through the console, the EBS volume is still present. The stack still exists. What is the most likely reason the volume was not deleted?

Accepted Answer

The DeletionPolicy attribute only takes effect when the CloudFormation stack is deleted, not when an individual resource is terminated.. Option A is correct because DeletionPolicy only applies when the stack is deleted, not when an individual resource is terminated. Option B is wrong because the EC2 instance termination does not trigger stack update. Option C is wrong because the EBS volume is not a root device; root device is an instance store or EBS volume. Option D is wrong because the DeleteOnTermination attribute on the EC2 instance's BlockDeviceMapping controls whether the volume is deleted when the instance is terminated, not the DeletionPolicy on the volume resource.

Answer

The EBS volume has a DeleteOnTermination attribute set to false.

Answer

The EBS volume is the root device of the EC2 instance.

Answer

The EC2 instance was terminated manually, not through a stack update.

Question 6

A company deploys a serverless application using AWS SAM. The application includes an API Gateway REST API and multiple Lambda functions. The developer wants to deploy a new version of the API with a canary release strategy, sending 10% of traffic to the new version initially. Which SAM template configuration should the developer use?

Accepted Answer

Set Type: Canary in the DeploymentPreference of the Lambda function and add CanarySetting: { Percent: 10 } under DeploymentPreference.. Option A is correct because AWS SAM's `DeploymentPreference` with `Type: Canary` on the Lambda function enables canary traffic shifting for the API Gateway integration. The `CanarySetting` property with `Percent: 10` specifies that 10% of traffic is initially routed to the new Lambda version, while the remaining 90% goes to the previous version. This configuration leverages SAM's built-in CodeDeploy integration to manage the canary release automatically.

Answer

Set CanarySetting: { Percent: 10 } in the API Gateway resource's properties.

Answer

Set Type: Canary and TrafficShiftType: Canary in the DeploymentPreference of the Lambda function.

Answer

Set Type: Canary in the DeploymentPreference of the Lambda function and add a Percentage: 10 property.

Question 7

A team uses AWS CodePipeline to deploy a microservices application to Amazon ECS. The pipeline has a Source stage (GitHub), a Build stage (CodeBuild), and a Deploy stage (ECS). During a deployment, the pipeline fails at the Deploy stage with the error: 'Action execution failed: Deployment failed. The service my-service has reached the maximum number of tasks.' The service is configured with a desired count of 2 and a maximum percent of 200%. What is the most likely cause of this failure?

Accepted Answer

There are already 4 tasks running for the service, which is the maximum allowed by the deployment configuration.. Option C is correct because the error indicates the service has reached the maximum number of tasks. With a desired count of 2 and maximum percent of 200%, ECS allows up to 4 tasks during deployment (2 * 200% = 4). If there are already 4 tasks running (e.g., due to a previous deployment that did not complete), the new deployment cannot start additional tasks. Option A is incorrect because insufficient memory would cause a different error (task failure). Option B is incorrect because the maximum percent is already set to 200%, which allows for rolling updates. Option D is incorrect because the pipeline is not related to EC2 instance limits; it uses Fargate or EC2 launch type, but the error is about task count.

Answer

The task definition references a memory value that exceeds the available container instance memory.

Answer

The service's minimum healthy percent is set too high, preventing new tasks from starting.

Answer

The pipeline is trying to deploy to an ECS cluster that has reached its Amazon EC2 instance limit.

Question 8

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 9

A developer is deploying a web application using AWS Elastic Beanstalk. The application requires a custom platform that is not provided by Elastic Beanstalk. The developer has created a custom platform using the Packer tool and has stored the platform artifacts in an Amazon S3 bucket. Which TWO steps are necessary to use this custom platform in Elastic Beanstalk? (Choose TWO.)

Accepted Answer

Define a custom platform version in the Elastic Beanstalk environment's configuration using a platform definition file.. Options A and D are correct. First, the developer must create a platform version resource in the Elastic Beanstalk environment configuration (option A). Then, the developer must specify the platform ARN in the environment's configuration (option D). Option B is incorrect because the platform is defined by the platform version, not the environment name. Option C is incorrect because the Packer template is used to build the platform, but the platform version resource points to the artifacts in S3. Option E is incorrect because the custom platform does not require a Dockerfile; it uses a custom AMI or other artifacts.

Answer

Set the environment's platform to 'Custom' and provide the S3 URL of the platform artifacts.

Answer

Create a Dockerfile in the application source bundle to define the custom platform.

Answer

Upload the Packer template to the Elastic Beanstalk console.

Question 10

A company uses AWS CodeDeploy to manage deployments to an Amazon EC2 Auto Scaling group. The deployment group is configured with a blue/green deployment type. The developer notices that after a deployment, the old instances (blue environment) are terminated immediately after the new instances (green environment) pass health checks. The company wants to keep the old instances running for 30 minutes to allow for quick rollback if issues are detected. Which TWO configuration changes should the developer make to achieve this? (Choose TWO.)

Accepted Answer

Set the 'terminateBlueInstancesOnDeploymentSuccess' action to 'KEEP_ALIVE'.. Options A and E are correct. To retain the old instances for a period, the developer must set the 'terminateBlueInstancesOnDeploymentSuccess' action to 'KEEP_ALIVE' (option A) and specify a 'terminationWaitTimeInMinutes' value of 30 (option E). Option B is incorrect because 'originalSettings' is not a valid retention type. Option C is incorrect because 'blueInstanceTermination' setting is not a property; the correct property is 'terminateBlueInstancesOnDeploymentSuccess'. Option D is incorrect because 'waitTimeForBlueTermination' is not a valid property name.

Answer

Set the 'blueInstanceTermination' property to 'WAIT'.

Answer

Set the 'blueInstanceTermination' property to 'originalSettings'.

Answer

Set the 'waitTimeForBlueTermination' to 30.

Question 11

A developer is deploying a serverless application using the AWS Serverless Application Model (SAM). The application includes an Amazon DynamoDB table and a Lambda function that reads from the table. The developer wants to define the DynamoDB table and the Lambda function in the SAM template. Which THREE resource types should the developer include in the template? (Choose THREE.)

Accepted Answer

AWS::DynamoDB::Table. Options A, B, and D are correct. In a SAM template, 'AWS::Serverless::Function' (option A) defines a Lambda function, 'AWS::Serverless::SimpleTable' (option B) defines a DynamoDB table, and 'AWS::DynamoDB::Table' (option D) can also be used for more advanced configurations. Option C, 'AWS::Serverless::DynamoDB', is not a valid SAM resource type (the correct one is 'AWS::Serverless::SimpleTable' or 'AWS::DynamoDB::Table'). Option E, 'AWS::Lambda::Function', is a CloudFormation resource, but SAM templates typically use 'AWS::Serverless::Function' for simplicity, though both are valid. However, since the question asks for SAM template, the recommended approach is to use serverless types.

Answer

AWS::Lambda::Function

Answer

AWS::Serverless::DynamoDB

Question 12

A company is using AWS CodeCommit as a source repository for a CI/CD pipeline. The developer has set up AWS CodePipeline with a source stage that uses CodeCommit. The pipeline triggers automatically on changes to the repository. The developer wants to ensure that only changes to the 'main' branch trigger the pipeline. Which THREE configurations should the developer set in the CodePipeline source stage? (Choose THREE.)

Accepted Answer

Disable 'Poll for source changes'.. Option B is correct because disabling 'Poll for source changes' is necessary when using event-based change detection (CloudWatch Events) to trigger the pipeline. When you set 'Change detection' to 'Amazon CloudWatch Events' (option C), you must disable polling to avoid duplicate triggers and ensure the pipeline only responds to CloudWatch Events triggered by commits to the specified branch. This configuration ensures that only changes to the 'main' branch (set in option E) initiate the pipeline.

Answer

Set 'Output artifact format' to 'CodeCommit'.

Answer

Set 'Repository name' to 'main'.

Question 13

A company is deploying a containerized application on Amazon ECS using Fargate launch type. The application consists of multiple microservices, each deployed as a separate ECS service. The company uses AWS CodePipeline to automate deployments. The pipeline has a Source stage (CodeCommit), a Build stage (CodeBuild), and a Deploy stage (ECS). Recently, a deployment failed because the new task definition referenced an environment variable that was not available in the Parameter Store. The developer wants to prevent such failures in the future by validating the task definition before deployment. The developer has access to the AWS CLI and the AWS SDKs. The pipeline is configured to use CodeBuild for the build stage. What is the MOST efficient way to validate the task definition before deployment?

Accepted Answer

Add a step in the CodeBuild buildspec that runs 'aws ecs register-task-definition --cli-input-json file://taskdef.json --no-cli-pager --dry-run' to validate the task definition.. Option B is correct because using the 'aws ecs register-task-definition --cli-input-json' command with the '--no-cli-pager' and '--dry-run' flags will validate the task definition without actually registering it. This command checks for syntax errors and missing references, including Parameter Store parameters. Option A is incorrect because the 'aws ecs describe-task-definition' command only retrieves existing task definitions, not validates new ones. Option C is incorrect because the 'aws ecs run-task' command will actually try to run the task, which could incur costs and may fail at runtime. Option D is incorrect because the 'aws ecs update-service' command updates a service, not validates a task definition.

Answer

Add a step in the CodeBuild buildspec that runs 'aws ecs update-service --service my-service --task-definition <task-def-arn>' to see if the service accepts the task definition.

Answer

Add a step in the CodeBuild buildspec that runs 'aws ecs run-task --task-definition <task-def-arn> --count 1' to test the task definition.

Answer

Add a step in the CodeBuild buildspec that runs 'aws ecs describe-task-definition --task-definition <task-def-arn>' to check if the task definition exists.

Question 14

A developer is deploying a web application on AWS Elastic Beanstalk. The application uses a relational database and requires a custom environment variable for the database connection string. The developer has created an Elastic Beanstalk environment and wants to set the environment variable securely without exposing it in the source code or configuration files. The developer also wants to ensure that the environment variable is available to the application instances at deployment time. What is the BEST way to achieve this?

Accepted Answer

Set the environment variable using the Elastic Beanstalk console or CLI by configuring environment properties.. Option B is correct because Elastic Beanstalk allows setting environment properties in the environment configuration, which are securely passed to the instances. Option A is incorrect because storing the connection string in a plain text file is insecure. Option C is incorrect because hardcoding the value in the application code is not secure and not a best practice. Option D is incorrect because although AWS Systems Manager Parameter Store can store the value, the application would need to retrieve it at runtime, adding complexity; Elastic Beanstalk environment properties are simpler and automatically injected.

Answer

Store the connection string in AWS Systems Manager Parameter Store and retrieve it from the application code at runtime.

Answer

Hardcode the connection string in the application code and commit it to the source repository.

Answer

Store the connection string in a file named 'env.txt' in the application source bundle and read it at application startup.

Question 15

A developer is using AWS CodeBuild to build and test a Java application. The buildspec.yaml file includes phases for install, pre_build, build, and post_build. The developer notices that the build fails intermittently due to network timeouts when downloading dependencies from an external repository. The developer wants to improve the reliability of the build by caching the dependencies. The build environment is Linux and the dependencies are stored in the /root/.m2 directory (Maven cache). The developer has an S3 bucket for caching. What should the developer add to the buildspec.yaml to enable caching?

Accepted Answer

Add a 'cache' section with 'paths' including '/root/.m2' and 'location' set to the S3 bucket ARN.. Option A is correct because adding a 'cache' section with 'paths' pointing to /root/.m2 and 'location' pointing to the S3 bucket will cache the Maven dependencies. Option B is incorrect because the 'artifacts' section is for output artifacts, not caching. Option C is incorrect because the 'env' section is for environment variables. Option D is incorrect because the 'phases' section defines build commands, not caching.

Answer

Add a 'phases' section with install commands to manually copy dependencies to S3.

Answer

Add an 'artifacts' section with 'files' including '/root/.m2/**/*' and 'location' set to the S3 bucket.

Answer

Add an 'env' section with 'parameter-store' variables to store the dependency paths.