DVA-C02 Deployment Practice Test 7 — 15 Questions

Question 1

A company uses AWS CodePipeline with a source stage from Amazon S3. The pipeline triggers on changes to the S3 bucket. However, the pipeline does not trigger when a new object is uploaded. What is the MOST likely cause?

Choose an answer to begin — your selection is scored in the full session.

Answer

The S3 bucket policy denies access to CodePipeline.

Answer

The S3 bucket does not have an event notification configured for the pipeline.

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The pipeline is not configured with a webhook.

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The object is encrypted and CodePipeline cannot read it.

Question 2

A developer is creating a CloudFormation template to deploy a microservices architecture. The template includes an Amazon ECS service with an Application Load Balancer. The developer wants to ensure that the load balancer is created before the ECS service. How should the developer achieve this?

Accepted Answer

Use the DependsOn attribute in the ECS service resource to reference the load balancer.. The DependsOn attribute explicitly defines resource creation order in AWS CloudFormation. By setting DependsOn on the ECS service to reference the load balancer, the template ensures the load balancer is fully created before the ECS service attempts to register with it, preventing deployment failures due to missing dependencies.

Answer

Use the Ref function in the ECS service to reference the load balancer.

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Define the load balancer before the ECS service in the template.

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Use the Fn::GetAtt function to reference the load balancer.

Question 3

Which TWO are benefits of using AWS CloudFormation for infrastructure deployment? (Choose two.)

Accepted Answer

Infrastructure is provisioned consistently across environments.. AWS CloudFormation uses templates to define infrastructure as code, ensuring that the same set of resources is provisioned identically across multiple environments (e.g., dev, test, prod). This eliminates configuration drift and manual errors by applying the same template consistently, which is a core benefit of infrastructure as code.

Answer

Automatically enforces compliance rules.

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Replaces the need for a CI/CD pipeline.

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Provides real-time monitoring of deployed resources.

Question 4

A company is deploying a new microservice using AWS Lambda and Amazon API Gateway. Which THREE steps should be included in the deployment pipeline? (Choose three.)

Accepted Answer

Deploy the API Gateway API to a stage.. Deploying the API Gateway API to a stage is essential because it makes the API publicly available at a specific URL (e.g., https://api-id.execute-api.region.amazonaws.com/prod). Without a stage deployment, any updates to the API resources and methods remain in draft state and are not accessible to clients.

Answer

Invalidate the Amazon CloudFront cache.

Answer

Update the Route 53 DNS record to point to the new API.

Question 5

Which TWO are valid deployment strategies in AWS CodeDeploy? (Choose two.)

Accepted Answer

AllAtOnce. AWS CodeDeploy supports two deployment types: In-place and Blue/green. In-place deployments update the application on existing instances in the deployment group. Blue/green deployments replace the instances or task sets with new ones running the updated version. 'Rolling' and 'Immutable' are deployment strategies used by AWS Elastic Beanstalk, not CodeDeploy deployment types. 'Canary' is a deployment configuration (not a deployment type) used in CodeDeploy for Lambda and ECS.

Answer

Rolling

Answer

Immutable

Answer

Canary

Question 6

A company uses AWS CodePipeline to deploy a containerized application to Amazon ECS with Fargate. The pipeline consists of a source stage (Amazon ECR), a build stage (CodeBuild), and a deploy stage (CodeDeploy with ECS Blue/Green). Recently, after a successful build, the deploy stage fails with the error 'Service deployment failed because the task definition is not compatible with the target group.' The task definition uses the 'awsvpc' network mode and specifies a port mapping of 80. The target group is configured to use port 80. What is the MOST likely cause of the failure?

Accepted Answer

The task definition port mapping does not match the target group port.. The error 'Service deployment failed because the task definition is not compatible with the target group' occurs when there is a mismatch between the network mode of the task definition and the target type of the target group. Amazon ECS on Fargate requires the 'awsvpc' network mode. When using 'awsvpc' network mode, the associated Application Load Balancer target group must have its target type set to 'ip'. If the target group is configured with a target type of 'instance', the deployment will fail with this compatibility error.

Answer

The task definition does not include a logging configuration for CloudWatch Logs.

Answer

The task definition uses the 'awsvpc' network mode, which is not supported for Blue/Green deployments.

Answer

The target group health check path is not configured correctly.

Question 7

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.. AWS Lambda versions are immutable, while aliases are mutable 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 8

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?

Answer

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

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Use a custom resource with an AWS Lambda function to perform the modification, ensuring data is backed up and downtime is minimized.

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Update the stack and disable rollback on failure.

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

Question 9

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.. When an application in an ECS container writes logs to stdout or stderr, the 'awslogs' log driver can be configured in the ECS task definition to automatically stream these logs to Amazon CloudWatch Logs. This is the standard and most efficient way to handle container logging in ECS Fargate without needing sidecars or agents.

Answer

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

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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 10

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.. Creating a new stack with the updated resource and then updating DNS to point to the new stack allows for a seamless switch with minimal downtime. Option E is incorrect because AWS CodeDeploy is designed for application deployments, not for orchestrating CloudFormation stack updates or resource replacements. Using a change set (A) would cause downtime as the resource replacement happens in place. Stack policy (B) can prevent replacement but does not help perform the update. Deleting and recreating the stack (C) causes significant 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.

Answer

Use AWS CodeDeploy with a blue/green deployment to manage the replacement.

Question 11

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.. The deployment is stuck due to the green fleet being unhealthy. Stopping the deployment in CodeDeploy will terminate the stuck deployment and allow you to reconfigure the ALB listener to point to the blue target group, ensuring the blue service continues to serve traffic without interruption. Option A is incorrect because updating the task definition for the green service will not automatically resume or fix the stuck deployment; the deployment is already in a failed state. Option B is incorrect because manually increasing the desired count of the blue service does not address the root cause—the stuck deployment—and the listener may still be routing traffic to the green target group. Option D is incorrect because rolling back the deployment may not be possible while the deployment is in 'InProgress' state; you typically need to stop the deployment first before initiating a rollback.

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.

Question 12

A developer is using AWS CodeBuild to build a Java application. The buildspec.yml file includes commands to run unit tests and package the application. Recently, the build started failing with the error 'No space left on device.' The developer notices that the build environment is using the general1.large compute type with 8 GB of disk space. The developer needs to resolve the disk space issue without modifying the application code. The build environment is managed by CodeBuild and the developer cannot change the instance type. What should the developer do?

Accepted Answer

Add a command in the buildspec.yml to clean the cache directory before the build phase.. Cleaning the cache directory before the build phase frees up disk space, resolving the 'No space left on device' error. Option B is incorrect because using an EFS file system as a cache does not free up space on the build container; it only provides additional storage for dependencies, but CodeBuild does not natively support EFS as a cache. Option C is incorrect because changing the compute type to general1.medium does not change disk space; it still has 8 GB, and the developer cannot change the instance type anyway. Option D is incorrect because mounting an additional EBS volume is not supported in CodeBuild build environments; the developer cannot modify the underlying instance.

Answer

Use an Amazon EFS file system as a cache to store dependencies.

Answer

Change the compute type to general1.medium with 8 GB disk space.

Answer

Mount an additional Amazon EBS volume to the build container.

Question 13

A developer is using AWS CloudFormation to deploy a stack that includes an Amazon S3 bucket with a bucket policy that grants public read access. The stack creation fails with the error 'Access Denied for bucket: bucket-policy does not allow access.' The developer has full administrative permissions in AWS. The developer verifies that the bucket policy is correctly formatted. What is the most likely cause of the failure?

Accepted Answer

The S3 Block Public Access settings are enabled at the account level, preventing the bucket policy from granting public access.. AWS S3 Block Public Access settings (at the account or bucket level) prevent the creation of public bucket policies. When CloudFormation attempts to apply a public bucket policy while Block Public Access is enabled, S3 rejects the PutBucketPolicy API call with an 'Access Denied' error. Since the developer has full administrative permissions, the failure is not due to missing IAM permissions but rather S3 Block Public Access blocking the public policy.

Answer

The developer does not have permissions to create S3 buckets.

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The S3 bucket name is already in use by another account.

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The S3 bucket is encrypted with AWS KMS, and the bucket policy does not include kms:Decrypt permissions.

Question 14

A development team uses AWS Elastic Beanstalk to deploy a containerized application. They notice that after a successful deployment, the environment's health turns from Green to Red. The application logs show no errors. What is the most likely cause?

Accepted Answer

The ELB health check endpoint returns a 503 status code after the new version is deployed.. After a successful deployment, the environment turns Red if the ELB health check endpoint returns a non-200 status (e.g., 503) on the new version. Elastic Beanstalk uses ELB health checks to determine environment health; if the health check fails, the environment health changes to Red even if application logs show no errors. Option B is incorrect because a missing environment variable typically causes deployment failure or immediate instance health issues, not a post-deployment health change. Option C is incorrect because Docker image incompatibility with the platform version would cause deployment failure or instance launch failure, not a health change after successful deployment. Option D is incorrect because a low Auto Scaling minimum instance count does not directly affect health status after a successful deployment; it would affect scaling behavior.

Answer

The deployment failed due to a missing environment variable.

Answer

The application's Docker image is not compatible with the platform version.

Answer

The Auto Scaling group's minimum instance count is too low.

Question 15

A company uses AWS CodeBuild to compile and package code, and AWS CodePipeline to orchestrate deployments to Amazon ECS. The pipeline includes a manual approval step. During a recent deployment, the build succeeded but the pipeline failed at the deploy stage with the error 'CannotPullContainerError: manifest for image:tag not found'. The ECS task definition references the image:tag. What is the most likely cause?

Accepted Answer

The CodeBuild project does not have permissions to push to Amazon ECR.. When the ECS task execution role lacks the necessary permissions (such as `ecr:BatchGetImage` and `ecr:GetDownloadUrlForLayer`) to pull the image from Amazon ECR, ECR returns a 'not found' error to prevent exposing whether a private repository exists. This results in the ECS agent throwing the 'CannotPullContainerError: manifest for image:tag not found' error.

Answer

The ECS cluster does not have internet access to pull the image from ECR.

Answer

The image tag used is 'latest', and a subsequent build pushed a new 'latest' image, overwriting the original before the manual approval was granted.

Answer

The task definition references an incorrect image name.