DVA-C02 Practice Test 10 — 10 Questions

Question 1

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 2

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

Question 3

Which TWO approaches can a developer use to automate the deployment of a microservices application to Amazon ECS with Fargate, ensuring that each microservice is independently deployable and can scale based on demand?

Accepted Answer

Define each microservice as a separate ECS service with its own task definition. Using separate ECS services (A) and a CI/CD pipeline per microservice (B) ensures independent deployment and scaling. Option C (monolithic pipeline) defeats independence. Option D (single task definition) couples services. Option E (single service) does not allow independent scaling.

Answer

Define all microservices in a single task definition and run them as one service

Answer

Use a single ECS service with multiple containers per task definition

Answer

Use a single CodePipeline that builds all microservices together

Question 4

A developer is deploying a new version of a Lambda function using the AWS CLI. The developer wants to shift 10% of traffic to the new version and then gradually increase to 100% over 10 minutes. Which CLI command should the developer use?

Accepted Answer

aws lambda update-alias --function-name my-function --name prod --function-version 2 --routing-config AdditionalVersionWeights={"1":0.9}. The update-function-code command deploys a new version. To shift traffic, the developer must use the update-alias command with a routing configuration. Option C is correct because it creates an alias with a routing config. Option A (create-function) creates a new function. Option B (invoke) invokes a function. Option D (publish-version) publishes a version but does not shift traffic.

Answer

aws lambda publish-version --function-name my-function

Answer

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

Answer

aws lambda invoke --function-name my-function --payload '{}'

Question 5

A developer needs to deploy a containerized application on AWS. The application requires persistent storage that can be shared across multiple containers running on different EC2 instances. Which AWS service should the developer use?

Accepted Answer

Amazon Elastic File System (EFS). Amazon EFS provides NFS-based file storage that can be mounted to multiple EC2 instances and ECS tasks. Option A is correct. Option B (EBS) is block storage attached to a single instance. Option C (S3) is object storage, not a filesystem. Option D (RDS) is a relational database.

Answer

Amazon S3

Answer

Amazon Elastic Block Store (EBS)

Answer

Amazon RDS

Question 6

A developer is deploying a serverless application using AWS SAM. The application includes an API Gateway endpoint and a Lambda function. The developer wants to ensure that the Lambda function can be invoked only by the API Gateway and not directly. Which configuration should be used?

Accepted Answer

Add a resource-based policy with 'aws:SourceArn' condition set to the API Gateway ARN.. Option B is correct because the resource-based policy statement with 'aws:SourceArn' condition restricts invocation to the specific API Gateway ARN. Option A is wrong because 'aws:SourceAccount' alone does not restrict to API Gateway. Option C is wrong because VPC endpoint policies control access to the VPC endpoint, not Lambda invocation. Option D is wrong because Lambda resource policies cannot use 'aws:SourceVpce'.

Answer

Configure a VPC endpoint policy that allows only API Gateway.

Answer

Add a resource-based policy with 'aws:SourceAccount' condition.

Answer

Add a resource-based policy with 'aws:SourceVpce' condition set to the API Gateway VPC endpoint ID.

Question 7

A developer is using AWS CodeBuild to compile a Java application. The build project is configured with a 'buildspec.yml' file. The developer notices that the build succeeds on the local machine but fails in CodeBuild with the error: 'Error: Could not find or load main class com.example.App'. What is the most likely cause?

Accepted Answer

The buildspec.yml file does not include an 'install' phase to download dependencies.. Option B is correct because CodeBuild uses a clean environment; if the buildspec does not include the 'install' phase to download dependencies, the application will fail. Option A is wrong because Java is pre-installed in CodeBuild images. Option C is wrong because the error indicates a missing class, not a compile error. Option D is wrong because the 'artifacts' section only affects output, not execution.

Answer

The 'build' phase command is incorrect, causing compilation to fail.

Answer

The build environment does not have Java installed.

Answer

The 'artifacts' section in buildspec.yml is misconfigured.

Question 8

A developer is deploying a serverless application using the AWS Serverless Application Model (SAM). The developer wants to set environment variables for the Lambda function that are specific to the deployment stage (e.g., dev, prod). How should the developer accomplish this?

Accepted Answer

Use SAM parameters to pass stage-specific values into the template.. Option C is correct because SAM supports defining parameters with default values and then using them in the template. The developer can use the 'Parameters' section and pass different values for each stage. Option A is wrong because environment variables are not automatically injected by stage. Option B is wrong because hardcoding is not flexible. Option D is wrong because 'Conditions' are for resource creation, not variable values.

Answer

Define the environment variables in the Lambda function configuration and use 'Ref' with the stage name.

Answer

Hardcode the environment variables in the SAM template for each stage.

Answer

Use AWS CloudFormation 'Conditions' to set environment variables based on the stage.

Question 9

Refer to the exhibit. A developer has attached the above IAM policy to an IAM role used by an AWS Lambda function. The Lambda function reads and writes objects to an S3 bucket. However, the function fails when trying to write objects. What is the MOST likely cause?

Accepted Answer

The S3 bucket uses AWS KMS encryption, and the policy does not include KMS permissions.. Option B is correct because the bucket is encrypted with AWS KMS, and the policy does not include kms:Decrypt and kms:GenerateDataKey permissions. Option A is wrong because GetObject works. Option C is wrong because the bucket policy is not shown. Option D is wrong because the function role has the policy.

Answer

The S3 bucket policy denies the Lambda function.

Answer

The Lambda function does not have permission to read objects.

Answer

The Lambda function is not using the correct IAM role.

Question 10

A CloudFormation template defines a Lambda function and a version resource. After updating the function code in the S3 bucket, the developer updates the stack. The Lambda function is updated, but the version resource remains unchanged. What is the most likely reason?

Accepted Answer

The function code changed, but CloudFormation does not detect the change because the S3 key is the same.. Option A is correct. The Lambda version resource depends on the function's code. If the function's properties (except the code) do not change, CloudFormation does not update the function resource, and thus the version is not updated. Option B is incorrect; the version resource does not use DependsOn, but its FunctionName reference triggers an update if the function is updated. Option C is incorrect; the version is created after the function update. Option D is incorrect; the template does not use AutoPublishAlias.

Answer

The template should use AutoPublishAlias to create versions.

Answer

The version resource is created before the function update completes.

Answer

The version resource has a DependsOn clause that prevents it from updating.