DVA-C02 Deployment Practice Test 22 — 15 Questions

Question 1

A developer performed a CodeDeploy deployment to an Auto Scaling group. The deployment status is Failed with code HEALTH_CONSTRAINTS. Based on the exhibit, what is the most likely cause?

Accepted Answer

The minimum number of healthy instances required for the deployment was not met. The HEALTH_CONSTRAINTS error in CodeDeploy means the deployment could not maintain the minimum number of healthy instances specified in the deployment configuration during the deployment. This typically occurs when instances fail health checks, the ASG cannot launch replacements fast enough, or the deployment configuration's minimum healthy hosts threshold is too high relative to available capacity. The most likely cause is that the minimum healthy instance requirement was not met.

Answer

The CodeDeploy agent on the instances is not running

Answer

The application revision contains invalid scripts

Answer

The IAM role for CodeDeploy does not have sufficient permissions

Question 2

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.. Adding a resource-based policy with an `aws:SourceArn` condition set to the API Gateway ARN ensures that the Lambda function can only be invoked by that specific API Gateway. This uses the AWS Identity and Access Management (IAM) condition key to restrict the `lambda:InvokeFunction` action based on the ARN of the invoking resource, preventing direct invocation from other sources like the AWS CLI or SDK.

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 3

A company is using AWS CodeDeploy to deploy a web application to an Auto Scaling group. The deployment fails with the error: 'The overall deployment failed because too many individual instances failed deployment, too few healthy instances are available, or some instances in your deployment group are experiencing problems.' The application is deployed to a t2.micro instance with 1 GB of RAM. The deployment uses an in-place update with a deployment configuration that has a minimum of 1 healthy host. What is the most likely cause of the failure?

Accepted Answer

The application uses too much memory, causing the instance to become unhealthy during deployment.. The most likely cause is option A: the application uses too much memory, causing the instance to become unhealthy during deployment. The t2.micro instance has only 1 GB of RAM. If the web application consumes significant memory, deploying a new version can trigger out-of-memory (OOM) errors, leading the instance to fail health checks. The deployment configuration requires a minimum of 1 healthy host, so when the instance becomes unhealthy, the deployment fails with the error about too few healthy instances. Option B (insufficient disk space) is unlikely because t2.micro instances typically have at least 8 GB of EBS storage, which is usually sufficient for downloading application revisions. Option C (CodeDeploy agent timeout) would produce a different error, such as 'deployment timed out,' not a message about healthy instances. Option D (insufficient IAM permissions) would result in authorization failures, such as 'AccessDenied' errors, not a health-related failure. Therefore, memory exhaustion due to the small instance size is the best explanation.

Answer

The instance does not have enough disk space to download the application revision.

Answer

The CodeDeploy agent timed out because the deployment took longer than 30 minutes.

Answer

The IAM role for the CodeDeploy agent does not have sufficient permissions to deploy the application.

Question 4

A company uses AWS Elastic Beanstalk to deploy a web application. The development team wants to deploy a new version of the application to a separate environment for testing before switching production traffic. Which deployment strategy should be used?

Accepted Answer

Blue/green deployment.. Blue/green deployment (Option C) creates a separate, independent environment (green) for the new version, allowing thorough testing before swapping the environment's URLs to route production traffic to the green environment. This minimizes risk and enables quick rollback. Option A (immutable) launches a new Auto Scaling group in the same environment but does not isolate the new version in a separate environment; Option B (all at once) updates all instances simultaneously in the same environment, causing downtime; Option D (rolling) updates instances in batches in the same environment, exposing some users to the new version during deployment.

Answer

Immutable deployment.

Answer

All at once deployment.

Answer

Rolling deployment.

Question 5

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.. AWS SAM natively supports template parameters, which allow you to pass stage-specific values (e.g., environment variables) at deployment time. By defining a parameter in the SAM template and referencing it in the Lambda function's `Environment.Variables` section, you can inject different values for dev, prod, etc., without modifying the template itself. This approach leverages CloudFormation's parameter substitution to keep the template reusable and environment-agnostic.

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 6

A company uses AWS CodePipeline to automate deployments. The pipeline source stage uses Amazon S3. The developer wants to automatically trigger the pipeline when a new version of the source file is uploaded. The developer has configured S3 event notifications to invoke a Lambda function that starts the pipeline. However, the pipeline is not triggering. What is the most likely cause?

Accepted Answer

The Lambda function does not have permission to start the pipeline.. The most likely cause is that the Lambda function does not have permission to start the pipeline. S3 event notifications can invoke Lambda regardless of whether S3 versioning is enabled, so versioning is not required. For the pipeline to start, the Lambda function's execution role must have permission to call codepipeline:StartPipelineExecution on the target pipeline. If that permission is missing, the S3 event will invoke Lambda but the pipeline will not start. (Note: the S3 bucket must also allow S3 to invoke the Lambda function; however, among the provided options, the missing Lambda permission to start the pipeline is the most likely cause.)

Answer

S3 versioning is not enabled on the bucket.

Answer

The pipeline execution role does not have permission to read from the S3 bucket.

Answer

The S3 bucket does not have a bucket policy that allows S3 to invoke Lambda.

Question 7

A company is implementing a CI/CD pipeline using AWS CodeCommit, CodeBuild, and CodeDeploy. The developer wants to ensure that the pipeline automatically deploys to production only after a manual approval step. Which TWO actions should the developer take?

Accepted Answer

Add a manual approval action in the CodePipeline pipeline.. Option B is correct because AWS CodePipeline natively supports a manual approval action that pauses the pipeline at a chosen stage until an approver acts, which is exactly the mechanism needed to gate production deployments. Option C is correct because the manual approval action can be configured with an IAM principal (user, role, or group) whose members are authorized to approve or reject, enforcing controlled authorization for the production gate. Option A is not appropriate because a CloudWatch Events rule invoking a Lambda function is an event-driven workaround, not the built-in approval mechanism, and Lambda cannot natively 'wait' for human approval without complex polling. Option D is incorrect because CodeDeploy lifecycle hooks pause during a deployment for scripts or validation, not for a human approval gate before the deployment stage. Option E is incorrect because an SNS topic can notify approvers of a pending approval, but notification alone does not implement the required approval gate.

Answer

Create a CloudWatch Events rule to trigger a Lambda function that waits for approval.

Answer

Use a CodeDeploy lifecycle hook to pause the deployment.

Answer

Configure an SNS topic to send an email to the approver.

Question 8

A developer is using AWS CodeDeploy to deploy an application to an Auto Scaling group. The deployment is set to use a 'OneAtATime' deployment configuration. The developer wants to ensure that the deployment does not cause downtime. Which TWO configurations are necessary?

Accepted Answer

Configure a load balancer for the Auto Scaling group.. Registering the Auto Scaling group with a load balancer allows CodeDeploy to deregister each instance before deployment and re-register it after the new application version is installed and passes health checks. This ensures traffic is shifted away from the instance being updated, preventing downtime during a 'OneAtATime' deployment.

Answer

Set the 'IgnoreApplicationStopFailures' flag to true.

Answer

Use an 'AllAtOnce' deployment configuration.

Answer

Install the CodeDeploy agent on each instance.

Question 9

A development team is using AWS Elastic Beanstalk to deploy a web application. The team wants to perform a blue/green deployment. Which THREE steps are required to complete the blue/green deployment?

Accepted Answer

Swap the CNAMEs of the two environments.. Elastic Beanstalk blue/green deployment requires creating a completely new environment rather than updating the existing one, so option E (deploy the new application version to a separate Elastic Beanstalk environment) is correct because the new version must run in its own environment alongside the original. Option B (swap the CNAMEs of the two environments) is correct because Elastic Beanstalk's Swap Environment URLs feature exchanges the CNAMEs so that the environment URL users already use now resolves to the new environment, redirecting traffic without DNS changes. Option C (terminate the old environment after verifying the new environment) is correct because once the swap is validated and the new environment is healthy, the original environment is no longer needed and should be terminated to avoid unnecessary resource charges. Option A is incorrect because updating the existing environment in place is a rolling/all-at-once deployment, not blue/green, and would not provide an instant rollback path. Option D is incorrect because Elastic Beanstalk blue/green uses the built-in CNAME swap rather than manually editing a Route 53 DNS record.

Answer

Update the existing environment with the new version.

Answer

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

Question 10

A company uses AWS CodeDeploy to deploy a web application to an Auto Scaling group. The deployment fails with the error 'The overall deployment failed because too many individual instances failed deployment'. The deployment configuration is CodeDeployDefault.AllAtOnce. What is the most likely cause?

Accepted Answer

The new application revision contains an error that prevents it from running.. The error 'too many individual instances failed deployment' with the AllAtOnce deployment configuration indicates that the deployment failed on all instances simultaneously. The most likely cause is that the new application revision contains an error that prevents it from running, such as a syntax error, missing dependency, or misconfiguration. Since AllAtOnce deploys to all instances at once, a faulty revision causes all to fail.

Answer

The application is not running on the instances before the deployment.

Answer

The Auto Scaling group has more than 100 instances.

Answer

The deployment group is not associated with the correct Amazon EC2 instances.

Question 11

A developer needs to deploy a serverless application using AWS CloudFormation. The application includes an AWS Lambda function, an Amazon API Gateway REST API, and an Amazon DynamoDB table. The developer wants to create a stack that can be updated without downtime. Which CloudFormation feature should be used?

Accepted Answer

Change Sets. Change Sets allow you to preview how changes to your CloudFormation stack will affect your running resources before you apply them. By reviewing the change set, you can ensure that the update does not cause downtime, for example by replacing resources without interruptions. This makes Change Sets the appropriate feature for updating a stack without downtime.

Answer

Drift detection

Answer

StackSets

Answer

Nested stacks

Question 12

A developer is using AWS Elastic Beanstalk to deploy a Python web application. The application requires a specific version of a Python package that is not pre-installed on the Elastic Beanstalk platform. How should the developer ensure the package is installed on all environment instances?

Accepted Answer

Add the package to a requirements.txt file and deploy it with the application source bundle.. AWS Elastic Beanstalk natively supports Python package management. If you include a `requirements.txt` file in the root directory of your source bundle, Elastic Beanstalk automatically installs the specified packages (and their specific versions, e.g., `package==1.2.3`) using `pip` during the deployment process. While `.ebextensions` can run custom commands, using it to install Python packages is non-standard, complex (due to virtual environment paths on Amazon Linux 2/2023), and unnecessary.

Answer

Use the AWS CLI to run a script on each instance after deployment.

Answer

Include a .ebextensions configuration file that runs a command to install the package.

Answer

Create a custom Dockerfile and use the Docker platform in Elastic Beanstalk.

Question 13

A company uses AWS CloudFormation to manage its infrastructure. The developer wants to update a stack but only if the update does not cause any resource replacement. Which CloudFormation stack update option should be used?

Accepted Answer

Create a change set and review the changes before executing it.. A change set allows you to preview the changes that CloudFormation will make to your stack, including whether any resources will be replaced. By reviewing the change set, you can see if any resource replacement is listed and choose not to execute it if you want to avoid replacements. This gives you full control to update the stack only when no replacements are required.

Answer

Use the direct update option with a template.

Answer

Use the 'Force rollback' option to ensure no replacement.

Answer

Use the 'Preserve stack settings' option when updating the stack.

Question 14

A developer is deploying an application on Amazon ECS using the Fargate launch type. The application needs to read configuration data from an Amazon S3 bucket. How should the developer securely provide the S3 bucket name to the container at runtime?

Accepted Answer

Define an environment variable in the ECS task definition with the bucket name.. Defining an environment variable in the ECS task definition is the simplest and most secure way to inject the S3 bucket name into the container at runtime. Environment variables are passed to the container when it starts, and they can be stored in the task definition itself or referenced from AWS Secrets Manager or Systems Manager Parameter Store for sensitive values. This approach avoids hardcoding and keeps the configuration decoupled from the application code.

Answer

Hardcode the bucket name in the application code.

Answer

Use AWS Systems Manager Parameter Store and retrieve the bucket name at startup.

Answer

Store the bucket name in the container image's environment file.

Question 15

A team uses AWS CodeBuild to run automated tests. The buildspec.yaml file contains a 'pre_build' phase that sets environment variables. During a build, the build fails with 'Error: Cannot find module 'express' when running a Node.js application. The application's package.json is in the source root. What is the most likely cause?

Accepted Answer

The buildspec does not include a command to run 'npm install' in the install or pre_build phase.. AWS CodeBuild runs each phase in the buildspec in order: install, pre_build, build, post_build. If the buildspec does not include an 'npm install' (or 'npm ci') command in the install or pre_build phase, the Node.js dependencies listed in package.json — including express — are never downloaded into node_modules. The build then fails when it tries to require('express'). The fix is to add 'npm install' to the install phase.

Answer

The Node.js runtime version is incompatible with the express module.

Answer

The environment variable NODE_ENV is set to production, which skips devDependencies.

Answer

The package.json file is not in the source root directory.