DVA-C02 Deployment Practice Test 3 — 15 Questions

Question 1

A company is deploying a Node.js application on AWS Elastic Beanstalk. The application uses environment variables for configuration. The development team wants to ensure that the environment variables are not exposed in the source code or in the deployment logs. Which TWO actions should the team take? (Choose TWO.)

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

Accepted Answer

Store sensitive environment variables in AWS Systems Manager Parameter Store and retrieve them at runtime.. Option C is correct because AWS Systems Manager Parameter Store provides a secure, centralized place to store configuration data and secrets, and the Node.js application can retrieve them at runtime using the AWS SDK or the Parameter Store API, keeping them out of source code and deployment logs. Option D is correct because AWS Secrets Manager is purpose-built for managing sensitive values such as credentials and API keys, and referencing secrets in code via the Secrets Manager API or SDK means the actual values are never embedded in the application package or printed in deployment logs. Option A is not appropriate because enabling detailed logging and filtering sensitive data still risks exposure and does not prevent secrets from being present in the environment or logs. Option B is not sufficient because Elastic Beanstalk environment properties are visible in the console and may appear in configuration outputs, so they do not meet the requirement of keeping sensitive values out of source code and logs. Option E is incorrect because embedding a .env file in the application package places the secrets directly in the deployment artifact, which is exactly what the team wants to avoid.

Answer

Enable detailed logging for the Elastic Beanstalk environment and filter out sensitive data.

Answer

Set environment variables using Elastic Beanstalk environment properties in the console.

Answer

Embed the environment variables in the application package as a .env file.

Question 2

A company is using AWS CloudFormation to deploy a stack with a Lambda function and an API Gateway REST API. The deployment must be updated without downtime. The current stack has a Lambda function with an alias 'prod'. Which THREE steps should the developer take to achieve a zero-downtime deployment? (Choose THREE.)

Accepted Answer

Create a new Lambda function version and assign it to a new alias 'blue'.. Options B, C, and E are correct: Create a new Lambda function version and assign it to a new alias 'blue' (B), use AWS CodeDeploy to gradually shift traffic from the 'prod' alias to the 'blue' alias (C), and update the API Gateway stage to point to the 'blue' alias for testing (E). This approach achieves zero downtime by not modifying the 'prod' alias until traffic is shifted. Option A (updating the existing 'prod' alias directly) would cause immediate downtime as the old version is replaced without testing. Option D (deleting the old version) is not necessary during the update and could disrupt rollback.

Answer

Update the existing 'prod' alias to point to the new function version.

Answer

Delete the old Lambda function version after the update.

Question 3

A development team uses AWS Elastic Beanstalk for a Node.js application. They want to deploy a new version with zero downtime. Which deployment policy should they choose?

Accepted Answer

Immutable. (Immutable). Immutable deployment launches a completely new Auto Scaling group with the new version, then swaps the CNAME record to point to the new environment. This ensures zero downtime because the old environment remains active until the cutover is complete. Option B (All at once) replaces all instances simultaneously, causing downtime. Option C (Rolling) updates instances in batches, reducing capacity during the update and potentially causing downtime. Option D (Rolling with additional batch) adds extra instances before rolling, but still has a brief period where capacity is reduced and zero downtime is not guaranteed.

Answer

All at once

Answer

Rolling

Answer

Rolling with additional batch

Question 4

A company wants to deploy a microservices application on Amazon ECS. They need to update services with zero downtime and automatic rollback on failure. Which deployment controller should they use?

Accepted Answer

Rolling update (ECS default). The ECS rolling update deployment controller (the default) supports zero-downtime deployments by gradually replacing tasks, and it can be configured with automatic rollback on failure using CloudWatch alarms. This meets the requirement without needing additional services. Blue/green deployment is not a native ECS deployment controller; it requires CodeDeploy. Therefore, the rolling update is the correct choice.

Answer

External deployment controller

Answer

Daemon scheduling strategy

Answer

Blue/green deployment

Question 5

A developer is using AWS CloudFormation to deploy a stack that includes an Amazon RDS DB instance. The developer wants to update the DB instance to a larger instance type without causing downtime. The current template has DeletionPolicy set to 'Delete'. What should the developer do?

Accepted Answer

Use a blue/green deployment by creating a new stack with the larger instance type and updating the application to point to the new database.. A blue/green deployment allows you to create a new stack with the larger DB instance type in a separate environment (green), then switch the application traffic to the new database with minimal downtime. This approach avoids the downtime associated with in-place modifications, as CloudFormation updates to RDS instance types typically require a reboot, which causes an outage. By using a blue/green deployment, the developer can validate the new instance and cut over seamlessly.

Answer

Take a snapshot of the DB instance and restore it to a larger instance type.

Answer

Change the DeletionPolicy to 'Retain' and update the stack.

Answer

Create a read replica with the larger instance type and promote it.

Question 6

A developer is deploying a Python application to AWS Lambda. The application has several dependencies. The developer wants to ensure that the deployment package is as small as possible to reduce cold start times. What should the developer do?

Accepted Answer

Use Lambda Layers to manage dependencies separately from the function code.. Lambda Layers allow you to package and manage dependencies (like Python libraries) separately from your function code. By moving shared dependencies to a layer, the individual function code deployment packages become smaller, and the dependencies can be easily shared across multiple functions. Note that while layers make deployment packages smaller and allow console editing, they do not reduce cold start times because Lambda still has to download and extract the layers during a cold start.

Answer

Use an S3 bucket to store the deployment package.

Answer

Use AWS CodeBuild to optimize the package.

Answer

Include all dependencies in the deployment package.

Question 7

A developer is using AWS CodePipeline to deploy a web application. The pipeline has a source stage from Amazon S3, a build stage using AWS CodeBuild, and a deploy stage using AWS CodeDeploy. The developer notices that the deploy stage fails intermittently due to EC2 instances not being available. Which TWO actions should the developer take to improve the reliability of the deployment? (Choose two.)

Accepted Answer

Configure the CodeDeploy deployment group to have a minimum healthy hosts threshold.. Option B is correct because configuring a minimum healthy hosts threshold in the CodeDeploy deployment group ensures that CodeDeploy only proceeds when a specified number or percentage of instances remain healthy and available, preventing intermittent failures caused by instances being temporarily unavailable during deployment. Option E is correct because adding a manual approval step before the deploy stage lets the developer verify that the target EC2 instances are healthy and available before CodeDeploy begins, directly addressing the intermittent availability issue and improving deployment reliability. Option A is not appropriate because simply increasing the number of EC2 instances does not guarantee that CodeDeploy will wait for or verify instance availability, and it does not fix the underlying deployment configuration issue. Option C is incorrect because reducing the deployment timeout would cause deployments to fail faster, not more reliably, and could increase intermittent failures. Option D is incorrect because switching to blue/green deployment changes the deployment strategy but does not by itself ensure that instances are available before deployment begins, and it may not be suitable or sufficient for the stated intermittent availability problem.

Answer

Increase the number of EC2 instances in the Auto Scaling group to ensure availability.

Answer

Reduce the deployment timeout to fail faster.

Answer

Use a different deployment type, such as blue/green, instead of in-place.

Question 8

A company is deploying a containerized application on Amazon ECS using AWS Fargate. The application needs to handle variable traffic. The developer wants to set up automatic scaling based on CPU utilization. Which THREE steps are required to achieve this? (Choose three.)

Accepted Answer

Create a CloudWatch alarm for CPUUtilization metric.. Option B is correct because Application Auto Scaling for ECS target tracking relies on a CloudWatch alarm that monitors the service's CPUUtilization metric and triggers scaling actions when the threshold is breached. Option D is correct because the ECS service must first be registered as a scalable target with Application Auto Scaling, which defines the minimum and maximum task count boundaries that scaling can operate within. Option E is correct because a target tracking scaling policy must be created and attached to the scalable target, specifying the target CPU utilization percentage (for example, 70%) that ECS will maintain by adjusting the desired task count. Option A is incorrect because setting a static desired count defeats the purpose of automatic scaling; the desired count must be dynamically managed by the scaling policy, not fixed. Option C is incorrect because while CPU and memory limits are defined in the task definition for task placement and sizing, they are not a required step for configuring automatic scaling itself.

Answer

Update the ECS service to set the desired count to a static value.

Answer

Define a task definition with CPU and memory limits.

Question 9

A company is deploying a new microservice using AWS CodeDeploy. The deployment group uses an EC2/On-Premises compute platform with an in-place deployment configuration. After the deployment, the new application version is not receiving traffic. The previous version continues to serve requests. What is the most likely cause?

Accepted Answer

The deployment group is not associated with a load balancer or target group.. During an in-place deployment on EC2 instances behind an Application Load Balancer (ALB), CodeDeploy can prevent traffic from being routed to instances while they are being updated. To do this, the deployment group must be explicitly associated with the ALB's target group. If this association is missing, CodeDeploy will perform the deployment without deregistering the instances from the target group. Consequently, the load balancer continues to route user traffic to the instances while the application is stopped and updated, resulting in 502 Bad Gateway errors.

Answer

The application revision is not stored in the correct S3 bucket.

Answer

The deployment configuration is set to CodeDeployDefault.OneAtATime.

Answer

The CodeDeploy agent is not installed on the EC2 instances.

Question 10

A company uses AWS CloudFormation to deploy infrastructure. They have a stack that creates an Amazon RDS DB instance. They want to update the DB instance class without downtime. Which update policy should they use?

Accepted Answer

UseLatestRestorableTime. None of the listed options is correct. AWS CloudFormation does not have a built-in update policy that avoids downtime when changing the DB instance class of an RDS instance. To modify the instance class with minimal downtime, you can use a custom approach such as creating a read replica, promoting it, and updating DNS, or modifying the DB instance directly (which typically involves brief downtime). The options presented are either invalid or unrelated: UseLatestRestorableTime is a property for restoring from a snapshot or creating read replicas, not an update policy; AutoScalingRollingUpdate is for Auto Scaling groups; UpdateReplacePolicy controls replacement behavior; CreationPolicy controls creation signals.

Answer

AutoScalingRollingUpdate

Answer

UpdateReplacePolicy

Answer

CreationPolicy

Question 11

A developer is using AWS CloudFormation to create a stack. They want to update the stack but need to ensure that if the update fails, the stack is automatically rolled back to the previous state. Which stack option should they configure?

Accepted Answer

Set the 'Rollback on failure' option to 'Yes'.. The 'Rollback on failure' option, when set to 'Enabled' in the AWS CloudFormation console, instructs CloudFormation to automatically revert the stack to its previous working state if the stack update fails. Conversely, setting 'Disable rollback' to 'Enabled' (or True) would prevent the stack from rolling back, leaving it in a failed state for troubleshooting.

Answer

Configure SNS notification topics for the stack.

Answer

Set the 'Disable rollback' option to 'No'.

Answer

Define a stack policy that protects critical resources.

Question 12

A team uses AWS Elastic Beanstalk with a Docker platform. They want to deploy a multi-container Docker application. What file is required to define the container configuration?

Accepted Answer

docker-compose.yml. On modern AWS Elastic Beanstalk platforms (Amazon Linux 2 and Amazon Linux 2023), multi-container Docker deployments are configured using a standard `docker-compose.yml` file. The legacy `Dockerrun.aws.json` (v2) was used for the now-retired Multi-container Docker platform on Amazon Linux 1.

Answer

Dockerrun.aws.json

Answer

Dockerfile

Answer

env.yaml

Question 13

A developer runs the AWS CLI command shown in the exhibit. The deployment is created successfully, but the CodeDeploy agent on the target instances does not download the revision. What is the most likely cause?

Accepted Answer

The S3 object version is not specified.. The correct option is D: the S3 object version is not specified. When a CodeDeploy revision is stored in a versioned S3 bucket, the CLI create-deployment command must include the s3Location with both the bucket, key, and bundleType, and critically the version ID (e.g., --s3-location bucket=...,key=...,bundleType=zip,version=...); without the version, CodeDeploy cannot resolve the exact object to download, so the agent fails to fetch the revision even though the deployment itself is created successfully. Options A, B, and C are not the most likely cause: bundleType 'zip' is valid for CodeDeploy, an incorrect bucket name or a misspelled deployment group name would typically cause the create-deployment call to fail or target the wrong group rather than produce a successful deployment where the agent simply cannot download the revision.

Answer

The bundle type should be 'tar' instead of 'zip'.

Answer

The bucket name is incorrect.

Answer

The deployment group name is misspelled.

Question 14

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 template should use AutoPublishAlias to create versions.. In AWS CloudFormation, the AWS::Lambda::Version resource is immutable and its properties (such as FunctionName) do not change when the underlying function's code is updated. Because CloudFormation does not detect any property changes on the AWS::Lambda::Version resource, it does not trigger an update or recreation of that resource. To force CloudFormation to create a new Lambda version, you must change the logical ID of the AWS::Lambda::Version resource (for example, by appending a hash or version number to the logical ID) during the template update.

Answer

The function code changed, but CloudFormation does not detect the change because the S3 key is the same.

Answer

The version resource is created before the function update completes.

Answer

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

Question 15

A company is deploying a new microservice using AWS Lambda. The deployment pipeline uses AWS CodeBuild and AWS CodePipeline. The team wants to automatically roll back to the previous function version if the new version fails CloudWatch alarms. Which deployment strategy should they implement?

Accepted Answer

Canary deployment with a CloudWatch alarm-based rollback. The correct option is A: Canary deployment with a CloudWatch alarm-based rollback. AWS Lambda supports canary deployments through CodeDeploy, where traffic is shifted in increments and CloudWatch alarms can trigger an automatic rollback to the previous function version if the new version fails. This directly matches the requirement to automatically revert when alarms fire. Option B is incorrect because a pre-traffic hook runs validation before traffic shifts but does not provide alarm-based rollback of a Lambda version. Option C is incorrect because immutable deployment is an EC2/on-premises CodeDeploy strategy, not a Lambda traffic-shifting strategy. Option D is incorrect because blue/green with CodeDeploy shifts all traffic at once and does not inherently use CloudWatch alarms for automatic rollback in the same canary manner.

Answer

Rolling update with a pre-traffic hook

Answer

Immutable deployment with an automated rollback

Answer

Blue/Green deployment with an AWS CodeDeploy configuration