DVA-C02 Deployment — Timed 50 Questions

Question 1

A developer is using AWS CodeDeploy with a blue/green deployment strategy to update an application running on Amazon ECS with the Fargate launch type. After the new (green) task set is created and traffic is shifted to it, users immediately report errors when trying to write data. The developer discovers that the green task set is connecting to a different database than the blue task set. The database endpoints are configured in the ECS task definition. What is the simplest way to prevent this issue in future deployments?

Accepted Answer

Modify the blue/green deployment configuration to use the same database endpoint for both task sets by updating the environment variables in the task definition before deployment.. Option A is correct because the issue stems from the green task set using a different database endpoint than the blue task set, which is configured via environment variables in the ECS task definition. By updating the task definition to use the same database endpoint before deployment, both task sets will connect to the same database, ensuring consistency during the traffic shift. This is the simplest fix as it requires no additional infrastructure or complex routing changes.

Answer

Create two separate Amazon RDS databases and use an Amazon Route 53 weighted routing policy to distribute traffic.

Answer

Use an Application Load Balancer (ALB) with stickiness to route each user to the correct task set.

Answer

Use AWS CloudFormation to create a new database stack for each deployment and update the task definition dynamically.

Question 2

A developer is using AWS CodeDeploy with a blue/green deployment on an Amazon ECS service running on Fargate. The developer wants to ensure that the new (green) task set is fully healthy and serving traffic before the old (blue) task set is terminated. The deployment should automatically roll back to the blue task set if the green task set fails health checks. Which configuration should the developer set in the CodeDeploy deployment group?

Accepted Answer

Deployment type: blue/green, with rollback configuration enabled to trigger automatic rollback and reroute traffic to the original task set. Option A is correct because the developer needs to configure the CodeDeploy deployment group with a blue/green deployment type and enable automatic rollback. This ensures that if the green task set fails health checks, CodeDeploy automatically terminates the green deployment and reroutes traffic back to the original blue task set, meeting the requirement for a fully healthy green task set before termination.

Answer

Deployment type: blue/green, Deployment configuration: CodeDeployDefault.ECSAllAtOnce

Answer

Deployment type: blue/green, Deployment configuration: CodeDeployDefault.ECSLinear10PercentEvery1Minutes

Answer

Deployment type: blue/green, with an Application Load Balancer

Question 3

A developer is deploying a serverless application using the AWS Serverless Application Model (SAM). The application includes an Amazon API Gateway HTTP API and several AWS Lambda functions. The developer wants to implement a canary deployment for the API Gateway stage so that 10% of traffic is shifted to the new version for 30 minutes before the remaining 90% is shifted. Which SAM resource attribute should the developer configure on the API Gateway resource?

Accepted Answer

DeploymentPreference. The `DeploymentPreference` attribute on an AWS::Serverless::Api resource in SAM enables canary deployments by allowing you to specify traffic-shifting patterns, such as `Canary10Percent30Minutes`. This shifts 10% of traffic to the new API Gateway stage for 30 minutes before rolling out the remaining 90%, exactly matching the requirement.

Answer

AutoPublishAlias

Answer

ProvisionedConcurrencyConfig

Answer

EventInvokeConfig

Question 4

A developer is deploying a multi-container Docker application on Amazon ECS using the Fargate launch type. The application consists of a web server and a background worker. The web server must be scaled independently and must be accessible from the internet via an Application Load Balancer. The worker should not be accessible from the internet. Which ECS configuration should the developer use?

Accepted Answer

Create two separate ECS services, each with its own task definition, and place the web server in a public subnet with the worker in a private subnet.. Option B is correct because it uses two separate ECS services, each with its own task definition, allowing independent scaling of the web server and worker. Placing the web server in a public subnet with an Application Load Balancer makes it internet-accessible, while the worker in a private subnet is isolated from direct internet traffic, meeting the security requirement.

Answer

Create one ECS service with both containers in the same task definition, but only expose the web server port.

Answer

Create one ECS service with two tasks, each containing one container.

Answer

Create one ECS service with two containers in the same task, and use a service discovery to expose the worker.

Question 5

A developer is using AWS CodeDeploy to deploy an application to an EC2 Auto Scaling group. The application must remain fully available; only one instance should be taken offline at a time. The developer wants to configure the deployment to update instances one by one, ensuring that the deployment fails fast if any instance fails to deploy. Which deployment configuration should the developer choose?

Accepted Answer

CodeDeployDefault.OneAtATime. Option C, CodeDeployDefault.OneAtATime, is correct because it deploys the application to one instance at a time, ensuring that only one instance is taken offline during the deployment. This satisfies the requirement for the application to remain fully available. Additionally, this configuration fails fast: if any instance fails to deploy, the deployment stops immediately, preventing further instances from being updated.

Answer

CodeDeployDefault.AllAtOnce

Answer

CodeDeployDefault.HalfAtATime

Answer

CodeDeployDefault.BlueGreen

Question 6

A developer is deploying an application to Amazon ECS using AWS CodeDeploy with a blue/green deployment strategy. After the new task set is created, it fails health checks. The developer wants to immediately route traffic back to the original task set without waiting for CodeDeploy to complete the rollback process. Which action should the developer take?

Accepted Answer

Use the CodeDeploy console to stop the deployment and then choose to reroute traffic.. Option B is correct because CodeDeploy's blue/green deployments for ECS include a built-in 'Reroute traffic' option that allows you to immediately redirect traffic back to the original task set when a deployment fails health checks. This action bypasses the normal rollback process, which would wait for the deployment to complete or for the configured rollback triggers to fire, giving the developer instant control over traffic routing.

Answer

Update the ECS service to set the desired count of the new task set to zero.

Answer

Delete the new task set.

Answer

Update the Application Load Balancer listener rule to forward traffic to the original target group.

Question 7

A developer is deploying a new version of a web application to an EC2 Auto Scaling group using AWS CodeDeploy with a blue/green deployment strategy. The Auto Scaling group is associated with an Application Load Balancer (ALB). The developer wants to ensure that the new instances are registered with the ALB and pass health checks before any traffic is routed to them. Which CodeDeploy configuration should the developer use?

Accepted Answer

Set the 'Reroute traffic to replacement instances' to 'Wait for health check' and specify the ELB health check.. Option C is correct because setting 'Reroute traffic to replacement instances' to 'Wait for health check' and specifying the ELB health check ensures that CodeDeploy waits for the new instances to pass the ALB health checks before rerouting traffic. This aligns with the requirement that new instances must be registered and healthy before receiving traffic, preventing downtime or routing to unhealthy targets.

Answer

Set the 'Reroute traffic to replacement instances' to 'Immediately'.

Answer

Set the 'Reroute traffic to replacement instances' to 'Wait for time' and specify a wait time.

Answer

Set the deployment to terminate the original instances before rerouting traffic.

Question 8

A developer is using AWS CodeDeploy to deploy an application to an Auto Scaling group of EC2 instances. The application is critical and must have zero downtime. The Auto Scaling group currently has 4 instances spread across 2 Availability Zones. Which predefined deployment configuration minimizes the number of instances taken out of service at any given time?

Accepted Answer

CodeDeployDefault.OneAtATime. Option C, CodeDeployDefault.OneAtATime, is correct because it deploys the application to only one instance at a time, ensuring that the remaining instances continue to serve traffic. This minimizes the number of instances taken out of service at any given moment, which is critical for achieving zero downtime in an Auto Scaling group with 4 instances across 2 Availability Zones.

Answer

CodeDeployDefault.AllAtOnce

Answer

CodeDeployDefault.HalfAtATime

Answer

CodeDeployDefault.LambdaCanary10Percent5Minutes

Question 9

A company uses AWS Elastic Beanstalk to run a web application. They want to deploy a new version with zero downtime and roll forward if successful. They have two environments: a production environment (current version) and a staging environment (new version). After verifying the staging environment, they want to swap the URLs so that production now points to the new version. Which deployment strategy should they use?

Accepted Answer

Blue/green deployment with environment CNAME swap. Option A is correct because blue/green deployment with an environment CNAME swap allows you to run two separate Elastic Beanstalk environments (production and staging) simultaneously. After verifying the new version in the staging environment, you swap the CNAME records so that the production URL points to the staging environment, achieving zero downtime and a roll-forward strategy. This approach decouples the deployment from the existing environment, ensuring no disruption to live traffic during the swap.

Answer

All at once deployment

Answer

Rolling deployment with additional batch

Answer

Immutable deployment

Question 10

A developer is using AWS Elastic Beanstalk to deploy a web application. The application requires a highly available environment across multiple Availability Zones. The developer wants to update the application without any downtime while minimizing the number of new instances launched. Which deployment policy should the developer use?

Accepted Answer

Rolling with additional batch. Option C (Rolling with additional batch) is correct because it launches a new batch of instances before taking the old ones out of service, ensuring full capacity is maintained during the deployment. This provides high availability across multiple Availability Zones while minimizing the number of new instances compared to an immutable deployment, which would double the instance count. The additional batch absorbs the traffic during the rolling update, preventing any downtime.

Answer

All at once

Answer

Rolling

Answer

Immutable

Question 11

A developer is deploying a microservices application on Amazon ECS with the Fargate launch type. The application uses an Application Load Balancer (ALB) to route traffic. The developer wants to perform a blue/green deployment with automated traffic shifting using AWS CodeDeploy. What is the minimum number of target groups required for this deployment?

Accepted Answer

Two. In a blue/green deployment with AWS CodeDeploy and an Application Load Balancer (ALB) on Amazon ECS (Fargate), two target groups are required: one for the 'blue' (current) environment and one for the 'green' (new) environment. CodeDeploy shifts traffic from the blue target group to the green target group by updating the ALB listener rules, allowing zero-downtime deployments and automated rollback if needed.

Answer

One

Answer

Three

Answer

Four

Question 12

A developer is using AWS CodeDeploy to deploy an application to an Amazon ECS service with the Fargate launch type. The deployment uses a blue/green strategy. After the new task set is created and passes the initial health checks, the traffic is shifted to the new task set. However, the new task set is immediately replaced by the old one after a few minutes, causing a rollback. What is the most likely reason?

Accepted Answer

The new task set fails the post-traffic shift validation tests.. Option D is correct because in a blue/green deployment on ECS with CodeDeploy, after traffic is shifted to the new task set, CodeDeploy runs post-traffic shift validation tests (e.g., via Lambda hooks or target group health checks). If these tests fail, CodeDeploy automatically triggers a rollback by replacing the new task set with the original (old) task set. This matches the described behavior where the new task set is immediately replaced after a few minutes.

Answer

The lifecycle hooks for the new task set are failing.

Answer

The target group for the new task set is not configured correctly.

Answer

The deployment group's rollback configuration triggers due to alarm threshold.

Question 13

A developer is deploying a microservice using AWS CodeDeploy with an Amazon ECS compute platform. The service must be updated with a blue/green deployment strategy. The developer wants to ensure that if the deployment fails, the new task set is automatically terminated and the original task set continues to serve traffic. Which configuration should the developer set?

Accepted Answer

Set the deployment group's 'Rollback configuration' to automatically roll back failed deployments and configure the 'Deployment configuration' to terminate the original task set on success, but keep it on failure.. Option C is correct because AWS CodeDeploy for Amazon ECS blue/green deployments allows you to configure automatic rollback on failure within the deployment group settings. By enabling 'Rollback configuration' to automatically roll back failed deployments and setting the 'Deployment configuration' to terminate the original task set only on success (keeping it on failure), you ensure that if the deployment fails, the new task set is automatically terminated and the original task set continues to serve traffic. This directly meets the requirement without manual intervention.

Answer

Set the deployment configuration to 'AllAtOnce' and enable termination of the original task set

Answer

Define a blue/green deployment using an AppSpec file with a 'Hooks' section to specify a 'BeforeAllowTraffic' hook that checks health. If the check fails, CodeDeploy automatically rolls back.

Answer

Use a manual approval step in the pipeline to decide whether to terminate the new task set.

Question 14

A company deploys a serverless application using AWS SAM. The application includes an Amazon API Gateway HTTP API and several AWS Lambda functions. The developer wants to implement a canary deployment for the API Gateway stage: 5% of traffic should be immediately shifted to the new version, and after 15 minutes, the remaining 95% should be shifted. Which SAM resource attribute should the developer configure?

Accepted Answer

DeploymentPreference with Type: Canary5Percent15Minutes. Option B is correct because AWS SAM's DeploymentPreference attribute with Type: Canary5Percent15Minutes shifts 5% of traffic to the new version immediately, then automatically shifts the remaining 95% after 15 minutes, exactly matching the requirement. This is a built-in canary deployment strategy for API Gateway stages when using SAM's AutoPublishAlias and DeploymentPreference features.

Answer

DeploymentPreference with Type: Canary10Percent30Minutes

Answer

DeploymentPreference with Type: Linear10PercentEvery10Minutes

Answer

DeploymentPreference with Type: AllAtOnce

Question 15

A developer is using AWS SAM to define a serverless application. The application includes an AWS Lambda function and an Amazon API Gateway REST API. The developer wants to configure the API Gateway stage to enable logging and set the stage name based on the SAM parameter Stage. In the SAM template, which property of the AWS::Serverless::Api resource should the developer use to set the stage name?

Accepted Answer

StageName. The `StageName` property of the `AWS::Serverless::Api` resource directly sets the stage name for the API Gateway REST API. By using a SAM parameter like `Stage` (e.g., `StageName: !Ref Stage`), the developer can dynamically control the stage name at deployment time. This is the intended and simplest way to configure the stage name in an AWS SAM template.

Answer

DefinitionBody

Answer

StageDescription

Answer

EndpointConfiguration

Question 16

A developer is using AWS CodeDeploy to deploy an application to an Auto Scaling group. The deployment must be as fast as possible while ensuring that at least 50% of instances remain healthy throughout. Which deployment configuration should be used?

Accepted Answer

CodeDeployDefault.HalfAtATime. CodeDeployDefault.HalfAtATime is the correct choice because it deploys to half of the instances in the Auto Scaling group at a time, ensuring that at least 50% of instances remain healthy throughout the deployment. This configuration balances speed (by deploying to multiple instances concurrently) with the required availability constraint, making it the fastest option that satisfies the 'at least 50% healthy' requirement.

Answer

CodeDeployDefault.OneAtATime

Answer

CodeDeployDefault.AllAtOnce

Answer

CodeDeployDefault.MinHealthyPercent

Question 17

A developer uses AWS CodePipeline to deploy a serverless application defined with AWS SAM. The pipeline consists of Source (S3), Build (CodeBuild), and Deploy (CloudFormation) stages. The developer wants to run integration tests after the stack is deployed but before the pipeline completes. Which approach should the developer use?

Accepted Answer

Add a test stage after the Deploy stage with an action that invokes a Lambda function to run tests.. Option A is correct because AWS CodePipeline allows you to add a test stage after the Deploy stage, and you can configure an action that invokes an AWS Lambda function to run integration tests. This ensures tests run automatically after the CloudFormation stack is deployed but before the pipeline completes, meeting the requirement without manual intervention.

Answer

Use the CloudFormation stack's Outputs to trigger a Lambda function that runs tests.

Answer

Configure a post-deployment hook in the SAM template that runs tests.

Answer

Add a manual approval step after Deploy, then run tests manually.

Question 18

A developer is using AWS CodeDeploy to deploy an application to an EC2 Auto Scaling group. The developer wants the deployment to automatically roll back if any of the new instances fail a health check within the first 10 minutes after deployment. Which configuration should the developer set in the CodeDeploy deployment group?

Accepted Answer

Configure a CloudWatch alarm and enable alarm-based automatic rollback in the AutoRollbackConfiguration.. Option A is correct because CodeDeploy's AutoRollbackConfiguration allows you to specify CloudWatch alarms as triggers for automatic rollback. By creating a CloudWatch alarm that monitors the EC2 Auto Scaling group's health check failures and setting the alarm's evaluation period to 10 minutes, the deployment will automatically roll back if any new instance fails a health check within that window. This directly meets the requirement without custom scripting or manual intervention.

Answer

Set the DeploymentStyle to 'BLUE_GREEN' and configure the 'LoadBalancerInfo' with the target group.

Answer

Create a lifecycle hook for the Auto Scaling group to trigger a rollback script.

Answer

Set a TriggerConfiguration in the deployment group to send notifications on deployment failure.

Question 19

A developer is using AWS Elastic Beanstalk to deploy a web application. The application uses an in-environment Amazon RDS database instance. The developer needs to update the application code without risking data loss. The database must not be affected by environment operations such as termination or updates. What is the recommended approach?

Accepted Answer

Create a standalone Amazon RDS instance and reconfigure the application to use it instead of the in-environment database.. Option A is correct because decoupling the RDS database from the Elastic Beanstalk environment by creating a standalone RDS instance ensures that the database is not tied to the environment's lifecycle. In-environment databases are automatically deleted when the environment is terminated or updated, risking data loss. By reconfiguring the application to point to an external RDS instance, the database persists independently of environment operations, meeting the requirement to avoid data loss during code updates or environment changes.

Answer

Take a snapshot of the database before each deployment and restore it after the deployment completes.

Answer

Use the Elastic Beanstalk environment's 'Swap environment URLs' feature to perform a blue/green deployment.

Answer

Create a new Elastic Beanstalk environment with a new RDS instance and migrate data manually.

Question 20

A developer is using AWS CodePipeline with a two-stage pipeline: Source (CodeCommit) and Deploy (Elastic Beanstalk). The developer wants to add a test stage that runs unit tests using AWS CodeBuild. The test stage should run only when a specific branch (development) is pushed. Which approach should the developer use?

Accepted Answer

Add a test stage in the pipeline and configure a 'branch' filter on the source action to only trigger for the development branch.. Option B is correct because AWS CodePipeline allows you to configure a 'branch' filter directly on the source action (CodeCommit) to restrict which branch triggers the pipeline execution. By adding a test stage with a CodeBuild action and setting the source action's 'Branch' filter to 'development', the pipeline will only run the test stage when changes are pushed to that specific branch. This is the simplest and most native approach, requiring no additional compute or manual intervention.

Answer

Create a separate pipeline for the development branch and configure it with the test stage.

Answer

Add a test stage in the pipeline and configure a 'branch' condition on the test action using a Lambda function.

Answer

Add a test stage in the pipeline and use a 'Manual approval' action that requires a human to verify the branch.