DVA-C02 Practice Exam 65 — 20 Questions

Question 1

A developer is using AWS CodeDeploy to perform a canary deployment for an AWS Lambda function. The deployment should first shift 10% of traffic to the new version, and then shift the remaining 90% after 5 minutes. Which deployment configuration should be used?

Accepted Answer

Canary10Percent5Minutes. Option B is correct because the Canary10Percent5Minutes deployment configuration is specifically designed for canary deployments with AWS Lambda, shifting 10% of traffic to the new version immediately and then automatically shifting the remaining 90% after a 5-minute interval. This matches the requirement exactly, as CodeDeploy uses this predefined configuration to orchestrate the traffic shift in two steps with a built-in wait period.

Answer

AllAtOnce

Answer

Linear10PercentEvery10Minutes

Answer

BlueGreen

Question 2

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 3

A developer needs different configuration values for dev, test, and prod in the same SAM template. Which feature is suitable?

Accepted Answer

Parameters and environment-specific parameter overrides. AWS SAM supports Parameters and environment-specific parameter overrides, allowing you to define a single template and supply different configuration values (e.g., database URLs, API keys) for dev, test, and prod environments at deployment time. This is achieved by passing a JSON or YAML file with the `--parameter-overrides` flag in the `sam deploy` command, or by using the `parameters` section in a `samconfig.toml` file. This approach avoids duplicating templates and keeps infrastructure-as-code DRY and maintainable.

Answer

Hardcoded ARNs in every function

Answer

One AWS root account per environment

Answer

Disabling stack updates

Question 4

A developer is using AWS Elastic Beanstalk to deploy a web application. The developer wants to run database migration scripts as part of the deployment process before the new application version starts serving traffic. Which Elastic Beanstalk configuration file should the developer use to define the migration commands?

Accepted Answer

.ebextensions/.config with container_commands. Option A is correct because `container_commands` in `.ebextensions/.config` runs commands after the application and web server have been set up but before the new application version starts serving traffic. This makes it the ideal place to execute database migration scripts that must complete before the environment accepts requests, ensuring data consistency.

Answer

.ebextensions/<filename>.config with commands

Answer

Procfile

Answer

buildspec.yml

Question 5

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 6

A developer wants to deploy a serverless application using AWS CloudFormation. The application consists of an API Gateway, Lambda functions, and DynamoDB tables. The developer wants to ensure that the stack can be updated without resource interruption when possible. Which CloudFormation feature should the developer use?

Accepted Answer

Use a Lambda alias with a DeploymentPreference update policy. Option A is correct because the `DeploymentPreference` update policy on a Lambda alias enables canary, linear, or all-at-once traffic shifting during stack updates. This allows the developer to update Lambda function versions without interrupting existing invocations, as traffic is gradually routed to the new version while the old version continues to serve requests until the transition completes.

Answer

Use a ChangeSet to review changes before applying them

Answer

Use a StackPolicy to protect critical resources

Answer

Use a Custom Resource to manage updates

Question 7

A company uses AWS Elastic Beanstalk to run a web application. They want to deploy a new version with zero downtime. They have a production environment running the current version and a staging environment running the new version. After thoroughly testing 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 CNAME swap. Blue/green deployment with a CNAME swap is the correct strategy because it allows you to run two identical environments (blue = current production, green = new version) and switch traffic atomically by updating the DNS CNAME record. This achieves zero downtime since the production environment remains active until the swap is complete, and the staging environment has been fully tested. Elastic Beanstalk supports this by letting you perform a CNAME swap between environments via the console, CLI, or API.

Answer

Rolling deployment

Answer

Immutable deployment

Answer

All at once deployment

Question 8

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 9

A CloudFormation update may replace an RDS database. The developer wants to preview replacement risk before executing. What should be created?

Accepted Answer

A change set. A change set in AWS CloudFormation allows you to preview how proposed changes to a stack will be executed, including whether any resources will be replaced (e.g., an RDS database). By reviewing the change set, you can see if the update will cause replacement (indicated by 'Replacement: True') before you actually apply the changes, enabling risk assessment without modification.

Answer

A stack policy only

Answer

A nested stack output

Answer

A CloudWatch dashboard

Question 10

A CodeDeploy blue/green ECS deployment uses an ALB. Which two resources are required?

Accepted Answer

Two target groups for original and replacement task sets. Option A is correct because a blue/green deployment in CodeDeploy for ECS requires two distinct target groups: one for the original (blue) task set and one for the replacement (green) task set. The ALB routes traffic to the appropriate target group based on the listener rules, allowing CodeDeploy to shift traffic gradually from the blue to the green task set during deployment.

Answer

A single target group shared by both task sets only

Answer

An S3 static website endpoint

Question 11

A developer has set up an AWS CodePipeline pipeline that automatically deploys a web application through a series of stages: Source, Build, Staging, and Production. The developer wants to require a manual approval before the pipeline proceeds to the Production stage. How should the developer implement this?

Accepted Answer

Add a manual approval action between the Staging and Production stages. Option B is correct because AWS CodePipeline supports manual approval actions that can be added as a stage or between stages to pause the pipeline and require explicit approval before proceeding. By placing the manual approval action between the Staging and Production stages, the pipeline will halt after the Staging stage completes and wait for an approver to manually approve the transition to the Production stage, ensuring no automatic deployment to production occurs without human oversight.

Answer

Add a manual approval action in the Staging stage

Answer

Configure the Production stage to use a CloudFormation change set with execution role

Answer

Use an SNS topic to notify developers of the deployment

Question 12

A company runs a web application on AWS Elastic Beanstalk. The application currently runs in a single environment. The developer wants to deploy a new version with zero downtime and be able to test the new version thoroughly before it receives any production traffic. Which deployment strategy should the developer use?

Accepted Answer

Create a new environment (green) with the new version, run tests against it, and then swap the environment URLs so that production points to the green environment.. Option C is correct because it describes a blue/green deployment strategy, which creates a separate 'green' environment with the new application version, allowing thorough testing before swapping the environment URLs (CNAME records) in Elastic Beanstalk. This ensures zero downtime because the swap is instantaneous and the original 'blue' environment remains untouched until the swap occurs.

Answer

Perform a rolling deployment with a batch size of one instance at a time.

Answer

Use an immutable deployment to launch a new set of instances and then swap the Auto Scaling group.

Answer

Use a rolling deployment with additional batch to launch new instances before terminating old ones.

Question 13

A company uses AWS CodePipeline with a manual approval step before deployment. The developer wants to ensure that if a pipeline execution is waiting for approval and new code is pushed, the awaiting execution is canceled and a new one starts with the latest code. Which pipeline execution mode should be configured?

Accepted Answer

Superseded. The Superseded execution mode is correct because it automatically cancels any currently running or waiting pipeline execution when a new one is triggered, ensuring that only the latest code proceeds through the pipeline. This is ideal for scenarios with manual approval steps where stale executions should not block or delay the deployment of the most recent commit.

Answer

Queued

Answer

Parallel

Answer

Single

Question 14

A company uses AWS Elastic Beanstalk to deploy a web application. The development team wants to test a new feature by routing a small percentage of traffic to a separate environment before fully rolling out. Which Elastic Beanstalk deployment strategy should the developer use?

Accepted Answer

Blue/green deployment. Blue/green deployment is the correct strategy because it allows you to route a small percentage of traffic to a separate environment (the 'green' environment) by swapping the CNAME record or using Elastic Beanstalk's environment URL swap feature. This enables testing the new feature with a subset of users before fully rolling out to the 'blue' environment, minimizing risk and enabling quick rollback if issues arise.

Answer

Rolling deployment

Answer

Immutable deployment

Answer

All at once deployment

Question 15

A company uses AWS Elastic Beanstalk to deploy a web application. The application requires a database connection string that is different for each environment (development, staging, production). The developer wants to set these values without hardcoding them in the application code. Which configuration method should the developer use?

Accepted Answer

Use environment properties in the Elastic Beanstalk console. Option B is correct because Elastic Beanstalk environment properties allow you to inject configuration values (like database connection strings) into your application at deployment time without hardcoding them. These properties are set per environment in the Elastic Beanstalk console or via CLI, and the application retrieves them as environment variables, making them environment-specific and secure.

Answer

Use the .ebextensions configuration files with environment-specific snippet files

Answer

Use Amazon RDS within Elastic Beanstalk

Answer

Use AWS Systems Manager Parameter Store with an IAM instance profile

Question 16

A developer is deploying a containerized application to Amazon ECS with the Fargate launch type using AWS CodeDeploy for blue/green deployments. The application is behind an Application Load Balancer (ALB). What is the minimum number of ALB target groups required for a blue/green deployment?

Accepted Answer

2. In a blue/green deployment with Amazon ECS (Fargate) and AWS CodeDeploy, the deployment process requires two distinct target groups: 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 during the deployment, allowing for instant rollback by switching back. A single target group cannot differentiate between the two environments, and three or more are unnecessary because the blue/green model only needs two active target groups at any time.

Answer

1

Answer

3

Answer

4

Question 17

A developer is deploying a serverless application using AWS SAM. The application includes an AWS Lambda function that is triggered by an S3 bucket event when an object is created. The developer wants to ensure that the Lambda function has the correct permissions to be invoked by S3. Which resource should the developer define in the SAM template?

Accepted Answer

AWS::Lambda::Permission. AWS::Lambda::Permission is the correct resource because it explicitly grants the S3 service principal permission to invoke the Lambda function when an object is created. In AWS SAM, this resource is automatically generated when you define an S3 event source on a Lambda function, but if you need to declare it manually or override permissions, you use AWS::Lambda::Permission with a SourceArn pointing to the S3 bucket and a SourceAccount to prevent confused deputy attacks.

Answer

AWS::S3::BucketPolicy

Answer

AWS::Lambda::EventSourceMapping

Answer

AWS::IAM::Role

Question 18

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 19

A developer is deploying a new version of a web application on AWS Elastic Beanstalk. The application currently runs in a single environment with an Auto Scaling group. The developer wants to ensure zero downtime during the deployment and that the new version can be fully tested before receiving any traffic. Which Elastic Beanstalk deployment policy should the developer use?

Accepted Answer

Immutable. Immutable deployment is the correct choice because it launches a completely new Auto Scaling group with the new application version, fully tests it before shifting any traffic, and then swaps the environment's instances in a single atomic action, ensuring zero downtime. This policy meets the requirement for full testing of the new version before it receives traffic, as traffic is only routed to the new instances after they pass health checks.

Answer

All at once

Answer

Rolling

Answer

Rolling with additional batch

Question 20

A developer is using AWS CloudFormation to deploy a stack with multiple resources. To ensure that a specific EC2 instance is created only after a security group is created, the developer wants to define the dependency. How should the developer achieve this in the CloudFormation template?

Accepted Answer

Use the DependsOn attribute on the EC2 instance resource. Option A is correct because the `DependsOn` attribute explicitly tells AWS CloudFormation to create the EC2 instance only after the security group has been successfully created. Without this explicit dependency, CloudFormation may attempt to create resources in parallel, which could cause the EC2 instance launch to fail if it references a security group that does not yet exist.

Answer

Use the Ref function to refer to the security group in the EC2 instance properties

Answer

Use the AWS::NoValue intrinsic function

Answer

Use the Condition attribute on the EC2 instance