SOA-C02 Deployment, Provisioning, and Automation — 10 Questions

Question 1

A team uses AWS CodeDeploy with a deployment configuration of CodeDeployDefault.OneAtATime to deploy a web application to an Auto Scaling group. Instances are behind an Application Load Balancer. The deployment fails with 'The overall deployment failed because too many individual instances failed deployment.' What is the most likely cause?

Accepted Answer

The health check grace period on the Auto Scaling group is too short.. The deployment fails because the health check grace period on the Auto Scaling group is too short. When CodeDeploy deploys one instance at a time (CodeDeployDefault.OneAtATime), the instance is taken out of service, updated, and then returned to the load balancer. If the grace period expires before the instance passes its health checks, the Auto Scaling group marks it as unhealthy and terminates it, causing the deployment to fail with 'too many individual instances failed.'

Answer

The target group deregistration delay is too long.

Answer

The CodeDeploy agent is not installed on the instances.

Answer

The deployment group is configured to skip the ELB health check.

Question 2

A development team uses AWS CloudFormation to deploy infrastructure. They want to update a stack but first need to review how the changes will impact existing resources before applying them. Which CloudFormation feature should they use?

Accepted Answer

Change sets. Change sets allow you to preview how proposed changes to a CloudFormation stack will affect your running resources before you apply them. They generate a summary of the changes (additions, modifications, deletions) based on the new template and parameters, enabling you to assess impact such as resource replacement or updates without executing the changes. This directly addresses the team's requirement to review changes before applying them.

Answer

Stack policies

Answer

Condition functions

Answer

Custom resources

Question 3

A company uses AWS CodeDeploy to deploy a new version of an application to EC2 instances in an Auto Scaling group behind an Application Load Balancer. The company requires zero downtime during the deployment. Which deployment configuration should be used?

Accepted Answer

Create a blue/green deployment by configuring CodeDeploy to launch new instances and shift traffic after validation.. Option D is correct because a blue/green deployment with CodeDeploy, where new instances are launched and traffic is shifted only after validation, ensures zero downtime by keeping the old environment (blue) fully serving traffic until the new environment (green) is verified healthy. This approach avoids any in-place updates that could temporarily reduce capacity or cause service disruption, meeting the requirement for zero downtime during deployment.

Answer

CodeDeployDefault.AllAtOnce

Answer

CodeDeployDefault.OneAtATime

Answer

CodeDeployDefault.EC2/OnPremises: BlueGreenDeployment

Question 4

A company uses AWS CloudFormation to deploy a three-tier web application. The SysOps administrator wants to update a critical parameter, such as the instance type, and ensure that the change is applied without recreating the EC2 instance, if possible. Which CloudFormation stack update feature should be used to achieve this?

Accepted Answer

Change sets. Change sets allow you to preview the changes that will be made to your stack resources before executing them. For an update that modifies an instance type, CloudFormation will attempt to perform an update without replacement if the resource supports it (e.g., AWS::EC2::Instance supports in-place updates for the InstanceType property). By using a change set, you can confirm that the update will not recreate the EC2 instance before applying it.

Answer

Stack policy

Answer

Update with drift detection

Answer

Directly edit the stack template and use the update stack action

Question 5

A company uses AWS CodeDeploy to deploy an application to an Auto Scaling group. The deployment strategy is set to CodeDeployDefault.HalfAtATime. The lifecycle hooks for the Auto Scaling group include a test hook that runs during instance launch. During a recent deployment, the deployment failed because the new instances failed the test hook and were not marked as healthy. The SysOps administrator needs to ensure that failed instances are automatically terminated and replaced with new ones from the Auto Scaling group. Which configuration change should the administrator make?

Accepted Answer

Modify the Auto Scaling group's health check type to ELB. Option A is correct because setting the Auto Scaling group's health check type to ELB (Elastic Load Balancer) ensures that the Auto Scaling group uses the ELB's health check status to determine instance health. When the test lifecycle hook fails, the new instances are not marked as healthy by the ELB, causing the Auto Scaling group to automatically terminate and replace them. This aligns with the requirement to automatically replace failed instances, as the default EC2 health check only considers instance status (e.g., running vs. stopped) and does not reflect application-level health.

Answer

Modify the CodeDeploy deployment configuration to use an increased minimum healthy instance count

Answer

Modify the Auto Scaling group's health check grace period to a lower value

Answer

Modify the CodeDeploy deployment to ignore the lifecycle hook failure

Question 6

A company uses AWS CloudFormation to deploy a web application. The template currently hard-codes the EC2 instance type (e.g., t3.medium). The SysOps administrator wants to make the instance type configurable so that different environments (dev, test, prod) can use different instance types without modifying the template each time. Which CloudFormation feature enables this?

Accepted Answer

Parameters. Option A is correct because CloudFormation Parameters allow you to pass custom values into a template at stack creation or update time. By defining a parameter for the instance type (e.g., with allowed values like t3.micro, t3.medium, t3.large), you can reuse the same template across dev, test, and prod environments without editing the template file itself.

Answer

Mappings

Answer

Conditions

Answer

Outputs

Question 7

A SysOps administrator uses AWS CodeDeploy to deploy a new version of an application to an Auto Scaling group. The deployment uses the 'CodeDeployDefault.OneAtATime' deployment configuration. During the deployment, the first instance succeeds, but subsequent instances fail because the new application version has a bug that causes the application health check to fail. The administrator wants to immediately roll back the change and restore the previous working version on all instances. Which action should the administrator take?

Accepted Answer

Initiate a rollback from the CodeDeploy console to redeploy the previous working revision.. Option A is correct because CodeDeploy supports automatic and manual rollbacks to a previous working revision. When a deployment fails, the administrator can initiate a rollback from the CodeDeploy console, which redeploys the last successful revision to all instances in the deployment group, including those that were already updated. This ensures the previous working version is restored across the entire Auto Scaling group.

Answer

Stop the deployment immediately; the instances that have already been updated will revert automatically.

Answer

Edit the deployment group settings to pause deployments after a failure, then manually fix the instances.

Answer

Redeploy the same failing revision but with a different deployment configuration.

Question 8

A company uses AWS CodePipeline to automate the deployment of a web application. The pipeline consists of a source stage (AWS CodeCommit) and a deploy stage (AWS CodeDeploy) that deploys to an Auto Scaling group. The SysOps administrator needs to add a stage to run automated unit tests before the deployment proceeds. The tests must be executed in an isolated environment, and if they fail, the pipeline must stop and notify the development team. Which action should the administrator take?

Accepted Answer

Add a stage between source and deploy that uses an AWS CodeBuild action to run unit tests defined in a buildspec file. The pipeline will automatically stop if the build action fails.. Option C is correct because AWS CodeBuild is natively integrated with CodePipeline to run automated tests defined in a buildspec file. When the build action fails, CodePipeline automatically stops the pipeline execution and can send notifications via Amazon SNS, meeting the requirement for an isolated test environment and automatic failure notification without manual intervention.

Answer

Add a manual approval action between the source and deploy stages. The development team will manually run the tests on their local machines and then approve the pipeline to proceed.

Answer

Insert a test stage after the source stage with an AWS CloudFormation action that deploys a test stack and runs tests using a custom resource Lambda function.

Answer

Add a Lambda function as an action in the pipeline that runs the unit tests. The Lambda function writes the test results to an S3 bucket, and a subsequent approval action checks the results.

Question 9

A SysOps administrator uses AWS CloudFormation to manage a stack that includes an Amazon EC2 instance. The administrator wants to update the instance type from t3.medium to t3.large without recreating the instance. The instance type change is supported as a simple update in CloudFormation. Which stack update method should the administrator use to apply this change with the least disruption?

Accepted Answer

Directly update the stack by modifying the template and submitting the update via the AWS Management Console, AWS CLI, or API.. Option A is correct because changing an EC2 instance type from t3.medium to t3.large is a supported simple update in CloudFormation, meaning the resource can be updated in-place without replacement. By directly updating the stack via the AWS Management Console, AWS CLI, or API, the administrator applies the change immediately with minimal disruption, as CloudFormation will stop the instance, modify the instance type, and restart it. This method avoids the overhead of creating a change set or deleting and recreating the stack, which would cause unnecessary downtime or complexity.

Answer

Create a change set to review the changes, then execute the change set.

Answer

Apply a stack policy to the EC2 instance to allow the update, then update the stack.

Answer

Delete the existing stack and create a new stack with the updated instance type.

Question 10

A company uses AWS Systems Manager Patch Manager to automate patching of Amazon EC2 instances. The SysOps administrator needs to configure a maintenance window that will patch instances on the second Tuesday of every month at 2:00 AM. The administrator wants to ensure that patches are automatically applied but reboots are only performed if required. Which combination of configurations should the administrator use?

Accepted Answer

Create a maintenance window with a cron schedule of cron(0 2 ? * TUE#2 *) and use an AWS-RunPatchBaseline document with operation 'Install' and reboot option 'RebootIfNeeded'.. Option A is correct because it uses the cron expression `cron(0 2 ? * TUE#2 *)` to schedule the maintenance window for the second Tuesday of every month at 2:00 AM, and the `AWS-RunPatchBaseline` document with operation `Install` and reboot option `RebootIfNeeded` ensures patches are applied automatically and reboots only occur when required by the patch installation.

Answer

Create a maintenance window with a rate schedule of 30 days and use an AWS-ApplyPatchBaseline document with operation 'Scan' and reboot option 'RebootIfNeeded'.

Answer

Create a maintenance window with a cron schedule of cron(0 2 14 * ? *) and use an AWS-RunPatchBaseline document with operation 'Install' and reboot option 'RebootIfNeeded'.

Answer

Create a maintenance window with a cron schedule of cron(0 2 2 * 2 *) and use an AWS-InstallPatchBaseline document with operation 'Install' and reboot option 'NoReboot'.