AWS DVA-C02 Drill: CodeDeploy Lifecycle Hooks - Understanding In-Place Deployment Order

Jeff’s Note

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Unlike generic exam dumps, ADH analyzes this scenario through the lens of a Real-World Lead Developer.

For AWS DVA-C02 candidates, the confusion often lies in the precise ordering of lifecycle event hooks in an in-place deployment. In production, this is about knowing exactly when your application stops and when deployment scripts execute to create a reliable CI/CD pipeline. Let’s drill down.

The Certification Drill (Simulated Question)

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Scenario

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Windward Apps is developing an internal deployment pipeline using AWS CodeDeploy for their fleet of EC2 instances. They want to automate the lifecycle events during an in-place deployment to ensure the application stops gracefully, new files install correctly, and the service restarts without downtime.

The Requirement:

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What is the correct ordering of lifecycle event hooks that AWS CodeDeploy follows during an in-place deployment?

The Options

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• A) BeforeInstall -> ApplicationStop -> ApplicationStart -> AfterInstall
• B) ApplicationStop -> BeforeInstall -> AfterInstall -> ApplicationStart
• C) BeforeInstall -> ApplicationStop -> ValidateService -> ApplicationStart
• D) ApplicationStop -> BeforeInstall -> ValidateService -> ApplicationStart

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leave a comment:

Correct Answer

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B) ApplicationStop -> BeforeInstall -> AfterInstall -> ApplicationStart

Quick Insight: The Developer Imperative

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The precise sequence ensures your application is stopped before the new version files are installed (BeforeInstall), followed by verifying the installation (AfterInstall) and finally restarting the application (ApplicationStart). Getting this sequence wrong risks corrupted deployments or service downtime.

Content Locked: The Expert Analysis

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You’ve identified the answer. But do you know the implementation details that separate a Junior from a Senior?

The Expert’s Analysis

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Correct Answer

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Option B

The Winning Logic

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AWS CodeDeploy lifecycle hooks for in-place deployments follow this exact sequence:

1. ApplicationStop – Here, any running instance of your application must stop gracefully to avoid conflicts during the update. This gives a chance to close open connections or run cleanup logic.
2. BeforeInstall – Prepares the deployment, often used to back up files or install dependencies before the new revision files are copied over.
3. AfterInstall – Runs after new content is installed; perfect for configuration changes or permission fixes on updated files.
4. ApplicationStart – Finally, the application service restarts, picking up the new code or configuration.

This ordering enables smooth hot updates without unexpected downtime, a critical aspect of DevOps pipelines.

The Trap (Distractor Analysis):

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• Why not A? Because ApplicationStop must happen before BeforeInstall. In option A, BeforeInstall runs first, which violates the logic of stopping the app before installation.
• Why not C or D? The ValidateService hook only exists as part of Blue/Green deployments, not for in-place deployments. Including it here is a common distractor.
• Why not D? Same reasoning as C, plus the sequence places ValidateService in an invalid order.

The Technical Blueprint

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# Example CLI command to start a CodeDeploy deployment for an existing application and deployment group
aws deploy create-deployment --application-name WindwardApp \
  --deployment-group-name ProdGroup \
  --deployment-config-name CodeDeployDefault.AllAtOnce \
  --s3-location bucket=mybucket,key=app.zip,bundleType=zip

The Comparative Analysis

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Real-World Application (Practitioner Insight)

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Exam Rule

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“For the exam, always pick ApplicationStop first when you see AWS CodeDeploy in-place deployment lifecycle hooks.”

Real World

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“In real production deployments, teams often customize BeforeInstall and AfterInstall hooks with detailed shell or PowerShell scripts, ensuring graceful service shutdown, resource backup, and validation logic.”

(CTA) Stop Guessing, Start Mastering

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Disclaimer

This is a study note based on simulated scenarios for the AWS DVA-C02 exam.