DOP-C02 Incident and Event Response Practice Question

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✓

  Create application -> Create deployment group with blue/green settings -> Deploy -> Validate deployment -> Reroute traffic

  Why this is correct

  The correct blue/green sequence in AWS CodeDeploy begins by creating the application, which is a prerequisite container for all deployment components. You then create a deployment group with blue/green settings, where you define the original (blue) fleet, replacement (green) fleet, and traffic rerouting behavior—such as manual or automatic reroute and optional hook actions. Only after the deployment group exists can you create a deployment to install the revision on the green fleet, run validation checks against that fleet, and then reroute traffic from blue to green. Deferring validation until after deployment ensures you never shift user traffic to an unverified environment, which is the core safety guarantee of blue/green deployments.

• ✗

  Create application -> Deploy -> Create deployment group -> Validate -> Reroute traffic

  Why it's wrong here

  This sequence incorrectly attempts to create a deployment before the deployment group exists. In AWS CodeDeploy, a deployment group is the target environment that defines the blue/green fleet configuration, service role, and deployment settings; without it, the CodeDeploy API has no context for where or how to deploy the application. Even the order of Validate and Reroute traffic is secondary here—the fatal flaw is that Deploy is impossible before Create deployment group, so this step order would fail immediately with a request to an undefined resource group.

• ✗

  Create deployment group -> Create application -> Deploy -> Validate -> Reroute traffic

  Why it's wrong here

  This order fails because a deployment group is an application-scoped resource; you cannot create or associate a deployment group before its parent application exists. The application acts as the logical container for the lifecycle, revision, and environment, so AWS CodeDeploy requires it to be created first. Attempting to create a deployment group first would result in an InvalidApplicationName error, since the application namespace simply doesn't exist to bind the group to, making the entire pipeline unstartable.

• ✗

  Create application -> Create deployment group -> Configure blue/green settings -> Validate -> Deploy -> Reroute traffic

  Why it's wrong here

  This sequence contains two fatal ordering errors: it runs Validate before Deploy, and it splits out Configure blue/green settings as a standalone step after deployment group creation. Validation can only occur after a deployment has provisioned and configured the green fleet—validating an empty or non-existent environment is meaningless and would pass falsely. Additionally, blue/green settings (e.g., traffic reroute approach, fleet sizing) are part of the deployment group's configuration, not a separate post-creation action, so reordering them breaks the deployment group definition and could cause a redeployment to inadvertently overwrite your intended settings.

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