DVA-C02 Deployment Practice Question
A developer is using AWS CodeDeploy to deploy an application to an EC2 instance. The deployment fails with the error 'The overall deployment failed because the deployment group did not have enough instances to successfully deploy.' What is the most likely cause?
⚠ Common exam trap
DVA-C02 often tests whether candidates can distinguish between deployment-group-level failures (no instances, wrong tags) and instance-level failures (agent down, bad appspec), so the trap is picking an instance-specific cause for a group-level error message.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The deployment group contains zero instances.
The error message 'the deployment group did not have enough instances to successfully deploy' is CodeDeploy's way of saying it could not find any healthy target instances matching the deployment group's criteria. When a deployment group contains zero registered EC2 instances (or none matching the tag/ASG filters), CodeDeploy has nothing to deploy to and fails immediately with this exact error. The fix is to verify the deployment group's tag filters or Auto Scaling group association and ensure at least one instance is registered and healthy.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
The revision has an incorrect file format.
Why it's wrong here
CodeDeploy expects application revisions to be packaged in specific, supported formats like .zip or .tar.gz. If the uploaded revision file is corrupted, malformed, or uses an unsupported compression format, CodeDeploy's initial validation process will fail to extract or interpret the package. This fundamental packaging error prevents the deployment from even starting, resulting in a "Failed" status before any instance-specific actions can be attempted.
- ✓
The deployment group contains zero instances.
Why this is correct
A CodeDeploy deployment group defines the set of target instances (EC2, on-premises, or ECS tasks) where the application revision will be deployed. If a deployment group is configured to contain zero instances, CodeDeploy has no valid compute resources to send the application to. Consequently, the deployment cannot proceed and will immediately fail, as there are no targets available to execute the deployment steps, leading to a "Failed" deployment status from the outset.
- ✗
The CodeDeploy agent on the instance is not running.
Why it's wrong here
The CodeDeploy agent is a critical component that runs on each target instance, responsible for receiving commands from the CodeDeploy service and executing deployment scripts. If the agent is not running on a particular instance, that specific instance will fail its deployment steps, often timing out or reporting an agent communication error. However, this is an instance-level failure; other instances in the same deployment group with a healthy, running agent would continue their deployments, potentially leading to a partial success or an instance-specific failure, not a complete deployment group failure.
- ✗
The appspec file contains an invalid lifecycle hook.
Why it's wrong here
The `appspec.yml` file dictates the deployment's lifecycle hooks and the scripts to be executed during each phase. If the `appspec.yml` contains an invalid lifecycle hook (e.g., a misspelled hook name, a reference to a non-existent script, or incorrect script permissions), CodeDeploy will attempt to execute it during the relevant deployment phase on the target instance. This will cause a script execution failure on that specific instance, halting the deployment at that particular lifecycle event for that instance, rather than a pre-deployment validation error of the entire revision or deployment group.
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Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official Amazon Web Services exam blueprint
This DVA-C02 practice question is part of Courseiva's free Amazon Web Services certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the DVA-C02 exam.