DVA-C02 Deployment 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.

• ✗

  The EC2 instances have insufficient storage for the deployment.

  Why it's wrong here

  If EC2 instances have insufficient storage during deployment, the Elastic Beanstalk agent or deployment process would fail to write application files, logs, or dependencies to disk. This typically results in deployment failures, rollback events, or specific disk space errors visible in instance logs, rather than the application failing to start and the proxy returning a 502 Bad Gateway. A 502 error usually indicates a problem with the application server not responding to the proxy.

• ✓

  The application's requirements.txt file is missing a required dependency.

  Why this is correct

  When a Python application deployed on Elastic Beanstalk has a missing dependency in its `requirements.txt` file, the application server (e.g., Gunicorn, uWSGI) will fail to start correctly or crash immediately upon startup. The proxy server (e.g., Nginx, Apache) on the EC2 instance will then be unable to establish a connection or forward requests to the unresponsive application server. This common scenario directly leads to a 502 Bad Gateway error, as the proxy cannot communicate with the upstream application process.

• ✗

  The load balancer's health check path is incorrectly configured.

  Why it's wrong here

  An incorrectly configured load balancer health check path would cause the load balancer to repeatedly fail its health checks against the EC2 instance. Consequently, the load balancer would mark the instance as unhealthy and stop routing traffic to it, potentially leading to a degraded environment or instances being terminated and replaced. However, this configuration issue itself would not directly cause a 502 Bad Gateway error from the application server; rather, it would prevent traffic from reaching the instance in the first place, or cause the instance to be removed from service.

• ✗

  The RDS database connection string is incorrect.

  Why it's wrong here

  If the RDS database connection string is incorrect, the Python web application would typically start successfully but encounter errors when attempting to interact with the database. These errors would manifest as application-level exceptions (e.g., 500 Internal Server Error) within the application's logic, or specific error messages displayed to the user, rather than a 502 Bad Gateway. A 502 indicates that the web server (proxy) cannot communicate with the application server, not an issue within the application's business logic after it has successfully started.