AWS DevOps Engineer Professional Practice Test

What approach ensures minimal downtime when deploying a new application version?

1. Blue/Green deployment

2. Canary deployment

3. Rolling update

4. Recreate deployment

The correct answer is: Blue/Green deployment

The blue/green deployment approach is designed to ensure minimal downtime when deploying a new application version by maintaining two separate environments, typically referred to as "blue" and "green." One environment is actively serving production traffic while the other is on standby. When it's time to deploy a new version of the application, it is first deployed to the idle environment (for example, the green environment) without impacting the current user experience in the active environment (the blue environment). Once the new version is fully deployed and tested in the idle environment, the traffic is switched from the active environment to the newly updated environment. This transition is seamless, meaning users experience little to no downtime during the deployment process. If any issues arise after the switch, it is straightforward to revert back to the previous version by simply routing traffic back to the previous environment. This approach contrasts with other deployment strategies like canary deployments, which involve gradually rolling out an update to a small segment of users before a full deployment, or rolling updates, which progressively replace instances in a live application with the new version. Both of these can result in a longer potential exposure to issues before full rollback can be achieved compared to the immediate switch enabled by blue/green deployments. Recreate deployment involves shutting down the existing