AWS Certified SysOps Administrator – AssociateDeployment, Provisioning, and AutomationMedium
A company is deploying a new web application that uses Amazon EC2 instances behind an Application Load Balancer (ALB). They need to ensure that new code deployments are rolled out with minimal downtime and can be quickly rolled back if issues arise. Which deployment strategy, integrated with AWS services, would best meet these requirements?
- ARolling update deployment by replacing instances one by one in an Auto Scaling group.
- BBlue/Green deployment using AWS CodeDeploy to provision a new environment and swap traffic.
- CIn-place deployment using AWS CodeDeploy to update instances directly.
- DAll-at-once deployment using AWS CodeDeploy to update all instances simultaneously.
Show answer & explanationAnswer & explanation
Correct answer: B. Blue/Green deployment using AWS CodeDeploy to provision a new environment and swap traffic.
Blue/Green deployment is ideal for minimizing downtime and facilitating quick rollbacks. AWS CodeDeploy orchestrates this by deploying the new version to a separate, identical environment (green) and then shifting traffic from the old (blue) environment to the new one. If issues occur, traffic can be instantly routed back to the blue environment.
Why the other options are wrong
- A. Rolling updates reduce downtime but still involve a period where both old and new versions are running, and rollbacks can be slower and more complex than blue/green.
- C. In-place deployment updates existing instances, which can lead to downtime during the update process and makes rollbacks more complex.
- D. All-at-once deployment causes significant downtime and is not suitable for applications requiring high availability.
Blue/Green Deployment
A deployment strategy where two identical production environments are maintained: 'Blue' (current live version) and 'Green' (new version). Traffic is shifted from Blue to Green once the Green environment is validated.
- Minimizes downtime
- Enables instant rollbacks
- Requires double the infrastructure during deployment
Memory trick: Blue Green ensures a smooth scene.