Question #805
A company uses AWS Elastic Beanstalk to deploy a high-availability application. They want to update their application with minimal downtime and ensure that the new version is fully tested before shifting traffic. Which deployment strategies allow them to launch new instances for the update without affecting the existing environment until the new instances are verified? (Choose two.)
All at once
Immutable
Rolling
Blue/green
Rolling with additional batch
Explanation
The question requires deployment strategies that launch new instances without affecting the existing environment until verification.
- B. Immutable: Creates a new set of instances in a separate Auto Scaling Group (ASG). The existing environment remains operational until the new instances pass health checks, ensuring zero impact until verification.
- D. Blue/green: Deploys the update to a new environment (Green) while the original (Blue) stays active. Traffic shifts only after testing, minimizing downtime.
Other options:
- A. All at once: Replaces all instances simultaneously, causing downtime.
- C. Rolling: Replaces instances in batches, risking partial downtime and affecting the environment before full verification.
- E. Rolling with additional batch: Adds new instances but modifies the existing environment's capacity, which may not fully isolate the old version during testing.
Key Points:
1. Immutable and Blue/green strategies ensure isolation of the new version until verified.
2. Both strategies avoid modifying the existing environment until traffic is shifted post-testing.
Answer
The correct answer is: BD