DVA-C02 Question 215
Single answerYou are working on deploying a new version of your application hosted on AWS Elastic Beanstalk. Your team requires a deployment strategy that ensures there is no downtime during the deployment process, and the application can handle production traffic seamlessly during the update. Which deployment policy should you choose?
- A
All at once
- B
Rolling
- C
Rolling with additional batch
- D
Immutable
Show answer and explanation
Correct answer: D
Explanation
The 'Immutable' deployment policy is the most suitable for this scenario as it ensures that the new version of the application is deployed on a separate set of instances before cutting over traffic. This eliminates any downtime and minimizes the risk of errors affecting production traffic. Other policies like 'All at once', 'Rolling', and 'Rolling with additional batch' either involve downtime or risk inconsistent application behavior during deployment, which does not meet the given requirements.
- A. Incorrect.
The 'All at once' deployment policy replaces all instances of the application at the same time, leading to downtime during the deployment process. This does not meet the requirement of ensuring no downtime.
- B. Incorrect.
The 'Rolling' deployment policy updates instances in batches. While it minimizes downtime, it can still cause application disruptions if an error occurs, as some instances may be serving the old version while others serve the new version.
- C. Incorrect.
The 'Rolling with additional batch' deployment policy adds a new batch of instances temporarily during the deployment process to maintain capacity. However, it still involves replacing instances incrementally, which could lead to traffic inconsistencies.
- D. Correct.
The 'Immutable' deployment policy creates a new set of instances with the updated version before switching traffic to them. This ensures zero downtime and avoids any risk of inconsistent behavior, making it the best choice for seamless production traffic handling.