AZ-400 Question 159
Select 2Your DevOps team at an e-commerce company is preparing to release a new microservice that significantly changes the user account management process. The business wants to initially expose this new service to only a small subset of production users, observe performance and user feedback, and then gradually roll it out to the larger user base if everything goes smoothly. Additionally, they require the ability to quickly disable the new service if critical issues arise. Which two deployment strategies should you recommend to meet these requirements?
- A
Blue-Green Deployment
- B
A/B Testing
- C
Canary Releases
- D
Feature Flags
Show answer and explanation
Correct answers: C, D
Explanation
Canary releases, combined with feature flags, address both gradual exposure to a small user subset and rapid rollback if cracks in performance or stability appear. Canary deployments offer a measured rollout approach, while feature flags provide dynamic on/off functionality for rapid response. Together, they align with Microsoft DevOps best practices for progressive exposure and risk mitigation. For more information, consult Microsoft documentation on progressive exposure and feature flagging strategies at https://docs.microsoft.com/azure/devops/.
- A. Incorrect.
Blue-Green Deployment: Incorrect. While this strategy provides zero-downtime swaps by maintaining two identical environments (blue and green), it does not provide a mechanism to gradually expose features to a small subset of users for feedback. Instead, traffic typically switches all at once from blue to green (or vice versa).
- B. Incorrect.
A/B Testing: Incorrect. A/B testing is best suited for comparing two different experiences (e.g., layout changes) for metrics like click-through rates or user engagement. It doesn�t inherently control the exposure of new features to a small subset of production users for performance monitoring or quick rollback of the entire service.
- C. Correct.
Canary Releases: Correct. Canary releases allow you to deploy new features to a small subset of users first, analyze performance and feedback, then gradually increase the number of users. This matches the requirement for incremental rollout to a limited audience.
- D. Correct.
Feature Flags: Correct. Feature flags let you toggle the new service on or off for different user groups in real time. They enable quick deactivation of the feature if major issues are found, meeting the requirement for rapid rollback.