Answer: Traffic splitting by version

## Explanation For App Engine, the correct feature to direct a small percentage of traffic (like 1%) to a new version is **Traffic splitting by version**. This is a built-in App Engine feature that allows you to split traffic between different versions of your application. ### Why other options are incorrect: - **A) Canary deployment on GKE**: This is for Google Kubernetes Engine deployments, not App Engine. - **C) Separate test project**: While you could use a separate project for testing, this doesn't achieve the goal of having 1% of users see the new version in the same production environment. - **D) Cloud Run gradual rollout**: This is specific to Cloud Run services, not App Engine. ### How Traffic Splitting works in App Engine: 1. Deploy your new version to App Engine 2. Use the `gcloud app services set-traffic` command or the Cloud Console 3. Specify the traffic percentage for each version 4. For example: `gcloud app services set-traffic default --splits v2=0.01,v1=0.99` This allows you to gradually roll out new versions to a small percentage of users for testing before making it available to everyone.

Author: Rodrigo Sales