Overview
Named after the 'canary in a coal mine,' this strategy involves deploying the new version to a small percentage of servers or users. If the 'canaries' show no issues (e.g., increased error rates or latency), the rollout continues to the rest of the infrastructure.
Key Concepts
- Subset Routing: Using a load balancer to direct a small percentage of traffic to the new version.
- Automated Analysis: Monitoring tools that compare metrics between the canary and the stable version.
- Rollback: Automatically reverting the canary if predefined thresholds are exceeded.
Benefits
- Early Warning: Detect critical bugs before they affect the entire user base.
- Reduced Blast Radius: Limit the impact of a failed deployment.
- Real-world Validation: Test the new version in the actual production environment.