Overview
In a Blue-Green deployment, one environment (Blue) runs the current production version, while the other (Green) runs the new version. Once the Green environment is fully tested and ready, traffic is switched from Blue to Green, typically using a load balancer or DNS change.
Key Benefits
- Zero Downtime: The switch happens almost instantaneously.
- Instant Rollback: If an issue is detected in the Green environment, traffic can be switched back to Blue immediately.
- Reduced Risk: Testing happens in a production-identical environment before users see the changes.
Considerations
- Cost: Requires doubling the production infrastructure during the deployment process.
- Data Consistency: Databases must be handled carefully to ensure data is not lost or corrupted during the switch.