Blue-Green Deployment
Blue-green deployment maintains two identical environments (blue/green); the new version deploys to the idle environment, then traffic switches over, achieving zero downtime.
Purpose
Zero-downtime deployment with fast rollback, suited to critical services.
Mechanism
The blue environment runs the current version and serves traffic while green receives the new release. After validating green, routing (LB/Ingress) switches to it. On failure, switch back to blue. Requires double the resources. Database migrations must stay compatible with both versions.
Use cases
- Zero-downtime deployment
- Fast rollback
- Release strategy