BlueGreenDeployment

BlueGreenDeployment, commonly called blue-green deployment, is a release management strategy in which two identical production environments are maintained. One environment serves live production traffic (blue) while the other (green) is idle and kept ready for activation. The switch between environments is performed through a load balancer, DNS change, or service mesh routing, allowing near-zero downtime during the transition.

In practice, teams keep two parallel production environments that are mirrored in configuration, code, and data stores. When a new version is ready, it is deployed to the idle green environment and undergoes automated testing, smoke tests, and any required QA. Once validated, traffic is redirected from blue to green. Monitoring takes place after the cutover, and if issues arise, traffic can be redirected back to blue, achieving a rapid rollback. After a successful switch, the previously live environment becomes the new idle environment and can be updated for the next release. For stateful applications, data management is critical; approaches include separate databases with careful migration planning or synchronized data replication, with attention to schema changes and potential data drift.

Benefits include near-zero downtime, rapid rollback, and the ability to test in a production-like setting with real traffic. It supports safer releases within CI/CD pipelines and can be combined with canary approaches and feature flags. Considerations involve doubled infrastructure costs, complexity of data synchronization, and the need for robust automation, monitoring, and rollback procedures. See also related deployment strategies such as canary deployments and feature flag management.