Blue-Green Deployment is a software release management strategy that reduces downtime and risk by maintaining two identical production environments, referred to as blue and green. In this approach, one environment (blue) handles live traffic while the other (green) remains idle. The blue environment represents the currently active version of the software, while the green environment is a completely new version ready for deployment.
The blue-green deployment process involves the following steps:
- Initially, the blue environment is live and handling user requests.
- When a new version of the software is ready for deployment, it is deployed to the green environment.
- After the green environment is up and running, a process called the switchover is performed, shifting the live traffic from the blue environment to the green environment.
- If any issues or bugs arise in the green environment, the switchover can be easily reversed to revert back to the stable blue environment.
- Once the green environment is stable and free of issues, it becomes the new blue environment for future deployments.
The blue-green deployment strategy enables seamless releases with minimal disruption to users. By maintaining duplicate environments, it provides a safety net for rolling back changes if problems occur in the new version. Additionally, it allows for easy testing and validation of the green environment before making it live.