It’s a deployment strategy to create two separate, but identical deployment or production environments. One environment (blue) is running the current application version and one environment (green) is running the new application version. Once testing has been completed on the green environment, live application traffic is directed to the green environment and the blue environment is deprecated.
A blue-green deployment strategy increases application availability and reduces deployment risk by simplifying (only to the previous running version) the rollback process if a deployment fails.
Advantages:
- Increased application availability: With blue-green deployment, there is always a version of the application that is live and available to users.
-
Reduced deployment risk: By having identical environments, the deployment risk is reduced, and the rollback process is simplified in the event of a deployment failure.
Rollback to the previous version is simplified, however, rollback to an older or an earlier version is limited. Required full deployment.
Improved user experience: With continuous delivery and reduced downtime, users can enjoy a seamless experience with new features and updates.
Easy production testing: Testing can be done on the new environment (green) without affecting the live environment (blue).
Disadvantages:
- Cost & Complexity: Setting up and Maintaining two identical environments requires additional resources, and infrastructure requirements which have the potential to increase complexity and cost.
- Data consistency: Depending on the application, it may be challenging to ensure that data is consistent between the blue and green environments during the deployment process.
- Limited rollbacks: While blue-green deployment simplifies the rollback process, it can also limit the ability to roll back to an earlier version of the application if necessary.
Tips for minimizing the disadvantages
- Cloud-Based Deployment Platform and Containerization: The cloud is cost-effective. Also, automated testing and deployment processes reduce complexity.
- Use feature flags to test new features before deploying them to production. This can help to reduce the risk of problems with the new version.
- Well-defined or automated rollback plan
- Having a monitoring system ready to identify issues as soon as they occur
- Having a communication channel with end users
Push-and-Pray vs. Blue-Green Deployment
| Deployment strategy | Advantages | Disadvantages |
|---|---|---|
| Push-and-Pray Deployment | Simple, easy to implement | Risky, can lead to downtime, errors, and security vulnerabilities |
| Blue-green deployment | More reliable, less risky | More complex, more expensive to implement |
Top comments (0)