What does blue/green deployment allow when updating applications?

Blue/green deployment is a strategy that enables applications to be updated seamlessly without downtime by maintaining two separate environments, known as the "blue" environment and the "green" environment. When a new version of the application is ready, it is deployed to the inactive environment. After thorough testing, traffic is switched from the old version (the current active environment) to the new version.

This process ensures that users experience no interruptions, as they are directed to the new environment while the old one remains available if necessary. If any issues arise with the new deployment, switching back to the old version can be done quickly, allowing for immediate rollback if needed. However, the primary advantage that blue/green deployment offers is the ability to introduce updates without affecting the availability of the application, thus significantly enhancing the user experience.

This method is distinct from other strategies that may focus on load distribution or security enhancements but do not directly address the core capability of zero-downtime updates provided by blue/green deployment.