Final answer:
The main difference is that blue-green deployment uses two identical production environments to switch traffic between versions after full deployment, while canary deployment rolls out the new version to a subset of users first, gradually increasing the rollout if performance is satisfactory.
Step-by-step explanation:
The blue-green deployment and canary deployment are strategies used in software development and operations to manage the release of new versions of an application with minimal downtime and risk. Blue-green deployment involves maintaining two identical production environments, only one of which, at any given time, serves all the production traffic. For example, 'blue' is currently active and serving all user traffic while 'green' is idle. When a new version of the application is ready for release, it is deployed to the idle environment, which is thoroughly tested. Once ready, the traffic is switched to the 'green' environment. If any issues occur, traffic can be quickly switched back to 'blue'.
On the other hand, canary deployment is a pattern where the new version of an application is rolled out to a small subset of users before being made available to the entire user base. This can involve routing a percentage of traffic or specific user groups to the new version and monitoring performance and feedback carefully. If the new release performs well, it is gradually rolled out to the entire user base. This approach allows detecting any issues early in a controlled manner without affecting all users.