Blue/green deployment
A blue/green deployment runs the new version as a parallel environment, verifies it, then switches all traffic at once. Reverting is the same switch back.
What is blue/green deployment?
A blue/green deployment runs the new version as a parallel environment, verifies it, then switches all traffic at once. Reverting is the same switch back.
Plain and technical
You build a second copy of your environment with the new version, check it, then move everyone over in one step. If something is wrong, you move everyone back just as quickly.
Blue/green provides the fastest reversion of any strategy because the previous environment remains running and intact. Its costs are the doubled capacity during the overlap and the fact that shared stateful dependencies, especially databases, are not duplicated, so schema compatibility between versions remains a constraint.
What it looks like in practice
Nearby vocabulary
Canary deployment
A canary deployment releases a new version to a small share of production traffic first, increasing that share only if measured health stays within threshold.
Continuous delivery
Continuous delivery is the practice of keeping software in a state where any change that has passed verification could be released to production at any time.
How DevOpsArk handles blue/green deployment
More definitions
See these concepts in a running system
A 30-minute walkthrough against your own infrastructure rather than a slide about the theory.