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blue-green deploy
Two full environments. Traffic flips from old to new. Flip back if the new one is wrong.
What is blue-green deploy?
Blue-green keeps the old version running while the new version warms. A switch moves traffic. Rollback is switching back, which only works if the old version can still read the data. It costs two stacks. A canary is a slice, not a second stack.
Why does blue-green deploy matter when vibe coding?
Models say blue-green and then overwrite the only deployment. Name the two targets and the switch.
How do you do blue-green deploy?
Deploy green beside blue. Smoke-test green. Switch. Keep blue until green is trusted. Schema must be readable by both while both exist.
How do you ask a model for blue-green deploy?
Blue-green (service). Deploy the new color beside the old. Do not delete the old until the switch is verified. Rollback is switching back. Database changes must work with both versions during the overlap.
What goes wrong with blue-green deploy?
Green that migrates the database in a way blue cannot read. The flip back is now a data incident.