DevOps
What is Canary Deployment?
Gradually shifting a small percentage of traffic to a new release, watching metrics before rolling it out to everyone.
Definition
A canary deployment releases new code to a small slice of traffic — perhaps 1%, then 10%, then 50% — while the rest stays on the stable version. Error rates and latency for the canary cohort are compared against the baseline; regressions trigger an automatic rollback before most users ever see the bug. The name comes from canaries in coal mines. Service meshes like Istio, ingress controllers, and tools such as Argo Rollouts and Flagger automate the traffic shifting and metric analysis. Canaries trade rollout speed for dramatically reduced blast radius.