Canary Deployments Deep Dive#

A canary deployment sends a small percentage of traffic to a new version of your application while the majority continues hitting the stable version. You monitor the canary for errors, latency regressions, and business metric anomalies. If the canary is healthy, you gradually increase its traffic share until it handles 100%. If something is wrong, you roll back with minimal user impact.

Why Canary Over Rolling Update#

A standard Kubernetes rolling update replaces pods one by one until all pods run the new version. The problem is timing. By the time you notice a bug in your monitoring dashboards, the rolling update may have already replaced most or all pods. Every user is now hitting the broken version.