What It Is
Traffic shifts gradually from old instances to new ones while both run, so users see no error pages, dropped sessions, or maintenance windows. The goal is simple: users never notice that a release happened.
Key Points
- Rolling updates: replace instances a few at a time.
- Blue-green: switch between two full environments.
- Canary releases: send a small share of traffic to the new version first.
- Safeguards: health checks, backward-compatible database changes, and fast rollback.
Why It Matters
Without safeguards, a failed release can still cause an outage even with gentle deployment. It depends on health checks, load balancers, and backward-compatible database changes, so planning matters as much as the tooling.
How ClearLeaff Applies It
We deliver zero-downtime deployments through Kubernetes and GitOps pipelines, extend the principle to edge devices with zero-touch OTA updates, and add AI-assisted rollback prediction.