Simple definition
Canary deployment progressively exposes a release to a subset of users so its behavior can be observed before wider rollout.
Purpose and use
A canary deployment exposes a new version to a controlled portion of usage before wider rollout.
How does it work?
Routing, instances or other mechanisms select affected users. Measurements guide continuation, stopping or rollback.
Example and verification
Define monitored indicators, observation duration and decision thresholds before starting with representative traffic.
Points to watch
Low volume can hide rare errors or particular user groups. Absence of alerts alone does not demonstrate functional success.
In short
A canary limits initial exposure when sampling, measurement and rollback mechanisms are suitable.