What is canary release?
A canary release rolls a change out to a small share of users first, watching for problems before releasing to everyone.
Named after canaries used to detect gas in mines, the approach limits the blast radius of a bad release. If error rates or key metrics worsen, the change is rolled back before most users see it.
It complements pre-release testing rather than replacing it. Testing catches known risks before release, and canaries catch what testing missed under real traffic.
Example
A new search service receives 5% of traffic. Synthetic checks and error monitoring stay healthy for an hour, so traffic is increased to 50% and then 100%.
Best practices
- Define the metrics that trigger rollback
- Start with a small, representative slice
- Run synthetic checks against the canary
- Automate rollback where possible
Ship without fear.
Start testing free in minutes, or let a QAShift engineer deliver your first morning report within 5 days.