Practice · Canary releases
What is a canary release?
A canary release sends a new version to a small slice of real traffic first, running it beside the stable version. A controller compares their error rate and latency, and rolls back automatically if the new version is worse, so a bad deploy reaches only a fraction of users.
How to get started with Canary releases
- 1 Deploy the new version beside the stable one and send it a small slice of real traffic, such as 1 percent.
- 2 Compare the canary against the baseline on error rate and latency, not against fixed thresholds.
- 3 Roll back automatically when the canary is meaningfully worse.
- 4 Promote in steps, such as 1, 10, 50, and 100 percent, with a check at each step.
The common mistake
What is the most common mistake with Canary releases?
Running a canary with no automated comparison, so a human has to notice the regression in time. At 1 percent of traffic, they usually do not.
See it in action
Rollouts Resolved calmly
The Canary That Caught It
A bad deploy raised the error rate the instant it touched real traffic. The canary saw it at one percent, rolled itself back automatically, and 99 percent of users never noticed.