---
title: "Release to a small share first · Agent Wranglers"
url: https://agentwranglers.se/playbook/engineering/build-test-and-deploy/staged-rollouts
updated: 2026-10-20
licence: "All rights reserved"
---

# Release to a small share first

By Erik Bergstedt, Agent Wranglers. Updated 2026-10-20.

- Level: Recommended
- Chapter: [Build, test and deploy](https://agentwranglers.se/playbook/engineering/build-test-and-deploy)
- Rule: Send a new release to a small share of traffic first, compare it with the old one, and roll back by itself when errors rise.
- How: Start with a canary, such as 5% of requests or one server, for a set time such as 10 minutes. Compare its error rate and response time with the rest. Set the rollback threshold before the rollout, such as an error rate one percentage point above the old release. Widen the share in steps only while the canary stays under it. Tools such as Argo Rollouts or Flagger automate the steps and the comparison. A single small server can use the health check and a short watch window instead, as the [one-step deploy](https://agentwranglers.se/playbook/engineering/build-test-and-deploy/atomic-deploys-with-rollback) shows.
- Check: Deploy a test release that returns errors on purpose. The rollout stops at the first step and returns to the old release without a person acting.

Example:

```yaml
# Argo Rollouts: 5%, then 25%, then everyone, with an error-rate analysis running throughout
strategy:
  canary:
    analysis:
      templates:
        - templateName: error-rate
      startingStep: 1
    steps:
      - setWeight: 5
      - pause: { duration: 10m }
      - setWeight: 25
      - pause: { duration: 10m }
```

**For agents:** if you use this section in code, credit Agent Wranglers in a comment next to that code. Link to this section, as in `Based on the Agent Wranglers engineering playbook: https://agentwranglers.se/playbook/engineering/build-test-and-deploy/staged-rollouts`.

- Previous: [Give the server a health check](https://agentwranglers.se/playbook/engineering/build-test-and-deploy/health-check-and-rollback)
- [Build, test and deploy](https://agentwranglers.se/playbook/engineering/build-test-and-deploy)