# Canary Deployment

> A design pattern that sends a small share of traffic to a new release and widens the share only while its error and latency stay within limits.

Record: `architecture:canary-deployment`
Kind: pattern
Layer: [Correctness Core](https://banes-lab.com/records/layer/correctness-core.md)
Severity: contextual
Scope: deployment, release
Canonical: https://banes-lab.com/ontology#architecture-canary-deployment

Listed in [Architecture principles](https://banes-lab.com/api/records/architecture.md), after [Blue-Green Deployment](https://banes-lab.com/records/architecture/blue-green-deployment.md) and before [Chaos Engineering](https://banes-lab.com/records/architecture/chaos-engineering.md).

## Repair

- Refactored by: Add Canary Stage, Add Automated Guardrails
- Detected by: no staged traffic policy
- Violated by: full rollout without health/error guard
- Measured by: canary error budget, rollback trigger rate
- Enforced by: deployment pipeline

## Requires

- [Traffic Splitting](https://banes-lab.com/records/lexicon/traffic-splitting.md)
- [Observability](https://banes-lab.com/records/architecture/observability.md)

## Reinforces

- [Progressive Delivery](https://banes-lab.com/records/lexicon/progressive-delivery.md)

## Enables

- [Controlled Exposure](https://banes-lab.com/records/lexicon/controlled-exposure.md)

## Conflicts with

- [Big-Bang Release](https://banes-lab.com/records/architecture/big-bang-release.md)

## In tension with

- [Rollout Complexity](https://banes-lab.com/records/lexicon/rollout-complexity.md)

## Tensions

- [Canary Deployment / Rollout Complexity](https://banes-lab.com/records/tension/canary-deployment-rollout-complexity.md)

## Severity

- [contextual](https://banes-lab.com/records/vocabulary/severity-contextual.md)

## Category

- [Self-Healing / Recovery / Deployment Safety](https://banes-lab.com/records/architecture-category/self-healing-recovery-deployment-safety.md)

## Linked from

- [Anti-patterns](https://banes-lab.com/ontology/principles/architecture-category-anti-patterns.md)
- [Observability / Auditability / Traceability](https://banes-lab.com/ontology/principles/architecture-category-observability-auditability-traceability.md)
- [Self-Healing / Recovery / Deployment Safety](https://banes-lab.com/ontology/lexicon/lexicon-category-self-healing-recovery-deployment-safety.md)
- [Severity levels](https://banes-lab.com/ontology/schema/the-vocabulary-severity.md)
- [The resolutions](https://banes-lab.com/ontology/schema/the-resolutions.md)