# Canary Deployment Controller with Auto-Advance, Statistical Analysis, and Auto-Rollback

## Module
ReleaseOrchestrator

## Status
VERIFIED

## Description
Canary controller for gradual traffic promotion through configurable steps (e.g., 5% -> 10% -> 25% -> 50% -> 100%) with multiple progression strategies (linear, exponential, fibonacci). Auto-advances based on statistical metrics analysis, auto-rolls back on metric threshold breaches, supports manual intervention and configurable promotion schedules.

## Implementation Details
- **Modules**: `src/ReleaseOrchestrator/__Libraries/StellaOps.ReleaseOrchestrator.ProgressiveDelivery/`, `src/ReleaseOrchestrator/__Libraries/StellaOps.ReleaseOrchestrator.Progressive/Canary/`
- **Key Classes**:
  - `CanaryController` (`src/ReleaseOrchestrator/__Libraries/StellaOps.ReleaseOrchestrator.ProgressiveDelivery/CanaryController.cs`) - canary controller with statistical analysis and auto-advance/rollback
  - `CanaryController` (`src/ReleaseOrchestrator/__Libraries/StellaOps.ReleaseOrchestrator.Progressive/Canary/CanaryController.cs`) - canary controller implementation
  - `TrafficManager` (`src/ReleaseOrchestrator/__Libraries/StellaOps.ReleaseOrchestrator.ProgressiveDelivery/TrafficManager.cs`) - manages traffic distribution during canary phases
  - `CanaryDeploymentStrategy` (`src/ReleaseOrchestrator/__Libraries/StellaOps.ReleaseOrchestrator.Deployment/Orchestrator/RollingDeploymentStrategy.cs`) - canary deployment strategy implementation
- **Interfaces**: `ICanaryController`, `ITrafficManager`, `IDeploymentStrategy`
- **Source**: SPRINT_20260110_110_003_PROGDL_canary_controller.md

## E2E Test Plan
- [ ] Start a canary deployment with 5% initial traffic and verify only 5% of traffic goes to the canary
- [ ] Verify auto-advance: metrics remain healthy and traffic automatically advances to the next step (10%)
- [ ] Verify auto-rollback: inject a metric threshold breach and confirm traffic rolls back to 0% canary
- [ ] Verify progression strategies: configure fibonacci progression and verify steps follow 5%, 8%, 13%, 21%, ...
- [ ] Verify manual intervention: pause auto-advance and manually promote the canary


## Verification
- **Verified**: 2026-02-13T21:00:00Z
- **Method**: Tier 2d integration tests
- **Result**: PASS