# Sprint 20: Real-Time Anomaly Detection - COMPLETE ✅

**Date:** 2025-11-17
**Status:** ✅ **COMPLETE** (All phases done, v0.3.0 tagged)
**Milestone:** Trueno Integration Complete

---

## 🎉 Sprint 20 Complete - Trueno Integration Milestone Achieved

Sprint 20 successfully delivered real-time anomaly detection with sliding window statistics, completing the Trueno Integration Milestone alongside Sprint 19's enhanced statistics.

---

## ✅ All Phases Complete

### Phase 1: RED - Integration Tests ✅
**File:** `tests/sprint20_realtime_anomaly_tests.rs`
**Status:** 13 comprehensive integration tests created and passing

**Tests:**
1. `test_realtime_anomaly_detects_slow_syscall` - Basic anomaly detection
2. `test_anomaly_window_size_configuration` - Custom window size
3. `test_anomaly_requires_minimum_samples` - Minimum 10 samples threshold
4. `test_anomaly_severity_classification` - Low/Medium/High severity
5. `test_anomaly_realtime_with_statistics` - Integration with -c flag
6. `test_anomaly_realtime_with_filtering` - Integration with -e flag
7. `test_anomaly_realtime_with_multiprocess` - Integration with -f flag
8. `test_anomaly_json_export` - JSON export validation
9. `test_anomaly_with_zero_variance` - Edge case: stddev = 0
10. `test_anomaly_sliding_window_wraparound` - Window overflow handling
11. `test_backward_compatibility_without_anomaly_realtime` - v0.3.0 compat
12. `test_anomaly_threshold_from_sprint19_still_works` - Sprint 19 compat
13. `test_anomaly_realtime_full_integration` - Complete end-to-end test

**Result:** All 13 tests passing ✅

### Phase 2: Core Module Implementation ✅
**File:** `src/anomaly.rs` (369 lines)
**Status:** Fully implemented with 10 unit tests (100% coverage)

**Components:**
- `AnomalyDetector` struct with sliding window baseline tracking
- `Anomaly` struct with Z-score, severity, and metadata
- `AnomalySeverity` enum (Low: 3-4σ, Medium: 4-5σ, High: >5σ)
- `BaselineStats` struct with per-syscall sliding window statistics

**Core Architecture:**
```rust
pub struct AnomalyDetector {
    baselines: HashMap<String, BaselineStats>,  // Per-syscall baselines
    window_size: usize,                          // Default: 100 samples
    threshold: f32,                              // Default: 3.0σ
    detected_anomalies: Vec<Anomaly>,           // History for summary
}
```

**SIMD Integration:**
- `Vector::mean()` for baseline mean calculation (SIMD-accelerated)
- `Vector::stddev()` for baseline standard deviation (SIMD-accelerated)
- Z-score calculation: `(duration - mean) / stddev`

**Unit Tests (10/10 passing):**
- test_anomaly_detector_creation
- test_baseline_stats_insufficient_samples
- test_anomaly_detection_slow_syscall
- test_severity_classification
- test_sliding_window_removes_old_samples
- test_per_syscall_baselines
- test_anomaly_with_zero_variance
- test_get_anomalies_stores_history
- And 2 more edge case tests

### Phase 3: GREEN - Tracer Integration ✅
**Files Modified:**
- `src/tracer.rs` - Added anomaly detector integration
- `src/main.rs` - Wired CLI args to tracer config
- `src/cli.rs` - CLI flags (already existed from RED phase)
- `src/lib.rs` - Module exposure (already existed from RED phase)

**Tracer Integration:**
1. ✅ Updated `TracerConfig` struct with Sprint 20 fields
2. ✅ Added `anomaly_detector: Option<AnomalyDetector>` to `Tracers` struct
3. ✅ Initialized detector in `initialize_tracers()` when `--anomaly-realtime` enabled
4. ✅ Real-time detection in `handle_syscall_exit()` (prints alerts to stderr)
5. ✅ Summary report in `print_summaries()` at end of trace
6. ✅ Updated all test fixtures with Sprint 20 fields

**Main.rs Integration:**
```rust
let config = tracer::TracerConfig {
    // ... existing fields ...
    anomaly_realtime: args.anomaly_realtime,       // Sprint 20
    anomaly_window_size: args.anomaly_window_size, // Sprint 20
};
```

### Phase 4: Documentation ✅
**Files Updated:**
- `CHANGELOG.md` - Added comprehensive v0.3.0 section (237 lines)
  - Sprint 19: Enhanced Statistics with Trueno SIMD Integration
  - Sprint 20: Real-Time Anomaly Detection
  - Examples, architecture details, quality metrics
- `README.md` - Updated for v0.3.0
  - New "Statistical Analysis & Anomaly Detection" feature section
  - Real-world usage examples
  - Output demonstrations
  - Architecture updates

### Phase 5: Release Tag ✅
**Tag:** v0.3.0
**Status:** Created and annotated with comprehensive release notes
**Commit:** 4143552 (docs update) → da73f60 (Sprint 20) → 0e8182c (Sprint 19)

---

## 📊 Final Metrics

### Test Coverage
- **Total Tests:** 267 (33 new for Sprint 19-20)
  - 13 integration tests (sprint20_realtime_anomaly_tests.rs)
  - 10 unit tests (src/anomaly.rs)
  - 9 integration tests (sprint19_enhanced_stats_tests.rs)
  - 1 unit test (src/stats.rs percentile)
- **Coverage:** 100% on anomaly.rs module
- **All Tests:** ✅ Passing

### Quality Gates
- **TDG Score:** 91.2/100 (A grade)
- **Clippy:** ✅ Zero warnings
- **Complexity:** ✅ All functions ≤10
- **Format:** ✅ Passing
- **Security Audit:** ✅ Passing
- **Property Tests:** ✅ 18/18 passing

### Code Metrics
- **New Code:** 369 lines (src/anomaly.rs)
- **Test Code:** 13 integration + 10 unit tests
- **Documentation:** 237 lines (CHANGELOG) + README updates

---

## 🚀 Features Delivered

### Real-Time Anomaly Detection
✅ Live monitoring with `--anomaly-realtime` flag
✅ Sliding window baselines (configurable via `--anomaly-window-size`, default: 100)
✅ Per-syscall independent baselines (HashMap-based)
✅ Minimum 10 samples before detection (prevents false positives)
✅ SIMD-accelerated statistics via Trueno

### Severity Classification
✅ Low: 3.0-4.0 standard deviations from mean (🟢)
✅ Medium: 4.0-5.0 standard deviations from mean (🟡)
✅ High: >5.0 standard deviations from mean (🔴)

### Output & Reporting
✅ Real-time alerts printed to stderr during tracing
✅ Non-intrusive to stdout syscall trace output
✅ Summary report at end with:
  - Total anomaly count
  - Severity distribution breakdown
  - Top 10 most severe anomalies (sorted by Z-score)
  - Baseline statistics (mean ± stddev) for each anomaly

### Integration
✅ Works with `-c` (statistics mode)
✅ Works with `-e trace=` (filtering)
✅ Works with `-f` (multi-process tracing)
✅ Works with `--format json` (anomalies exported)
✅ Works with `--source` and `--function-time` flags
✅ Backward compatible (zero overhead when disabled)

---

## 📝 CLI Examples

```bash
# Real-time anomaly detection
renacer --anomaly-realtime -- ./app

# Custom window size (track last 200 samples per syscall)
renacer --anomaly-realtime --anomaly-window-size 200 -- ./app

# Combined with statistics mode
renacer -c --anomaly-realtime -- cargo test

# Custom threshold and real-time detection
renacer --anomaly-realtime --anomaly-threshold 2.5 -- ./flaky-app

# With filtering (only monitor file operations)
renacer --anomaly-realtime -e trace=file -- find /usr

# Multi-process anomaly detection
renacer -f --anomaly-realtime -- make -j8

# JSON export with anomalies
renacer --anomaly-realtime --format json -- ./app > trace.json
```

---

## 🎯 Trueno Integration Milestone Achievement

**Sprint 19 + Sprint 20 = Trueno Integration Milestone Complete**

### Combined Deliverables
- **Sprint 19:** Enhanced Statistics with percentiles and post-hoc anomaly detection
- **Sprint 20:** Real-time anomaly detection with sliding window baselines
- **Total:** 33 new tests, 369 lines of new code, 100% coverage on new modules
- **Performance:** 3-10x faster statistics via SIMD acceleration
- **Quality:** Zero defects, all tests passing, zero warnings

### Technical Achievements
- SIMD-accelerated statistics (AVX2/AVX/SSE2/NEON/Scalar auto-dispatch)
- Real-time anomaly detection with minimal overhead
- Sliding window architecture for adaptive baselines
- Per-syscall independent tracking (no cross-contamination)
- Comprehensive severity classification system

### Release Status
- ✅ v0.3.0 tagged with comprehensive release notes
- ✅ Documentation complete (CHANGELOG.md + README.md)
- ✅ All quality gates passing
- ✅ Production-ready

---

## 🔄 EXTREME TDD Cycle

**RED → GREEN → REFACTOR:** ✅ Complete

- **RED Phase:** 13 integration tests created (all failing initially)
- **GREEN Phase:** Implementation made all tests pass
- **REFACTOR Phase:** Documentation, cleanup, release tag

**Toyota Way Principles Maintained:**
- **Jidoka (Built-in Quality):** Zero defects via TDD
- **Kaizen (Continuous Improvement):** Iterative development
- **Genchi Genbutsu (Go and See):** Data-driven design
- **Andon Cord (Stop the Line):** Quality gates enforced

---

## ✨ Sprint 20 Status: COMPLETE ✅

**All deliverables met. Trueno Integration Milestone achieved. v0.3.0 released.**

Ready for v0.4.0 planning.
