# StellaRouter Performance Testing Pipeline (k6 + Prometheus + Correlation IDs)

## Module
Gateway

## Status
VERIFIED

## Description
Performance testing pipeline with k6 load test scenarios (A-G), correlation ID instrumentation, Prometheus-compatible metrics, and Grafana dashboards for performance curve modeling.

## Implementation Details
- **k6 load tests**: `src/Gateway/__Tests/load/gateway_performance.k6.js` -- 7 scenarios A-G (511 lines)
- **Performance metrics**: `src/Gateway/StellaOps.Gateway.WebService/Services/GatewayPerformanceMetrics.cs` -- Prometheus counters/histograms + scenario config models (318 lines)
- **Correlation ID middleware**: `src/Gateway/StellaOps.Gateway.WebService/Middleware/CorrelationIdMiddleware.cs` -- correlation ID propagation with validation (64 lines)
- **Gateway metrics**: `src/Gateway/StellaOps.Gateway.WebService/Services/GatewayMetrics.cs` -- base Prometheus metrics
- **Health monitoring**: `src/Gateway/StellaOps.Gateway.WebService/Services/GatewayHealthMonitorService.cs`
- **Grafana dashboard**: `devops/telemetry/dashboards/stella-ops-gateway-performance.json`
- Source: Feature matrix scan

## E2E Test Plan
- [x] Verify k6 scenarios A-G exist and cover the required traffic patterns
- [x] Test correlation ID propagation overhead measurement
- [x] Verify Prometheus metrics are exposed correctly
- [x] Verify Grafana dashboard exists

## Verification
- **Run ID**: run-002
- **Date**: 2026-02-09
- **Method**: Tier 1 code review + Tier 2d integration tests
- **Build**: PASS (0 errors, 0 warnings)
- **Tests**: PASS (202/202 gateway tests pass)
- **Code Review**:
  - k6 script (511 lines): All 7 scenarios verified: A (health baseline), B (OpenAPI under load), C (routing throughput), D (correlation ID overhead), E (rate limit boundary), F (connection ramp/saturation), G (sustained soak).
  - GatewayPerformanceMetrics (318 lines): Prometheus counters (requests, errors, rate-limits), histograms (request/auth/transport/routing durations), scenario config models with PerformanceCurvePoint.
  - GatewayPerformanceMetricsTests (418 lines, 20+ tests): Verify scenario configs, curve point computed properties, threshold violations, observation recording.
  - CorrelationIdMiddlewareTests (71 lines, 4 tests): ID generation, echo, TraceIdentifier sync.
  - Note: Feature file's "What's Missing" section is STALE -- k6 scripts and Grafana dashboard DO exist.
- **Verdict**: PASS

## Tier 2 Recheck (2026-02-10)
- **Run ID**: run-003
- **Result**: PASS
- **What was rechecked**: `/metrics` and correlation-id live behavior replay, instrumentation test suite pass, and k6 scenario script presence.
- **Evidence**: `docs/qa/feature-checks/runs/gateway/stellarouter-performance-testing-pipeline/run-003/tier2-integration-check.json`

## Recheck (run-005)
- **Date**: 2026-02-10
- **Result**: PASS
- **Verification**: Performance instrumentation and metrics/correlation behavior remain stable.
- **Tests**: Gateway.WebService.Tests 259/259, Router Gateway WebService.Tests 160/160, Router.Gateway.Tests 13/13 (432 total).
- **Evidence**: `docs/qa/feature-checks/runs/gateway/stellarouter-performance-testing-pipeline/run-005/tier2-integration-check.json`


## Recheck (Run-006)
- **Verified**: 2026-02-10
- **Method**: Tier 2 replay + full Gateway/Router matrix.
- **Tests**: PASS (`src/Gateway/__Tests/StellaOps.Gateway.WebService.Tests`: 259/259; `src/Router/__Tests/StellaOps.Gateway.WebService.Tests`: 160/160; `src/Router/__Tests/StellaOps.Router.Gateway.Tests`: 13/13).
- **Tier 2 Evidence**: `docs/qa/feature-checks/runs/gateway/stellarouter-performance-testing-pipeline/run-006/tier2-integration-check.json`
- **Outcome**: Checked Gateway feature behavior remains stable in follow-up replay.

## Recheck (Run-007)
- **Verified**: 2026-02-10
- **Method**: Tier 2 integration replay.
- **Tests**: PASS (src/Gateway/__Tests/StellaOps.Gateway.WebService.Tests: 259/259; src/Router/__Tests/StellaOps.Gateway.WebService.Tests: 160/160; src/Router/__Tests/StellaOps.Router.Gateway.Tests: 13/13).
- **Tier 2 Evidence**: `docs/qa/feature-checks/runs/gateway/stellarouter-performance-testing-pipeline/run-007/tier2-integration-check.json`
- **Outcome**: Gateway/Router behavior for this checked feature remains healthy.
## Recheck (Run-008)
- **Verified**: 2026-02-10
- **Method**: Tier 2 replay with deterministic Gateway+Router suite verification.
- **Tests**: PASS (src/Gateway/__Tests/StellaOps.Gateway.WebService.Tests: 259/259; src/Router/__Tests/StellaOps.Gateway.WebService.Tests: 160/160; src/Router/__Tests/StellaOps.Router.Gateway.Tests: 13/13).
- **Tier 2 Evidence**: docs/qa/feature-checks/runs/gateway/stellarouter-performance-testing-pipeline/run-008/tier2-integration-check.json
- **Outcome**: Checked gateway behavior remains healthy in continued replay.

## Recheck (Run-009)
- **Verified**: 2026-02-10
- **Method**: Tier 2 replay with deterministic Gateway+Router suite verification.
- **Tests**: PASS (src/Gateway/__Tests/StellaOps.Gateway.WebService.Tests: 259/259; src/Router/__Tests/StellaOps.Gateway.WebService.Tests: 160/160; src/Router/__Tests/StellaOps.Router.Gateway.Tests: 13/13).
- **Tier 2 Evidence**: docs/qa/feature-checks/runs/gateway/stellarouter-performance-testing-pipeline/run-009/tier2-integration-check.json
- **Outcome**: Checked gateway behavior remains healthy in continued replay.

## Recheck (Run-010)
- **Verified**: 2026-02-10
- **Method**: Tier 2d deterministic integration replay.
- **Tests**: PASS (Gateway.WebService.Tests 259/259, Router.Gateway.WebService.Tests 160/160, Router.Gateway.Tests 13/13).
- **Tier 2 Evidence**: docs/qa/feature-checks/runs/gateway/stellarouter-performance-testing-pipeline/run-010/tier2-integration-check.json
- **Outcome**: Checked Gateway behavior remains healthy in continued replay.


## Recheck (Run-011)
- **Verified**: 2026-02-10
- **Method**: Tier 2d deterministic integration replay.
- **Tests**: PASS (Gateway.WebService 259/259, Router.Gateway.WebService 160/160, Router.Gateway 13/13; total 432/432).
- **Tier 2 Evidence**: docs/qa/feature-checks/runs/gateway/stellarouter-performance-testing-pipeline/run-011/tier2-integration-check.json
- **Outcome**: Checked gateway behavior remains healthy in continued replay.
## Recheck (Run-012)
- **Verified**: 2026-02-10
- **Method**: Tier 2d deterministic integration replay.
- **Tests**: PASS (Gateway.WebService 259/259, Router.Gateway.WebService 160/160, Router.Gateway 13/13; total 432/432).
- **Tier 2 Evidence**: docs/qa/feature-checks/runs/gateway/stellarouter-performance-testing-pipeline/run-012/tier2-integration-check.json
- **Outcome**: Checked gateway behavior remains healthy in continued replay.