---
title: "Session: Production Hardening rotatingMachine + machineGroupControl"
created: 2026-04-07
updated: 2026-04-07
status: proven
tags: [session, rotatingMachine, machineGroupControl, testing]
---

# 2026-04-07 — Production Hardening

## Scope
Full code review and hardening of rotatingMachine and machineGroupControl nodes for production readiness.

## Key Discoveries

1. **Efficiency rounding destroyed NCog/BEP** — `Math.round(Q/P * 100) / 100` in canonical units (m3/s and W) produces ratios ~1e-6 that all round to 0. All NCog, cog, and BEP calculations were non-functional. Fixed by removing rounding.

2. **flowmovement unit mismatch** — machineGroupControl computed flow in canonical (m3/s) and sent it directly to rotatingMachine which expected output units (m3/h). Every pump stayed at minimum flow. Fixed with `_canonicalToOutputFlow()`.

3. **emergencyStop case mismatch** — `"emergencyStop"` vs config key `"emergencystop"`. Emergency stop never worked. Fixed to lowercase.

4. **Curve data anomalies** — 3 flow values leaked into power columns in hidrostal-H05K-S03R.json at pressures 1600, 3200, 3300 mbar. Fixed with interpolated values.

5. **C5 pump non-convexity** — 5 data points per pressure level produces non-convex spline. The marginal-cost refinement loop closes the gap to brute-force optimum from 2.1% to 0.1%.

## Changes Made

### rotatingMachine (3 files, 7 test files)
- Async input handler, null guards, listener cleanup, tick loop race fix
- showCoG() implementation, efficiency variant fix, curve anomaly detection
- 43 new tests (76 total)

### machineGroupControl (1 file, 2 test files)
- `_canonicalToOutputFlow()` on all flowmovement calls
- Absolute scaling bug, empty Qd block, empty-machines guards
- Marginal-cost refinement loop in BEP-Gravitation
- Missing flowmovement after startup in equalFlowControl

### generalFunctions (1 file)
- 3 curve data fixes in hidrostal-H05K-S03R.json

## Verification
- 90 tests passing across both nodes
- machineGroupControl within 0.1% of brute-force global optimum (1000-step search)
- Pump switching stable: 1-2 transitions across full demand range, no hysteresis
- Optimization cost: 0.03-0.15ms per call (0.015% of tick budget)