7894d39f1c
Replace the LogisticRegression meta-learner with a PyTorch MetaFusionMLP (Linear(3,16)->BN->ReLU->Dropout->Linear(16,1)->Sigmoid) for non-linear fusion of EIF, NF, and XGBoost scores. Replace KS-test + quantile digest drift detection with ADWIN (adaptive sliding window, Hoeffding bound). Replace weekly XGBoost batch retraining with River HoeffdingAdaptiveTree for incremental online learning (learn_one per cycle). Update all thesis documentation sections (2.4.2c, 2.4.3, 3.8, discussion, conclusion). Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
584 lines
27 KiB
Python
584 lines
27 KiB
Python
"""Gestion des modèles : chargement, entraînement, versionnement.
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IsolationForest (EIF), Normalizing Flow (PyTorch/FrEIA), Hoeffding Adaptive Tree (River).
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"""
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import os
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import json
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import glob
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import pickle
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import joblib
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import numpy as np
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import pandas as pd
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from datetime import datetime
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from .config import (
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MODEL_DIR, MODEL_HISTORY_COUNT, RETRAIN_INTERVAL_H, DRIFT_THRESHOLD,
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N_ESTIMATORS, CONTAMINATION, ANOMALY_THRESHOLD, AE_WEIGHT, AE_EPOCHS, AE_LATENT_DIM,
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AE_LEARNING_RATE, XGB_WEIGHT, XGB_MIN_LABELS, XGB_RETRAIN_INTERVAL_H,
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EIF_AVAILABLE, TORCH_AVAILABLE, XGB_AVAILABLE, DB,
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IsolationForest, StandardScaler,
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)
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from .log import log_info, log_decision, append_training_history
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from .scoring import ADWINDriftMonitor
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# Imports conditionnels depuis config (déjà importés une seule fois)
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if EIF_AVAILABLE:
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from .config import ExtendedIsolationForest
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if TORCH_AVAILABLE:
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from .config import torch, nn
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try:
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from river import forest as river_forest
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RIVER_AVAILABLE = True
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except ImportError:
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RIVER_AVAILABLE = False
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if XGB_AVAILABLE:
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import xgboost as xgb
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from sklearn.model_selection import cross_val_predict
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try:
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from cleanlab.filter import find_label_issues
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CLEANLAB_AVAILABLE = True
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except ImportError:
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CLEANLAB_AVAILABLE = False
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else:
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CLEANLAB_AVAILABLE = False
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# ─── Caches de modèles ─────────────────────────────────────────────────────
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_model_cache: dict = {}
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_xgb_cache: dict = {}
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_drift_monitors: dict[str, ADWINDriftMonitor] = {}
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# ═══════════════════════════════════════════════════════════════════════════════
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# GESTION DES MODÈLES
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# ═══════════════════════════════════════════════════════════════════════════════
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def _current_pointer_path(name: str) -> str:
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"""Retourne le chemin du fichier pointeur vers la version courante du modèle ``name``."""
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return os.path.join(MODEL_DIR, f'model_{name}.current')
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def _get_current_version(name: str):
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"""Lit le fichier pointeur et retourne (chemin_modèle, métadonnées) ou (None, None) si absent."""
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pointer = _current_pointer_path(name)
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if not os.path.exists(pointer): return None, None
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with open(pointer) as f: version_id = f.read().strip()
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model_path = os.path.join(MODEL_DIR, f'model_{name}_{version_id}.joblib')
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meta_path = os.path.join(MODEL_DIR, f'model_{name}_{version_id}.meta.json')
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if not os.path.exists(model_path) or not os.path.exists(meta_path): return None, None
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with open(meta_path) as f: meta = json.load(f)
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return model_path, meta
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def _purge_old_versions(name: str):
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"""Supprime les versions excédentaires du modèle ``name`` en ne conservant que MODEL_HISTORY_COUNT fichiers."""
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pattern = os.path.join(MODEL_DIR, f'model_{name}_*.joblib')
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versions = sorted(glob.glob(pattern))
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to_delete = versions[:-MODEL_HISTORY_COUNT] if len(versions) > MODEL_HISTORY_COUNT else []
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for joblib_path in to_delete:
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version_id = os.path.basename(joblib_path).replace(f'model_{name}_', '').replace('.joblib', '')
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meta_path = os.path.join(MODEL_DIR, f'model_{name}_{version_id}.meta.json')
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os.remove(joblib_path)
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if os.path.exists(meta_path): os.remove(meta_path)
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log_info(f"[{name}] Version purgée : {version_id} (limite={MODEL_HISTORY_COUNT})")
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# ═══════════════════════════════════════════════════════════════════════════════
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# AUTOENCODER — Second scorer parallèle (détection d'anomalies par reconstruction)
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# ═══════════════════════════════════════════════════════════════════════════════
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class TrafficNormalizingFlow:
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"""Normalizing Flow (RealNVP) pour détection d'anomalies par vraisemblance.
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Architecture : 4 blocs de couplage affine (AllInOneBlock), sous-réseaux MLP
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(2 couches, 64 neurones, ReLU). L'espace latent = input_dim (pas de bottleneck).
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Score d'anomalie = -log p(x), estimé via le changement de variable.
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L'espace latent peut servir de features compressées pour HDBSCAN.
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"""
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def __init__(self, n_features: int, latent_dim: int = 0):
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if not TORCH_AVAILABLE:
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raise RuntimeError("PyTorch non disponible — Normalizing Flow désactivé.")
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try:
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import FrEIA.framework as Ff
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import FrEIA.modules as Fm
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except ImportError:
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raise RuntimeError("FrEIA non disponible — installer : pip install FrEIA")
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self.n_features = n_features
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self.device = torch.device('cpu')
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self._build_model()
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self._scaler_min = None
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self._scaler_range = None
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def _subnet_fc(self, c_in, c_out):
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"""Sous-réseau MLP pour les blocs de couplage (2 couches, 64 neurones)."""
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return nn.Sequential(
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nn.Linear(c_in, 64), nn.ReLU(),
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nn.Linear(64, 64), nn.ReLU(),
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nn.Linear(64, c_out),
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)
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def _build_model(self):
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import FrEIA.framework as Ff
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import FrEIA.modules as Fm
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nodes = [Ff.InputNode(self.n_features, name='input')]
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for i in range(4):
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nodes.append(Ff.Node(
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nodes[-1],
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Fm.AllInOneBlock,
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{'subnet_constructor': self._subnet_fc, 'affine_clamping': 2.0},
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name=f'coupling_{i}',
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))
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nodes.append(Ff.OutputNode(nodes[-1], name='output'))
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self.flow = Ff.GraphINN(nodes, verbose=False).to(self.device)
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def _to_tensor(self, X: np.ndarray) -> 'torch.Tensor':
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"""Normalise [0,1] via min-max puis convertit en Tensor."""
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if self._scaler_min is not None:
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X_norm = (X - self._scaler_min) / (self._scaler_range + 1e-9)
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else:
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X_norm = X
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return torch.tensor(np.clip(X_norm, 0, 1), dtype=torch.float32, device=self.device)
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def log_likelihood(self, x: 'torch.Tensor') -> 'torch.Tensor':
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"""Calcule log p(x) = log p_z(f(x)) + log|det J_f(x)|."""
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z, log_det = self.flow(x)
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log_pz = -0.5 * (z ** 2).sum(dim=1) - 0.5 * self.n_features * np.log(2 * np.pi)
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return log_pz + log_det
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def fit(self, X: np.ndarray, epochs: int = AE_EPOCHS, lr: float = AE_LEARNING_RATE,
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batch_size: int = 256) -> dict:
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"""Entraîne le Normalizing Flow sur la baseline humaine (données normales)."""
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self._scaler_min = X.min(axis=0)
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self._scaler_range = X.max(axis=0) - self._scaler_min
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X_t = self._to_tensor(X)
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dataset = torch.utils.data.TensorDataset(X_t)
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loader = torch.utils.data.DataLoader(dataset, batch_size=batch_size, shuffle=True)
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optimizer = torch.optim.Adam(self.flow.parameters(), lr=lr, weight_decay=1e-5)
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self.flow.train()
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losses = []
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for epoch in range(epochs):
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epoch_loss = 0.0
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for (batch,) in loader:
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log_p = self.log_likelihood(batch)
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loss = -log_p.mean() # NLL
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optimizer.zero_grad()
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loss.backward()
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optimizer.step()
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epoch_loss += loss.item() * len(batch)
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losses.append(epoch_loss / len(X_t))
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return {'final_loss': losses[-1], 'epochs': epochs, 'n_samples': len(X)}
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def score_samples(self, X: np.ndarray) -> np.ndarray:
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"""Retourne -log p(x) par échantillon (plus élevé = plus anomal)."""
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self.flow.eval()
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X_t = self._to_tensor(X)
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with torch.no_grad():
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return -self.log_likelihood(X_t).numpy()
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def encode(self, X: np.ndarray) -> np.ndarray:
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"""Retourne l'espace latent z = f(x) (pour HDBSCAN clustering)."""
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self.flow.eval()
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X_t = self._to_tensor(X)
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with torch.no_grad():
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z, _ = self.flow(X_t)
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return z.numpy()
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def state_dict(self) -> dict:
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return {
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'flow': self.flow.state_dict(),
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'scaler_min': self._scaler_min,
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'scaler_range': self._scaler_range,
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'n_features': self.n_features,
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}
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@classmethod
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def load_state_dict(cls, state: dict) -> 'TrafficNormalizingFlow':
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nf = cls(state['n_features'])
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nf._scaler_min = state['scaler_min']
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nf._scaler_range = state['scaler_range']
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nf.flow.load_state_dict(state['flow'])
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return nf
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def _ae_model_path(name: str, version_id: str) -> str:
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return os.path.join(MODEL_DIR, f'ae_{name}_{version_id}.pt')
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# ═══════════════════════════════════════════════════════════════════════════════
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# XGBOOST — Troisième voix supervisée (labels historiques + feedback SOC)
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# ═══════════════════════════════════════════════════════════════════════════════
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def _xgb_model_path(name: str) -> str:
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return os.path.join(MODEL_DIR, f'xgb_{name}.json')
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def _xgb_meta_path(name: str) -> str:
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return os.path.join(MODEL_DIR, f'xgb_{name}.meta.json')
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def _load_xgb_labels(client, features: list, min_labels: int = XGB_MIN_LABELS) -> tuple:
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"""Charge les labels historiques depuis ml_all_scores + view_ai_features_1h.
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Les labels (threat_level) viennent de ml_all_scores, les features de
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view_ai_features_1h via une jointure sur (src_ip, ja4, host).
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Les features absentes de la vue (ex: thesis §5 features) sont ignorées.
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Positifs : threat_level IN ('HIGH', 'CRITICAL', 'ANUBIS_DENY', 'KNOWN_BOT') → label=1
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Négatifs : threat_level IN ('NORMAL', 'LEGITIMATE_BROWSER') → label=0
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Retourne (X, y, usable_features) ou (None, None, None) si insuffisant.
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"""
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try:
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# Découvrir les colonnes disponibles dans la vue
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cols_result = client.query(
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f"SELECT name FROM system.columns "
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f"WHERE database = '{DB}' AND table = 'view_ai_features_1h'"
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)
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available_cols = {row[0] for row in cols_result.result_rows} if cols_result.result_rows else set()
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usable_features = [f for f in features if f in available_cols]
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if len(usable_features) < 10:
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log_info(f"[XGB] Seulement {len(usable_features)} features disponibles dans view_ai_features_1h — insuffisant.")
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return None, None, None
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feature_cols = ', '.join(f'f.{c}' for c in usable_features)
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result = client.query(
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f"SELECT {feature_cols}, s.threat_level "
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f"FROM {DB}.ml_all_scores AS s "
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f"INNER JOIN {DB}.view_ai_features_1h AS f "
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f" ON s.src_ip = f.src_ip AND s.ja4 = f.ja4 AND s.host = f.host "
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f"WHERE s.threat_level IN ('NORMAL', 'LEGITIMATE_BROWSER', 'HIGH', 'CRITICAL', 'ANUBIS_DENY', 'KNOWN_BOT') "
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f"AND s.window_start >= now() - INTERVAL 7 DAY "
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f"ORDER BY rand() LIMIT 50000"
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)
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if not result.result_rows:
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return None, None, None
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cols = usable_features + ['threat_level']
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df = pd.DataFrame(result.result_rows, columns=cols)
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df[usable_features] = df[usable_features].apply(pd.to_numeric, errors='coerce')
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df = df.replace([np.inf, -np.inf], np.nan).dropna(subset=usable_features)
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y = (~df['threat_level'].isin(['NORMAL', 'LEGITIMATE_BROWSER'])).astype(int)
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if y.sum() < 10 or len(y) < min_labels:
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return None, None, None
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X = df[usable_features].values
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return X, y.values, usable_features
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except Exception as exc:
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log_info(f"[XGB] Erreur chargement labels : {exc}")
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return None, None, None
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def load_or_train_xgb(name: str, client, features: list, cycle_id: str):
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"""Charge ou met à jour le modèle supervisé en ligne (Hoeffding Adaptive Tree).
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Remplace le XGBClassifier hebdomadaire par un HoeffdingAdaptiveTreeClassifier
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de River, mis à jour incrémentalement à chaque cycle via learn_one().
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Retourne (model, list[str] features) ou (None, None) si indisponible.
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Le model retourné expose predict_proba_many(df) → DataFrame.
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"""
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if not (XGB_AVAILABLE or RIVER_AVAILABLE) or XGB_WEIGHT <= 0:
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return None, None
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model_path = _river_model_path(name)
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meta_path = _xgb_meta_path(name)
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# Charger le modèle River existant
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model = None
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xgb_features = features
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n_seen = 0
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if os.path.exists(model_path):
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try:
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with open(model_path, 'rb') as f:
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model = pickle.load(f)
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with open(meta_path) as f:
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meta = json.load(f)
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xgb_features = meta.get('features', features)
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n_seen = meta.get('n_total_labels', 0)
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log_info(f"[River][{name}] HAT rechargé ({n_seen} labels cumulés, {len(xgb_features)} features).")
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except Exception as exc:
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log_info(f"[River][{name}] Erreur chargement : {exc} — nouveau modèle.")
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model = None
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# Créer un nouveau modèle si nécessaire
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if model is None:
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try:
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model = river_forest.HoeffdingAdaptiveTreeClassifier(
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grace_period=50, max_depth=12, seed=42,
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)
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except Exception:
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# Fallback vers XGBoost batch si River indisponible
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return _load_or_train_xgb_batch(name, client, features, cycle_id)
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# ── Apprentissage incrémental sur les labels du cycle ──────────────
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X, y, usable_features = _load_xgb_labels(client, features)
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if X is not None and usable_features is not None:
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xgb_features = usable_features
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X_df = pd.DataFrame(X, columns=xgb_features)
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n_new = 0
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for i in range(len(X_df)):
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try:
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x_dict = {col: float(X_df.iloc[i][col]) for col in xgb_features}
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model.learn_one(x_dict, int(y[i]))
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n_new += 1
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except Exception:
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continue
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n_seen += n_new
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# Persister le modèle mis à jour
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os.makedirs(os.path.dirname(model_path), exist_ok=True)
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with open(model_path, 'wb') as f:
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pickle.dump(model, f)
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meta = {
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'trained_at': datetime.now().isoformat(),
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'n_total_labels': n_seen,
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'n_new_labels': n_new,
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'n_features': len(xgb_features),
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'features': xgb_features,
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'model_name': name,
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'algorithm': 'HoeffdingAdaptiveTreeClassifier',
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}
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with open(meta_path, 'w') as f:
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json.dump(meta, f, indent=2)
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log_info(f"[River][{name}] +{n_new} labels incrémentaux ({n_seen} total) — HAT mis à jour.")
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log_decision('RIVER_UPDATED', cycle_id, name, meta)
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else:
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if n_seen == 0:
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log_info(f"[River][{name}] Pas de labels — modèle supervisé désactivé ce cycle.")
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return None, None
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log_info(f"[River][{name}] Pas de nouveaux labels — HAT existant réutilisé ({n_seen} labels).")
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return model, xgb_features
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def _river_model_path(name: str) -> str:
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"""Chemin du modèle River sérialisé."""
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return os.path.join(MODEL_DIR, f'river_hat_{name}.pkl')
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|
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def _load_or_train_xgb_batch(name, client, features, cycle_id):
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"""Fallback : entraîne un XGBoost classique si River est indisponible.
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Conservé pour la compatibilité si river n'est pas installé.
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Retourne (XGBClassifier, list[str] features) ou (None, None).
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"""
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if not XGB_AVAILABLE or XGB_WEIGHT <= 0:
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return None, None
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model_path = _xgb_model_path(name)
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meta_path = _xgb_meta_path(name)
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if os.path.exists(model_path) and os.path.exists(meta_path):
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try:
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with open(meta_path) as f:
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meta = json.load(f)
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model = xgb.XGBClassifier()
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model.load_model(model_path)
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return model, meta.get('features', features)
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except Exception:
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pass
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X, y, xgb_features = _load_xgb_labels(client, features)
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if X is None:
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return None, None
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scale_pos = max(1, int((y == 0).sum() / max((y == 1).sum(), 1)))
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model = xgb.XGBClassifier(
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n_estimators=200, max_depth=6, learning_rate=0.1,
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scale_pos_weight=scale_pos, eval_metric='logloss',
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random_state=42, n_jobs=-1, tree_method='hist',
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)
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model.fit(X, y, verbose=False)
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model.save_model(model_path)
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meta = {
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'trained_at': datetime.now().isoformat(),
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'n_labels': len(y), 'n_positive': int(y.sum()),
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'n_negative': int((y == 0).sum()), 'n_features': len(xgb_features),
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'features': xgb_features, 'model_name': name,
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}
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with open(meta_path, 'w') as f:
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json.dump(meta, f, indent=2)
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log_decision('XGB_TRAINED', cycle_id, name, meta)
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return model, xgb_features
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def load_or_train_model(name: str, human_baseline: pd.DataFrame, features: list, cycle_id: str):
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"""Charge le modèle IsolationForest existant ou en entraîne un nouveau si nécessaire.
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Réutilise le modèle si son âge est inférieur à RETRAIN_INTERVAL_H et si aucune
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dérive conceptuelle significative n'est détectée (A1). En cas d'expiration ou de
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dérive, entraîne un nouveau modèle sur ``human_baseline``, le sérialise sur disque,
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met à jour le fichier pointeur et purge les anciennes versions.
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Retourne (IsolationForest, TrafficNormalizingFlow|None, list[str] features).
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"""
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model_path, meta = _get_current_version(name)
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if model_path and meta:
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trained_at = datetime.fromisoformat(meta['trained_at'])
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age_h = (datetime.now() - trained_at).total_seconds() / 3600
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age_ok = age_h < RETRAIN_INTERVAL_H
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# A1 — Dérive conceptuelle via ADWIN (fenêtre glissante adaptative)
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drift_score = 0.0
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drift_forced = False
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# Obtenir ou créer le moniteur ADWIN pour ce modèle
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if name not in _drift_monitors:
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_drift_monitors[name] = ADWINDriftMonitor(features)
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drift_monitor = _drift_monitors[name]
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if drift_monitor.available:
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# Alimenter ADWIN avec les moyennes de features du cycle courant
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feature_means = {}
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for f in features:
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if f in human_baseline.columns:
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feature_means[f] = float(human_baseline[f].mean())
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drift_score = drift_monitor.check_drift(feature_means, name=name, cycle_id=cycle_id)
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if drift_score >= DRIFT_THRESHOLD:
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drift_forced = True
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log_info(f"[{name}] Dérive ADWIN détectée ({drift_score:.0%} features) — retraining forcé.")
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log_decision('DRIFT_DETECTED', cycle_id, name, {
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'version_id': meta['version_id'], 'drift_rate': round(drift_score, 3),
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'drift_threshold': DRIFT_THRESHOLD, 'model_age_hours': round(age_h, 2)
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})
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if age_ok and not drift_forced:
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log_info(f"[{name}] Modèle v{meta['version_id']} valide ({age_h:.1f}h / {RETRAIN_INTERVAL_H}h, drift={drift_score:.0%}) — réutilisation.")
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log_decision('MODEL_LOADED', cycle_id, name, {
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'version_id': meta['version_id'], 'model_age_hours': round(age_h, 2),
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'trained_at': meta['trained_at'], 'human_samples': meta.get('human_samples', '?'),
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'retrain_in_hours': round(RETRAIN_INTERVAL_H - age_h, 1), 'drift_score': round(drift_score, 3)
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})
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ae_loaded = None
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if TORCH_AVAILABLE and AE_WEIGHT > 0:
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ae_path = _ae_model_path(name, meta['version_id'])
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if os.path.exists(ae_path):
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try:
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ae_loaded = TrafficNormalizingFlow.load_state_dict(torch.load(ae_path, weights_only=False))
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log_info(f"[{name}] Normalizing Flow v{meta['version_id']} rechargé.")
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except Exception as exc:
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log_info(f"[{name}] Erreur chargement AE : {exc} — AE désactivé ce cycle.")
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return joblib.load(model_path), ae_loaded, meta.get('features', features)
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elif not drift_forced:
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log_info(f"[{name}] Modèle v{meta['version_id']} expiré ({age_h:.1f}h ≥ {RETRAIN_INTERVAL_H}h) — retraining.")
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version_id = datetime.now().strftime('%Y%m%d_%H%M%S')
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log_info(f"[{name}] Entraînement EIF v{version_id} — {len(human_baseline)} sessions ISP, {len(features)} features, contamination={CONTAMINATION}")
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X = human_baseline[features].replace([np.inf, -np.inf], np.nan)
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X = X.fillna(X.median())
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# Feature pruning : retirer les features à variance quasi-nulle (inutiles pour les arbres)
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PRUNE_VARIANCE_THRESHOLD = float(os.getenv('PRUNE_VARIANCE_THRESHOLD', '1e-6'))
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feature_variances = X.var()
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low_var_features = feature_variances[feature_variances < PRUNE_VARIANCE_THRESHOLD].index.tolist()
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if low_var_features:
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log_info(f"[{name}] Élagage : {len(low_var_features)} feature(s) à variance < {PRUNE_VARIANCE_THRESHOLD} retirées : {low_var_features}")
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X = X.drop(columns=low_var_features)
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features = [f for f in features if f not in low_var_features]
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log_decision('FEATURE_PRUNED', cycle_id, name, {'pruned': low_var_features, 'remaining': len(features)})
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# Validation split : réserver 20% pour évaluation offline
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val_size = max(1, int(len(X) * 0.2))
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X_train = X.iloc[:-val_size]
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X_val = X.iloc[-val_size:]
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if EIF_AVAILABLE:
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model = ExtendedIsolationForest(
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ntrees=300, ndim=min(3, len(features)),
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sample_size='auto', missing_action='impute',
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random_seed=42, nthreads=-1
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)
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else:
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model = IsolationForest(n_estimators=300, contamination=CONTAMINATION, random_state=42, n_jobs=-1)
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model.fit(X_train)
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# Évaluation offline : score moyen sur la validation (devrait être > 0 pour du trafic humain sklearn)
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val_scores = model.decision_function(X_val)
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# Unifier la convention : négatif = anomal (isotree: 0.5 - score)
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if EIF_AVAILABLE:
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val_scores = 0.5 - val_scores
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val_mean_score = float(np.mean(val_scores))
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val_anomaly_rate = float(np.mean(val_scores < 0))
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log_info(f"[{name}] Validation : score moyen={val_mean_score:.4f}, taux anomalie={val_anomaly_rate:.2%} ({len(X_val)} échantillons)")
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# GATE CONDITION : rejeter le modèle si la baseline semble contaminée
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VAL_ANOMALY_GATE = float(os.getenv('VAL_ANOMALY_GATE', '0.20'))
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if val_anomaly_rate > VAL_ANOMALY_GATE:
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log_info(f"[{name}] ⚠ REJET : val_anomaly_rate={val_anomaly_rate:.2%} > gate={VAL_ANOMALY_GATE:.0%} — baseline probablement contaminée.")
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log_decision('MODEL_REJECTED', cycle_id, name, {
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'val_anomaly_rate': round(val_anomaly_rate, 4), 'gate': VAL_ANOMALY_GATE,
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'val_mean_score': round(val_mean_score, 4), 'version_id': version_id,
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})
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# Tenter de réutiliser le modèle précédent
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if model_path and os.path.exists(model_path):
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log_info(f"[{name}] Conservation du modèle précédent v{meta.get('version_id', '?')}.")
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ae_prev = None
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if TORCH_AVAILABLE and AE_WEIGHT > 0:
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ae_prev_path = _ae_model_path(name, meta.get('version_id', ''))
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if os.path.exists(ae_prev_path):
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try:
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ae_prev = TrafficNormalizingFlow.load_state_dict(torch.load(ae_prev_path, weights_only=False))
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except Exception:
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pass
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return joblib.load(model_path), ae_prev, meta.get('features', features)
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log_info(f"[{name}] Aucun modèle précédent — utilisation du modèle rejeté par défaut.")
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# A1 — Statistiques de référence pour la baseline (mean/std uniquement,
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# la détection de dérive est assurée par ADWIN en temps réel)
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baseline_stats = {
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f: {
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'mean': float(X[f].mean()),
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'std': float(X[f].std()),
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}
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for f in features
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}
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new_model_path = os.path.join(MODEL_DIR, f'model_{name}_{version_id}.joblib')
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new_meta_path = os.path.join(MODEL_DIR, f'model_{name}_{version_id}.meta.json')
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joblib.dump(model, new_model_path)
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# Entraînement du Normalizing Flow en parallèle (si PyTorch disponible et AE_WEIGHT > 0)
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ae_model = None
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if TORCH_AVAILABLE and AE_WEIGHT > 0:
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try:
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ae_model = TrafficNormalizingFlow(n_features=len(features))
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ae_stats = ae_model.fit(X_train.values)
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ae_path = _ae_model_path(name, version_id)
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torch.save(ae_model.state_dict(), ae_path)
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log_info(f"[{name}] Normalizing Flow entraîné : NLL={ae_stats['final_loss']:.6f}, epochs={ae_stats['epochs']}")
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except Exception as exc:
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log_info(f"[{name}] Normalizing Flow training échoué : {exc} — NF désactivé.")
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ae_model = None
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previous_version = meta.get('version_id', None) if meta else None
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new_meta = {
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'version_id': version_id, 'trained_at': datetime.now().isoformat(),
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'human_samples': len(human_baseline), 'contamination': CONTAMINATION,
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'threshold': ANOMALY_THRESHOLD, 'features': features,
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'model_name': name, 'previous_version': previous_version,
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'retrain_interval': RETRAIN_INTERVAL_H, 'baseline_stats': baseline_stats,
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'algorithm': 'ExtendedIsolationForest' if EIF_AVAILABLE else 'IsolationForest',
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'autoencoder': ae_model is not None, # NF en réalité, clé conservée pour rétro-compatibilité
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'ae_weight': AE_WEIGHT if ae_model else 0.0,
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'validation': {
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'val_size': len(X_val), 'train_size': len(X_train),
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'val_mean_score': round(val_mean_score, 4),
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'val_anomaly_rate': round(val_anomaly_rate, 4),
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}
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}
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with open(new_meta_path, 'w') as f: json.dump(new_meta, f, indent=2)
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with open(_current_pointer_path(name), 'w') as f: f.write(version_id)
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append_training_history({k: v for k, v in new_meta.items() if k != 'baseline_stats'})
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_purge_old_versions(name)
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log_info(f"[{name}] Modèle v{version_id} sauvegardé → {new_model_path} (NF={'oui' if ae_model is not None else 'non'})")
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log_decision('MODEL_TRAINED', cycle_id, name, {
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'version_id': version_id, 'previous_version': previous_version,
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'human_samples': len(human_baseline), 'next_retrain_in_h': RETRAIN_INTERVAL_H,
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'history_kept': MODEL_HISTORY_COUNT
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})
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return model, ae_model, features
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