6cdfbff8d6
Adds the convergence guardrail: every per-epoch HEALTH_DIAG metric is
checked against the bands in config/metric-bands.toml; N consecutive
warn-band epochs emit a tracing::warn; 2N consecutive error-band epochs
return Err(CommonError::RegressionDetected{...}) cleanly from the
training loop, which propagates to the train_baseline_rl subprocess
exit code (no libc::raise — clean Rust error path).
Wire-points:
- New module: crates/ml/src/trainers/dqn/trainer/monitoring.rs
- MetricBands {warn_low, warn_high, error_low, error_high}
- BandSettings {consecutive_epochs_for_warn, consecutive_epochs_for_error}
- MetricBandsRegistry: load_from_toml + update_and_check
- TerminationReason {RegressionWarn, RegressionError}
- NaN treated as out-of-band (consecutive++; never resets streak)
- Unknown metrics return None (silent OK per Invariant 7 audit)
- crates/common/src/error.rs: new CommonError::RegressionDetected variant
carrying {metric, value, band, consecutive}
- crates/ml/src/trainers/dqn/trainer/constructor.rs: load
config/metric-bands.toml at trainer init; warn-only on missing file
(backward compat for environments without the config)
- crates/ml/src/trainers/dqn/trainer/training_loop.rs: harvest per-epoch
metrics (parallel emit alongside HEALTH_DIAG), feed each through
registry.update_and_check; on Some(TerminationReason::RegressionError)
emit final HEALTH_DIAG[N]: TERMINATED_BY_REGRESSION line and return Err
- services/trading_service/src/error.rs: minimal handler for the new
CommonError variant (existing pattern)
Validation:
- 8 unit tests in monitoring::tests pass (band logic, NaN, warn-only
behaviour, error-streak threshold, unknown-metric, invalid TOML)
- regression_detection GPU smoke (3.19s): trainer with intentionally
narrow train_loss error band [0, 1e-9] self-terminates at epoch 5
after 6 consecutive error-band epochs; final HEALTH_DIAG line emits
TERMINATED_BY_REGRESSION with metric/value/consecutive/band fields
- multi_fold_convergence smoke (650s, --release): all 3 folds train
to completion, all 3 checkpoints saved, no false-positive
termination on the populated metric bands. Per-fold best train
Sharpe: F0=-9.7831 (bit-baseline), F1=25.8272, F2=39.2687. F1/F2
on the lower end of observed noise distribution
({74.56, 61.10, 71.53, 25.83} for F1; {88.20, 61.57, 65.96, 39.27}
for F2) but training healthy throughout: aux clauses fire every
epoch, sharpe_ema recovers from F0 collapse (-9.78 → +14.8 by start
of F2), no regression detection trips.
config/metric-bands.toml populated for the metrics emitted by
HEALTH_DIAG today (avg_q_value, train_loss, val_sharpe, train_sharpe,
aux_next_bar_mse, aux_regime_ce, isv_* slot EMAs, sharpe_ema, etc.).
Bands derived from current cleanroom smoke + permissive defaults
where only one sample exists; populate-metric-bands-from-runs.py will
tighten them after Plan 5 Task 5's multi-seed pass produces real
distributions.
Constraints honoured: GPU-only in hot path (band check is CPU-side
post-HEALTH_DIAG, off the captured graph); no atomicAdd; no stubs;
no // ok: band-aids; no tuned constants beyond the toml-loaded bands;
no .unwrap() introduced; cargo check clean at 11 warnings (workspace
baseline preserved, plus ml-dqn pre-existing 1 warning).
Audit doc: new row added documenting monitoring.rs module, the
CommonError variant, the training_loop wire-point, and the design
choice that band-checks run AFTER HEALTH_DIAG emit (not before) so
the diag log already reflects the metric values that triggered any
termination.
Plan 5 T1 (multi-seed harness) landed at c6634254e+47c8b783c; T2
(this) gives the regression hard-stop that the multi-seed final
pass (T5) consumes to bail out early on bad seeds.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
common
Shared types, error handling, and utilities for the Foxhunt HFT ecosystem.
Key Types
FoxhuntError— unified error enum withResultaliasModelType— canonical ML model enum (10 primary variants)CircuitBreakerTrait— async circuit breaker interfaceTlsProtocolVersion,ClientIdentity— TLS configuration types- Market data types (
Tick,OrderBook) and order types (LimitOrder,MarketOrder)
Modules
model_types— canonicalModelTypeenum re-exported by ml/ and model_loader/resilience—CircuitBreakerTraitasync traittls— TLS types and configurationquestdb— QuestDB client configuration
Usage
use common::{FoxhuntError, ModelType};