nvalchemi-reporting
How to add observability to nvalchemi dynamics and training workflows using ReportingOrchestrator, RichReporter, TensorBoardReporter, scalar extraction, custom…
npx skills add https://github.com/nvidia/nvalchemi-toolkit --skill nvalchemi-reportingnvalchemi Reporting
Overview
Use reporting for curated workflow summaries and dashboards. Use logging for
direct event records such as per-system dynamics rows. Link agents to
docs/userguide/reporting.md, docs/userguide/training.md,
docs/userguide/dynamics.md, and docs/userguide/hooks.md for full details.
from nvalchemi.hooks import (
ReportingOrchestrator,
RichReporter,
TensorBoardReporter,
)
from nvalchemi.dynamics.hooks import LoggingHook
Choose The Layer
Use ReportingOrchestrator when the user wants progress summaries, live Rich
dashboards, TensorBoard scalar snapshots, rank reductions, or one observability
hook that works across training, dynamics, and custom hook-enabled workflows.
ReportingOrchestrator is the hook to register with hooks=[...] or
register_hook(...); RichReporter, TensorBoardReporter, and custom
Reporter objects are sinks owned by that hook and are not registered directly.
Workflow engines enter and close hook context managers automatically during
run(), so user code should not wrap reporting hooks manually in normal cases.
Use nvalchemi.dynamics.hooks.LoggingHook when the user wants a durable
per-graph dynamics event stream. It computes dynamics observables such as
energy, fmax, temperature, status, and graph index, then writes one row per
system to CSV, TensorBoard, or a custom writer.
Do not reuse the dynamics LoggingHook as a training logger. For training,
prefer reporters unless the task explicitly requires a raw training-event log;
then implement a training-specific hook with the same hook protocol.
Training Pattern
Attach the ReportingOrchestrator as a normal training hook. Pick stages by
enum name when the code already serializes hook specs or when avoiding imports
in config files. Use AFTER_OPTIMIZER_STEP for high-frequency loss and
learning-rate progress, and validation stages when summaries should align with
validation output.
from nvalchemi.hooks import ReportingOrchestrator, RichReporter, TensorBoardReporter
from nvalchemi.training import CheckpointHook, TrainingStrategy
reporting = ReportingOrchestrator(
[
TensorBoardReporter("runs/example/tensorboard"),
RichReporter(layout="training", refresh_per_second=2.0),
],
stages={"AFTER_OPTIMIZER_STEP"},
frequency=10,
)
strategy = TrainingStrategy(
models=model,
optimizer_configs=optimizer_config,
loss_fn=loss_fn,
hooks=[
reporting,
CheckpointHook("runs/example/checkpoints", epoch_interval=1),
],
num_epochs=20,
)
strategy.run(train_loader)
Guidelines:
- Register reporting through
hooks=[reporting];strategy.run(...)enters and closes the reporting hook automatically. - Keep checkpoints and reporting separate; reporters observe, checkpoint hooks preserve restart state.
- Use
RichReporter(layout="training")for terminal monitoring during local or interactive runs. - Use
TensorBoardReporter(...)for durable scalar summaries and later review. - Set
frequencyhigh enough to avoid excessive terminal refresh or file I/O on large distributed runs. - Add custom scalar callbacks when a metric is not already exposed through loss, optimizer, scheduler, validation, or workflow context.
Dynamics Pattern
For live summaries or TensorBoard dashboards, use ReportingOrchestrator with a
dynamics layout. The dynamics Rich layout asks the reporter to collect default
dynamics scalars such as energy, fmax, temperature, convergence fraction,
active count, graduated count, and status counts when available.
from nvalchemi.dynamics import DynamicsStage, NVE
from nvalchemi.hooks import ReportingOrchestrator, RichReporter
reporting = ReportingOrchestrator(
[RichReporter(layout="dynamics", refresh_per_second=2.0)],
stages={DynamicsStage.AFTER_STEP},
frequency=25,
)
dynamics = NVE(
model=model,
dt=0.5,
n_steps=10_000,
hooks=[reporting],
)
final_batch = dynamics.run(batch)
For a durable per-system trajectory-adjacent log, add LoggingHook instead of
or in addition to reporting:
from nvalchemi.dynamics import DynamicsStage, NVTLangevin
from nvalchemi.dynamics.hooks import LoggingHook
logger = LoggingHook(
backend="csv",
log_path="runs/md/scalars.csv",
frequency=100,
stage=DynamicsStage.AFTER_STEP,
)
dynamics = NVTLangevin(
model=model,
dt=0.5,
temperature=300.0,
n_steps=50_000,
hooks=[logger],
)
final_batch = dynamics.run(batch)
Guidelines:
- Register reporting or logging through
hooks=[...]; dynamicsrun(...)enters and closes hook context managers automatically. - Use reporting for dashboards and scalar summaries; use
SnapshotHookor data sinks for full batch states and trajectories. - Use
LoggingHook(backend="custom", writer_fn=...)when rows should go tologuru, a database, or a user-owned writer. - Give each distributed rank a unique
log_pathwhen using dynamicsLoggingHook; it writes directly and does not coordinate file access. - Attach observation hooks at
DynamicsStage.AFTER_STEPunless the metric needs a more specific stage.
Distributed Reporting
Reporters can be rank-gated. Defaults are conservative for terminal and file outputs: rank zero writes or renders unless a reporter requires all ranks for a collective reduction.
reporting = ReportingOrchestrator(
[
RichReporter(
layout="training",
rank_reduction="mean",
rank_zero_only=True,
),
TensorBoardReporter("runs/ddp/tensorboard", rank_zero_only=True),
],
stages={"AFTER_OPTIMIZER_STEP"},
frequency=20,
)
Guidelines:
- Use
rank_reduction="mean"for loss curves in DDP when every rank reports matching scalar keys. - Ensure every rank reaches reporters that perform reductions; do not add local control flow that skips nonzero ranks before the collective.
- Use rank-specific paths such as
"runs/ddp/rank-{rank}"only when every rank intentionally writes its own artifact. - Keep Rich dashboards rank-zero-only for normal terminal runs.
Custom Scalars
Pass custom_scalars to reporters when metrics are present in the context or
batch but are not part of the default extraction path. Return plain numbers or
scalar tensors; keep callbacks cheap because they run at reporting frequency.
def grad_norm(ctx):
total = 0.0
for parameter in ctx.model.parameters():
if parameter.grad is not None:
total += float(parameter.grad.detach().norm().item())
return total
reporting = ReportingOrchestrator(
[
RichReporter(custom_scalars={"optimizer/grad_norm": grad_norm}),
TensorBoardReporter(
"runs/example/tensorboard",
custom_scalars={"optimizer/grad_norm": grad_norm},
),
],
stages={"AFTER_OPTIMIZER_STEP"},
frequency=25,
)
For dynamics LoggingHook, callbacks receive DynamicsContext and must return
either a per-graph tensor with shape (B,) or a scalar that can be broadcast to
all graphs:
logger = LoggingHook(
backend="csv",
log_path="runs/md/scalars.csv",
custom_scalars={
"max_velocity": lambda ctx: ctx.batch.velocities.norm(dim=-1).max(),
},
frequency=100,
)
Rich Dashboard Workflows
Use RichReporter.preview(...) when choosing or checking a dashboard surface
without running a real workflow:
from nvalchemi.hooks import RichReporter
RichReporter.preview(layout="training", title="training preview")
RichReporter.preview(layout="dynamics", title="dynamics preview")
Use BaseRichLayout for custom table-plus-plot dashboards. Implement the
RichLayout protocol directly only when the output needs a custom Rich
renderable. Do not create a nested rich.live.Live; RichReporter owns the
console, lifecycle, refresh rate, history, and rank filtering.
Agent Checklist
- Add observability by default for long-running examples, CLI scaffolds, fine-tuning scripts, DDP jobs, and dynamics simulations.
- Prefer
ReportingOrchestrator([RichReporter(...), TensorBoardReporter(...)])for training progress. - Add
LoggingHook(backend="csv", ...)for dynamics runs that need analyzable per-system rows. - Register
ReportingOrchestratoras the hook; letTrainingStrategy.run()and dynamicsrun()enter and close hook context managers automatically. - Do not ask users to wrap reporters or dynamics
LoggingHookmanually unless they are invoking hook calls outside a workflow engine. - Avoid expensive scalar callbacks and
.item()calls inside hot training code unless they run at a controlled reporting frequency. - Mention generated output paths in examples and tests so users know where to inspect CSV, TensorBoard, checkpoints, and dashboards.