Files
Johnathan Corgan 5d3a3d7cad Give the assertion-free chaos scenarios a convergence floor
Five scenarios named by the audit carried no assertions at all, so a run
in which the mesh never formed exited 0 and reported green. Add a
baseline assertion covering how many nodes answered, how many distinct
roots they agreed on, how many took a parent, and optionally how many
sessions were established, and apply it to those five plus the two cost
scenarios left unasserted by the previous commit.

For ethernet-only, ethernet-mesh, tcp-mesh, smoke-10, mixed-technology
and depth-vs-cost the values are not calibrated: one root and N-1
parented nodes is what a spanning tree is, and all provably-completed
archived runs of each show exactly that. churn-mixed is different and
says so at the site. A scenario that stops and starts nodes on purpose
does not hold a single tree, and its six completed runs end with two or
three roots and seven or eight of ten nodes parented, so its floors sit
one step outside the observed range. That leaves them catching a mesh
that collapsed rather than one that churned, which is the most a sample
of six supports.

This gives Ethernet transport its only assertion anywhere in CI. The
three tests in src/node/tests/ethernet.rs are ignored for requiring
CAP_NET_RAW and neither runner passes --ignored, so until now nothing
exercised that transport with a verdict attached.

The floor is deliberately weak and deliberately not a substitute: it says
the mesh formed, not that it formed the tree the scenario describes.
Where those differ the scenario now says so in its own comments.
2026-07-23 07:09:36 +00:00

445 lines
15 KiB
Python

"""Post-run scenario assertions evaluated via control-socket data.
Assertions are declared in the scenario YAML under ``assertions:`` and
are evaluated near the end of the simulation, before teardown begins.
Each failing assertion is recorded with a clear pass/fail message; the
runner exits non-zero when any assertion fails.
Currently supported assertions:
- ``bloom_send_rate``: per-node trailing-window ceiling on
``stats.bloom.sent`` delta. Calibrated for the bloom-storm
regression scenario but generally usable.
"""
from __future__ import annotations
import logging
from dataclasses import dataclass
from .control import snapshot_all_bloom
from .scenario import (
BaselineAssertion,
BloomSendRateAssertion,
CongestionSignalsAssertion,
MaxErrorsAssertion,
MaxParentSwitchesAssertion,
MinParentSwitchesAssertion,
TreeParentsAssertion,
)
from .topology import SimTopology
log = logging.getLogger(__name__)
@dataclass
class AssertionOutcome:
name: str
passed: bool
detail: str
def _bloom_sent_total(node_data: dict) -> int | None:
"""Extract stats.bloom.sent from a show_bloom response."""
stats = node_data.get("stats") or {}
sent = stats.get("sent")
if sent is None:
return None
try:
return int(sent)
except (TypeError, ValueError):
return None
class BloomSendRateMonitor:
"""Samples per-node ``stats.bloom.sent`` to evaluate a trailing-window
ceiling assertion at end-of-run.
Usage:
m = BloomSendRateMonitor(topology, cfg)
m.sample_window_start() # called window_secs before scenario end
...
m.sample_end() # called at scenario end
outcome = m.evaluate()
"""
def __init__(self, topology: SimTopology, cfg: BloomSendRateAssertion):
self.topology = topology
self.cfg = cfg
self.window_start: dict[str, int] = {}
self.window_end: dict[str, int] = {}
def sample_window_start(self) -> None:
snap = snapshot_all_bloom(self.topology)
for nid, data in snap.items():
v = _bloom_sent_total(data)
if v is not None:
self.window_start[nid] = v
def sample_end(self) -> None:
snap = snapshot_all_bloom(self.topology)
for nid, data in snap.items():
v = _bloom_sent_total(data)
if v is not None:
self.window_end[nid] = v
def evaluate(self) -> AssertionOutcome:
max_per_node = self.cfg.max_per_node
window_secs = self.cfg.window_secs
if not self.window_start or not self.window_end:
return AssertionOutcome(
name="bloom_send_rate",
passed=False,
detail=(
f"FAIL bloom_send_rate: failed to sample window endpoints "
f"(start={len(self.window_start)} nodes, "
f"end={len(self.window_end)} nodes)"
),
)
per_node_deltas: dict[str, int] = {}
for nid, end_v in self.window_end.items():
start_v = self.window_start.get(nid)
if start_v is None:
continue
per_node_deltas[nid] = end_v - start_v
offenders = {
nid: d for nid, d in per_node_deltas.items() if d > max_per_node
}
max_obs = max(per_node_deltas.values()) if per_node_deltas else 0
if offenders:
sorted_off = sorted(offenders.items(), key=lambda kv: -kv[1])
details = ", ".join(f"{nid}={d}" for nid, d in sorted_off)
detail = (
f"FAIL bloom_send_rate: {len(offenders)} node(s) exceeded "
f"ceiling of {max_per_node} bloom_sent over trailing "
f"{window_secs}s — offenders: {details} "
f"(all per-node deltas: "
f"{', '.join(f'{n}={v}' for n, v in sorted(per_node_deltas.items()))})"
)
return AssertionOutcome(
name="bloom_send_rate",
passed=False,
detail=detail,
)
detail = (
f"PASS bloom_send_rate: max per-node delta {max_obs} <= "
f"ceiling {max_per_node} over trailing {window_secs}s "
f"(per-node: "
f"{', '.join(f'{n}={v}' for n, v in sorted(per_node_deltas.items()))})"
)
return AssertionOutcome(
name="bloom_send_rate",
passed=True,
detail=detail,
)
def evaluate_max_parent_switches(
cfg: MaxParentSwitchesAssertion,
parent_switch_count: int,
scope: str,
) -> AssertionOutcome:
"""Stability ceiling on parent switches over the run.
``scope`` describes what was counted and appears in the message, so a
reader can tell a per-node result from a mesh-wide one. Resolving a
per-node scope to a real node is the caller's job, and so is failing
loudly when it cannot: an unresolvable node would count zero switches
and sail under any ceiling without having observed anything.
"""
if parent_switch_count <= cfg.max_total:
return AssertionOutcome(
name="max_parent_switches",
passed=True,
detail=(
f"PASS max_parent_switches: {parent_switch_count} switches "
f"({scope}) <= ceiling {cfg.max_total}"
),
)
return AssertionOutcome(
name="max_parent_switches",
passed=False,
detail=(
f"FAIL max_parent_switches: {parent_switch_count} switches "
f"({scope}) > ceiling {cfg.max_total} — the tree is reparenting "
f"more than the hysteresis band should allow. Check whether a "
f"cost change smaller than the hysteresis margin is still "
f"triggering a switch."
),
)
def evaluate_baseline(
cfg: BaselineAssertion,
snapshot: dict | None,
sessions: int,
) -> AssertionOutcome:
"""Floor on the mesh having formed: nodes answered, agreed a root, took parents."""
if not snapshot:
return AssertionOutcome(
name="baseline",
passed=False,
detail=(
"FAIL baseline: no final tree snapshot was taken, so nothing "
"about the mesh was observed. This is a harness failure."
),
)
reporting = len(snapshot)
roots = {v.get("root") for v in snapshot.values() if v.get("root")}
parented = sum(
1 for v in snapshot.values()
if v.get("parent") and v.get("parent") != v.get("my_node_addr")
)
parts, failures = [], []
def note(ok, text):
parts.append(text)
if not ok:
failures.append(text)
if cfg.min_nodes_reporting is not None:
note(reporting >= cfg.min_nodes_reporting,
f"{reporting} node(s) answered (need {cfg.min_nodes_reporting})")
if cfg.max_roots is not None:
note(len(roots) <= cfg.max_roots and len(roots) >= 1,
f"{len(roots)} distinct root(s) (allowed {cfg.max_roots})")
if cfg.min_nodes_parented is not None:
note(parented >= cfg.min_nodes_parented,
f"{parented} node(s) have a parent (need {cfg.min_nodes_parented})")
if cfg.min_sessions is not None:
note(sessions >= cfg.min_sessions,
f"{sessions} session(s) established (need {cfg.min_sessions})")
summary = "; ".join(parts)
if failures:
return AssertionOutcome(
name="baseline",
passed=False,
detail=(
f"FAIL baseline: {'; '.join(failures)}. Full: {summary}"
),
)
return AssertionOutcome(
name="baseline", passed=True, detail=f"PASS baseline: {summary}"
)
def evaluate_tree_parents(
cfg: TreeParentsAssertion,
snapshot: dict | None,
) -> AssertionOutcome:
"""Check each node's parent in the final tree snapshot.
Parents are compared by node address, resolved from the snapshot's own
``my_node_addr`` fields, so the check does not depend on the display
name a node happened to publish.
Every way of not knowing the answer is a failure: no snapshot, the
node absent from it, the expected parent absent from it, or the node
still claiming to be its own root. Each of those produces the same
"no match" that a genuinely wrong parent does, and only saying so
separately keeps a harness problem from reading as a routing verdict.
"""
if not snapshot:
return AssertionOutcome(
name="tree_parents",
passed=False,
detail=(
"FAIL tree_parents: no final tree snapshot was taken, so no "
"node's parent was observed. This is a harness failure, not "
"a statement about the tree."
),
)
addr_of = {
nid: data.get("my_node_addr")
for nid, data in snapshot.items()
if data.get("my_node_addr")
}
id_of = {addr: nid for nid, addr in addr_of.items()}
good, bad = [], []
for child, want_parent in sorted(cfg.expected.items()):
entry = snapshot.get(child)
if entry is None:
bad.append(
f"{child} is absent from the snapshot ({len(snapshot)} node(s) "
f"present: {', '.join(sorted(snapshot))})"
)
continue
want_addr = addr_of.get(want_parent)
if want_addr is None:
bad.append(
f"{child}: expected parent {want_parent} is absent from the "
f"snapshot, so its address cannot be resolved"
)
continue
got_addr = entry.get("parent")
if got_addr == entry.get("my_node_addr"):
bad.append(
f"{child} is its own parent — it still believes it is root, "
f"so the tree never converged around it (wanted {want_parent})"
)
continue
if got_addr == want_addr:
good.append(f"{child}->{want_parent}")
continue
got_id = id_of.get(got_addr) or entry.get("parent_display_name") or got_addr
bad.append(f"{child} chose {got_id}, wanted {want_parent}")
if bad:
detail = f"FAIL tree_parents: {'; '.join(bad)}"
if good:
detail += f". Correct: {', '.join(good)}"
return AssertionOutcome(name="tree_parents", passed=False, detail=detail)
return AssertionOutcome(
name="tree_parents",
passed=True,
detail=f"PASS tree_parents: {', '.join(good)}",
)
_CONGESTION_FLOORS = (
("min_nodes_detected", "congestion_detected"),
("min_nodes_ce_forwarded", "ce_forwarded"),
("min_nodes_ce_received", "ce_received"),
)
def evaluate_congestion_signals(
cfg: CongestionSignalsAssertion,
snapshot: dict | None,
) -> AssertionOutcome:
"""Floors on how many nodes observed each congestion counter.
``snapshot`` is the final congestion snapshot keyed by node id. None
means the snapshot never ran, which fails: a missing snapshot and a
mesh that observed no congestion produce the same zero counts, and
treating them alike is how an assertion comes to pass on an absence
of evidence.
"""
if not snapshot:
return AssertionOutcome(
name="congestion_signals",
passed=False,
detail=(
"FAIL congestion_signals: no final congestion snapshot was "
"taken, so no node was observed at all. This is a harness "
"failure, not a statement about congestion."
),
)
parts, failures = [], []
for attr, counter in _CONGESTION_FLOORS:
floor = getattr(cfg, attr)
if floor is None:
continue
hits = sorted(
nid for nid, data in snapshot.items()
if (data.get("congestion") or {}).get(counter, 0) > 0
)
parts.append(f"{counter}: {len(hits)} node(s) >0 (floor {floor})")
if len(hits) < floor:
failures.append(
f"{counter} non-zero on {len(hits)} node(s), need {floor}"
)
else:
parts[-1] += f" [{', '.join(hits)}]"
summary = "; ".join(parts)
if failures:
return AssertionOutcome(
name="congestion_signals",
passed=False,
detail=(
f"FAIL congestion_signals: {'; '.join(failures)} — across "
f"{len(snapshot)} node(s) sampled. Full counts: {summary}"
),
)
return AssertionOutcome(
name="congestion_signals",
passed=True,
detail=f"PASS congestion_signals: {summary}",
)
def evaluate_max_errors(
cfg: MaxErrorsAssertion,
errors: list[tuple[str, str]],
) -> AssertionOutcome:
"""Ceiling on ERROR-level log lines across the whole mesh.
``errors`` is the ``AnalysisResult.errors`` list of ``(source, line)``
pairs rather than a bare count, so a failure can name the nodes and
quote the lines. A ceiling breach that only reports a number sends the
reader back to the logs it was supposed to save them reading.
"""
count = len(errors)
if count <= cfg.max_total:
return AssertionOutcome(
name="max_errors",
passed=True,
detail=(
f"PASS max_errors: {count} ERROR line(s) mesh-wide <= "
f"ceiling {cfg.max_total}"
),
)
per_node: dict[str, int] = {}
for source, _line in errors:
per_node[source] = per_node.get(source, 0) + 1
worst = sorted(per_node.items(), key=lambda kv: -kv[1])
breakdown = ", ".join(f"{src}={n}" for src, n in worst)
samples = "\n".join(
f" [{src}] {line.strip()}" for src, line in errors[:5]
)
return AssertionOutcome(
name="max_errors",
passed=False,
detail=(
f"FAIL max_errors: {count} ERROR line(s) mesh-wide > ceiling "
f"{cfg.max_total} — per node: {breakdown}. First "
f"{min(5, count)}:\n{samples}"
),
)
def evaluate_min_parent_switches(
cfg: MinParentSwitchesAssertion,
parent_switch_count: int,
) -> AssertionOutcome:
"""Sanity guard: fail the scenario if the harness-induced flap did
not produce at least ``cfg.min_total`` parent switches across the
run. Detects misconfiguration (e.g., wrong root election) where
the bloom-rate assertion would otherwise trivially pass on any
binary including the regressed one.
"""
if parent_switch_count >= cfg.min_total:
return AssertionOutcome(
name="min_parent_switches",
passed=True,
detail=(
f"PASS min_parent_switches: {parent_switch_count} switches "
f"(mesh-wide) >= floor {cfg.min_total}"
),
)
return AssertionOutcome(
name="min_parent_switches",
passed=False,
detail=(
f"FAIL min_parent_switches: {parent_switch_count} switches "
f"(mesh-wide) < floor {cfg.min_total} — harness did not induce "
f"sufficient "
f"parent flapping; bloom-rate assertion would be trivially "
f"true. Check tree-snapshot-warmup.json: did the expected "
f"node win the root election?"
),
)