The simulation exit ladder reported panics and failed assertions but said
nothing about ERROR-level log lines, so a run in which every node errored
on every line still exited 0.
Add a max_errors assertion and apply it to every scenario by default
rather than having each one opt in. This is a floor on what a green run
means rather than a property of an individual scenario, and a scenario
that has to ask for the floor is one that can forget to.
The default ceiling of 0 is what the archived corpus supports: across
2416 result directories no node log contains an ERROR-level line, while
the WARN counter extracted by the same code path ranges from 0 to 1135,
so the counter is known to discriminate rather than merely known to read
zero. A scenario that legitimately induces errors raises the ceiling in
its own YAML and says there why.
Reject rust_log: off alongside it, since that is the one level that would
leave the ceiling counting zero whatever the mesh did.
The scenario's success criterion existed only as a comment: count
"Parent switched" in n04's log, expect at most 5. Nothing read it, and
the scenario declared no assertions at all, so its exit code could only
report that the mesh came up and nothing crashed.
Add a max_parent_switches assertion and wire that criterion to it.
The assertion takes an optional node scope, which is the part that
matters. The existing sibling counts mesh-wide, and a criterion written
about one node's log is a different quantity from the sum over every
node: across archived runs of this scenario n04 is 1 or 2 while the
mesh-wide total ranges 3 to 6. Asserting the sum against a per-node
threshold would check something other than what was specified, and at
this threshold would also have failed several runs that were fine.
Counting nothing must not read as stability. A node id absent from the
topology fails explicitly rather than matching zero log lines and
sailing under the ceiling, and a scenario that declares a parent-switch
assertion while setting a log level that suppresses the events it counts
is rejected at load rather than passing vacuously after a full run. The
parse rejects a mistyped key, a missing, negative, boolean or
non-integer ceiling, and a node written empty or as a non-string -- that
last one because YAML renders a bare `node:` as null, which would
silently revert to the mesh-wide count.
The scenario comment now records what the threshold is worth against
the 11 completed archived runs rather than a single sample: 5 is well
above anything observed, the daemon's own parent hold-down caps
switches near 6 per run, and nearly every switch lands during initial
tree formation before any mutation fires. So this catches only
near-pathological reparenting. Tightening to 3 would make it a real
detector, but that changes the stated criterion rather than fixing it,
so it is left as a decision.
Verified against a live run: the assertion evaluates n04 at 2 against
mesh-wide 4 and passes, and with the ceiling temporarily set to 0 the
scenario exits 3, the assertion-failure code, which it previously could
not reach.
Six-node depth-4 mesh with an induced upstream parent flap. Asserts a
trailing-window ceiling on per-node `stats.bloom.sent` and a sanity
floor on parent-switch count over a ~3-4 min observation window.
Guards against the regression class where a spanning-tree update that
changes only an internal path edge (no root or depth delta) fails to
be properly contained and instead propagates to leaves as a sustained
bloom-traffic oscillation, visible only at fleet scale and only after
several minutes of uptime.
Adds a new chaos primitive (`link_swap`) for deterministic asymmetric
link-cost flapping and a post-run assertion framework with two
checks:
- `bloom_send_rate.max_per_node`: trailing-window ceiling on the
`show_bloom` stats counter delta. Calibrated against the
post-mortem reproduction harness data (per-variant counter table
against pre-fix vs post-fix binaries).
- `min_parent_switches.min_total`: sanity guard against a
misconfigured harness where the flap inducer fires but the
topology never produces a real parent-switch event (e.g., wrong
root election from a different seed). Without this, the
bloom-rate assertion would trivially pass on any binary
including a regressed one.
The runner exits 3 on assertion failure (alongside 0 success and 2
panic-detected). Threshold derivation is documented in the scenario
README; the seed pin is also documented there since smallest-NodeAddr
root election is sensitive to the pubkey hash ordering.
Wired into ci-local.sh's chaos pool and the GitHub CI chaos matrix.
Johnathan Corgan