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