Replace discovery flooding with bloom-filter-guided tree routing:
lookups sent only to tree peers (parent + children) whose bloom
filter contains the target. If no tree peer matches, fall back to
non-tree peers with bloom matches before dropping the request. This
produces single-path forwarding through the spanning tree (90%
traffic reduction) while recovering from dead ends caused by stale
bloom filters, tree restructuring, or transit node failures.
Remove visited bloom filter from LookupRequest wire format (-257
bytes per request). Tree routing is inherently loop-free; request_id
dedup handles edge cases during tree restructuring. Add response-
forwarded flag to prevent response routing loops from convergent
request paths.
Add originator-side exponential backoff (30s base, 300s cap) after
lookup timeouts and bloom misses. Backoff resets on topology changes
(parent switch, new peer, first RTT, reconnection).
Add transit-side per-target rate limiting (2s minimum interval) for
forwarded lookups as defense-in-depth.
Add discovery retry within the timeout window (default: send at T=0,
retry at T=5s, fail at T=10s) to compensate for single-path fragility.
Lookups with zero eligible tree peers fail immediately.
Improve discovery logging: promote key events to info (initiation,
success, timeout with failure count). Add debug logging for dedup,
pending packet retry, backoff suppression, forward rate limiting,
and backoff reset.
New config: discovery.backoff_base_secs, backoff_max_secs,
forward_min_interval_secs, retry_interval_secs, max_attempts.
New stats: req_backoff_suppressed, req_forward_rate_limited,
req_bloom_miss, req_no_tree_peer, req_fallback_forwarded.
Removed: req_already_visited, visited bloom filter.
Three infrastructure bugs fixed:
- DNS resolution never populated the identity cache because Docker
overwrites /etc/resolv.conf at container start. Fix: bind-mount
resolv.conf in the chaos compose template, matching the static and
sidecar test configs.
- Traffic generator used config-time npubs for iperf3 targets, but
ephemeral nodes generate fresh keypairs at startup. Fix: share the
peer churn manager's runtime npub cache with the traffic manager.
- Log analysis had no discovery counters and used wrong patterns.
Fix: add discovery section with correct log message matching.
Also adds timestamped output directories (YYYYMMDD-HHMMSS-scenario),
coord_ttl_secs override in maelstrom.yaml, FIPS_SIM_OUTPUT env var
support, and maelstrom-sparse scenario for sparse topology testing.
Johnathan Corgan