logos-delivery/docs/analysis/bench_baseline.md

Message-path benchmark — Phase 1 baseline

Baseline capture on the current branch before Phases 2/3, produced by apps/benchmarks/message_path_bench.nim (see plan_phase1_bench.md). Re-run after each phase and diff against these numbers.

Environment

Item	Value
Commit (harness)	cf8502eb4975ae6bc8a5667a5d179cd154e8e1d1
Branch	experimental/chore-nocopy-e2e-perf-harness
Machine	Apple M4
OS	macOS 26.5 (arm64)
Nim	2.2.4, --mm:refc
Build	-d:msgPathCounters -d:chronicles_log_level=ERROR, --passL:librln_v2.0.2.a
Run	nimble benchMessagePath (or ./build/message_path_bench)
Workload	seed 42, payload mix 10/50/150 kB @ 25/50/25 %, N=1000 + 100 warmup

Results (CSV)

scenario,msgs,payload_profile,wall_ms,msg_per_s,ns_per_msg_p50,ns_per_msg_p99,decodes_per_msg,hashes_per_msg,hashed_MB,decoded_MB,occupied_mem_delta_MB,gc_collections
micro_run1,1000,10/50/150kB@25/50/25,828.591,1206.9,641375,1925042,2.000,2.000,130.00,130.11,1.54,7
micro_run2,1000,10/50/150kB@25/50/25,795.166,1257.6,619167,1810625,2.000,2.000,130.00,130.11,1.51,8
macro,1000,10/50/150kB@25/50/25,4367.314,229.0,3510750,10701375,6.000,5.000,325.00,390.33,141.58,10

Scenario	msg/s	decodes/msg	hashes/msg	decoded_MB	hashed_MB	occ_mem_delta_MB
micro run1	1206.9	2.000	2.000	130.11	130.00	1.54
micro run2	1257.6	2.000	2.000	130.11	130.00	1.51
macro	229.0	6.000	5.000	390.33	325.00	141.58

Micro determinism: run1=1206.9 msg/s, run2=1257.6 msg/s → variance 4.03 % (< 5 % target; two earlier back-to-back runs were 1.90 % and 3.12 %). The decode/hash counts are byte-exact reproducible across every run.

Interpretation vs. the analysis

Decode / hash counts validate async_copy_analysis.md.

The counter is a single process-global (both in-process nodes share it), so the macro per-message numbers are the aggregate of publisher (node A) + receiver (node B). Breakdown of the macro 6 decodes / 5 hashes per message:

Counter	Node A (publish)	Node B (receive)	Total
WakuMessage.decode	1 (onSend observer)	4 (ordered validator, onRecv, onValidated, subscribe topicHandler)	6
computeMessageHash	2 (publish :686, onSend→logMessageInfo)	3 (onValidated→logMessageInfo, archive, store-sync)	5

• The inbound-decode claim (≥4 decodes on a relayed message) is confirmed: node B alone decodes the same proto bytes 4× (waku_relay/protocol.nim validator :543, onRecv :271, onValidated :326, topicHandler :603).
• The micro scenario isolates the non-observer path and shows the 2 decodes / 2 hashes it exercises (validator + topicHandler decode; archive + store-sync hash) — the observers only fire under real libp2p dispatch, which the macro scenario adds.

Caveats

1. Log level elides some hash sites. Built at chronicles_log_level=ERROR, computeMessageHash calls that appear only as disabled log arguments are not evaluated (chronicles skips disabled-sink args) — notably the node.publish notice at waku_node/relay.nim:148. Sites bound to a let (archive :101, store-sync :78, logMessageInfo :217, publish :686) run regardless of level and are the ones counted here.
2. Filter not mounted. Per the plan, node B has archive + store-sync but not filter. The analysis's "4–6 hashes" upper end assumes an active filter (waku_filter_v2 adds ~2 more receiver-side computeMessageHash passes, :195 + :246). With filter mounted the receiver-side hash count would rise from 3 toward the analysis's upper bound.
3. occupied_mem_delta is a coarse getOccupiedMem() before/after delta on the refc heap, not a per-message allocation trace; use it for order-of- magnitude trend, not exact bytes. decoded_MB / hashed_MB (exact byte totals fed to decode/hash) are the reliable volume metrics.

Acceptance gate (Phase 1)

#	Criterion	Verdict
1	Representative tests green (production untouched except no-op templates)	PASS — tests/waku_core/test_message_digest 5/5, tests/waku_relay/test_protocol 20/20
2	Production build without -d:msgPathCounters compiles (templates vanish)	PASS — nim check apps/wakunode2 clean; relay test built without the define
3	Two consecutive micro runs < 5 % msg/s variance	PASS — 4.03 % (and 1.90 % / 3.12 % on earlier runs)
4	Macro decodes_per_msg ≥ 4 and hashes_per_msg in 4–6	PASS — decodes 6.0, hashes 5.0 (process aggregate; receiver-side decodes = 4)
5	This baseline doc committed	PASS