shoney.arickathil
f4794fc235
- bench/baseline.json: 74 metrics from the first full campaign; tolerances tuned by a two-run repeatability check (mix* 50%, read/query 35%, rest 15% — rationale in _config) - gate bites: --check mode; doctored copy fails, both real runs 74/0 - headline: durable seed 4.5k/s vs ram 297k/s (23's case); reads O(table) at ~1.5k/s; mixread 1280 vs 21 ops/s single-vs-multi (the arc's price); msgrate 13.4M vs 2.45M (mutex-inbox number) - arc delta recorded in story 8; findings in sample README Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> |
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| .. | ||
| main.wo | ||
| README.md | ||
| types.wo | ||
| wo.toml | ||
db-bench — iteration 22's load generator
The measurement backbone (spec:
docs/superpowers/specs/2026-08-21-db-bench-design.md). Pure .wo;
every measured mode prints one machine-parsable line per operation
class:
<op> <count> <ops/sec> <p50us> <p99us>
Timing is per-operation via time.ticks (CLOCK_MONOTONIC µs).
Percentiles come from a 1µs-bucket histogram clamped at 20000µs — exact
to the microsecond below the clamp; a p99 AT 20000 means "clamp or
worse". (A histogram, not the spec's reservoir: the language has no
container element-write or sort, and the histogram's tail fidelity is
strictly better. Recorded as a plan deviation.)
Modes
| mode | what it prices |
|---|---|
all N |
the throughput campaign in ONE process: seed N, read N/2, query N/10, write N/2. Without WO_DATA the store is RAM and dies with the process, so the measured modes must share the seeding run. |
seed N |
timed inserts: one parent per 100 children (FK probe each insert, unique-index maintenance per parent), k non-unique (10 rows/key), deterministic v. Writes Meta expectation rows. |
read N |
indexed take-1 point lookups, LCG-spread keys. |
query N |
full equality probes on the k index (≈10 rows each), materialized and counted. |
write N |
alternating inserts (disjoint k range 2e6+) and updates through query results. Corrupts the checksum by design — durability legs run on a fresh store. |
wal N |
the crash battery's vehicle: insert-only (k range 1e6+), acked <i> printed AFTER each insert returns — the return IS the ack (RAM applied, WAL record staged, ONE commit done). |
verify |
store vs its own Meta rows: count, checksum, one unique probe. Exit 3 on mismatch. |
verify-acked M |
after kill -9 mid-wal: rows 1..M exist with the right v; rows beyond M allowed (acked after the last print flushed). Exit 3 on mismatch. |
Coordination idiom (this side of iteration 31)
There is no request/response surface yet: concurrent modes drive completion the db-actor way — actors write rows, main polls the store until the expected count, then settles. Retired when 31 lands.
Standing finding (2026-08-21, first run)
A hand-built multi Bucket of insert results SEGVs on drop: the
compiler classifies the elements OWNED while table refs are scalar ids.
Query-built multis are runtime-typed and safe. Worked around here
(single ref local, bucket-major seeding); the compiler fix is its own
slice.
Reference-machine numbers (first campaign, 2026-08-21)
bench/baseline.json is the contract; headline readings:
- ram seed 257–298k inserts/s; durable seed ≈4.5k/s (fsync-per-commit ≈220µs each — the gap iteration 23 exists to close).
- reads ≈1.5k/s at p50 ≈600µs on a 20k-row store: point lookups are O(table) — the probe walks every slab; index selection never reaches the lookup path. THE read-path finding.
- mixread 1,280 ops/s single-shard vs 21 ops/s multi-shard: RPC round-trip × O(table) probes × owner serialization — the arc's honest price until reads index properly.
- msgrate 13.4M msgs/s same-heap vs 2.45M cross-shard (the mutex-inbox number, stage-2 deviation 4).
The gate must bite (proven 2026-08-21)
scripts/db-bench.py --check <results.json> evaluates a recorded run:
the real results pass 74/0; a doctored copy (one ops/sec halved) FAILS
on exactly that metric. Re-run the smoke after any gate change.