Files
Rohit Ghumare d1517465ca feat(bench): load-100k.ts harness with p50/p90/p99 output (#363)
Adds a reproducible, dependency-free load harness so we can answer
"what's p99 at 100k memories under concurrency 100?" with a number
instead of a shrug.

The harness seeds N synthetic memories against a local agentmemory
daemon (defaults to http://localhost:3111, optional autostart via
AGENTMEMORY_BENCH_AUTOSTART=1), then drives a matrix of
(N, concurrency, endpoint) cells with hand-rolled Promise.allSettled
batches. Per-request latency is collected via performance.now() and
summarized as nearest-rank p50 / p90 / p99 plus min / max / errors
and wall-clock throughput. Results are written to
benchmark/results/load-100k-<short-git-sha>.json with a
schema_version field so future format changes don't silently break
consumers.

Defaults match issue #346: N in {1000, 10000, 100000} x C in
{1, 10, 100} x three endpoints (POST /agentmemory/remember,
POST /agentmemory/smart-search, GET /agentmemory/memories?latest=true).
Each cell issues BENCH_OPS=200 requests by default — enough samples
for stable p99 without dragging a 100k-seed run past tens of minutes.

Content is generated by a small noun/verb/concept vocabulary fed by a
mulberry32(BENCH_SEED) PRNG so re-running the harness against the
same daemon build yields the same seed corpus. Reproducibility, not
realism, is the point — latency variance comes from the daemon, not
JSON payload jitter.

Files:
- benchmark/load-100k.ts: main harness
- benchmark/lib/percentiles.ts: zero-dep pXX helper, nearest-rank
- benchmark/README.md: how to run, what gets measured, where results
  land, and why p99 is the number you want for capacity planning
- benchmark/results/load-100k-96c0ed0.json: example result from a
  small-N (N=1000, C=10) verification run against a fresh daemon
- package.json: wires `npm run bench:load`
- CHANGELOG.md: Unreleased entry + a Performance section placeholder
  describing where per-release numbers should land going forward

Verified locally at BENCH_N=1000 BENCH_C=10 BENCH_OPS=200 — three
cells, zero errors, JSON written. Full 100k matrix is intentionally
deferred to CI/release time. Closes #346.
2026-05-13 21:06:43 +01:00
..

benchmark/

Two kinds of numbers live in this directory:

  1. Quality / retrieval — longmemeval-bench.ts, quality-eval.ts, real-embeddings-eval.ts, scale-eval.ts. Recall, precision, token savings. Documented in LONGMEMEVAL.md, QUALITY.md, REAL-EMBEDDINGS.md, SCALE.md.

  2. Load shape — load-100k.ts. p50 / p90 / p99 latency and throughput against a running daemon. This is the file you want when somebody asks "what's p99 at 100k memories under concurrency 100?".

load-100k.ts

Hand-rolled, dependency-free load harness. Issues real HTTP against a local agentmemory daemon at http://localhost:3111, records per-request latency with performance.now(), and writes a JSON report per run.

What it measures

For each cell in the matrix (N, concurrency, endpoint) it records:

  • p50_ms, p90_ms, p99_ms — nearest-rank percentiles.
  • min_ms, max_ms, ops, errors.
  • throughput_per_sec — wall-clock ops / sec for that cell.

Default matrix:

  • N ∈ {1000, 10000, 100000} — number of memories seeded before the cell runs.
  • C ∈ {1, 10, 100} — concurrent in-flight requests during the cell.
  • Endpoints under test:
    • POST /agentmemory/remember
    • POST /agentmemory/smart-search
    • GET /agentmemory/memories?latest=true

Each cell issues BENCH_OPS=200 requests by default — enough samples for stable p99 without dragging a 100k-seed run past tens of minutes.

Why p99 is the number that matters

p50 tells you the median request feels fast. p90 tells you the bulk of requests feel fast. p99 tells you the request your tail user hits when they really need it feels fast. Capacity planning lives here — if you want to size a fleet, scale your daemon, or set an SLO, p99 is the number to plan against. p50 will lie to you.

Running it

# 1. Start the daemon however you normally do (npx, Docker, etc.)
npx @agentmemory/agentmemory

# 2. From the repo root, in another shell:
npm run bench:load

To override the matrix:

BENCH_N=1000 BENCH_C=1,10 BENCH_OPS=100 npm run bench:load

To have the harness spawn a daemon for the run (after npm run build):

AGENTMEMORY_BENCH_AUTOSTART=1 npm run bench:load

Other env knobs (see the file header for the canonical list):

  • AGENTMEMORY_URL — base URL of the daemon (default http://localhost:3111).
  • BENCH_SEED — seed for the mulberry32 content RNG. Same seed + same daemon build = byte-identical seed corpus.
  • BENCH_OUT_DIR — where the JSON report lands (default benchmark/results/).

Where results land

benchmark/results/load-100k-<short-git-sha>.json. The harness mkdir -ps the directory. The file has a schema_version: 1 field so future format changes don't silently break consumers.

Content generation is seedable

Synthetic memory content is built from a small noun / verb / concept vocabulary fed by a mulberry32(BENCH_SEED) PRNG. Same seed + same build = same corpus. The point isn't "realistic" content (there isn't one realistic content); the point is reproducibility — re-running the harness against the same git sha should give the same content mixture going in, so latency variance comes from the daemon and not from JSON payload jitter.

Publishing numbers per release

The release flow appends a ## Performance section to CHANGELOG.md referencing the JSON in benchmark/results/ for that release's git sha. p99 is the headline number; the JSON is the receipt.