# Gateway API core additions: unused-feature regression check, 2026-10-15

URL: https://scalws.com/docs/benchmarks/2026-10-15-xeon-gateway-core-regression/
Source: `docs/benchmarks/2026-10-15-xeon-gateway-core-regression.md` in the ScalWS repository

Machine, pinning and method as in `2026-10-14-xeon-ingress-core-regression.md`: 2× Xeon
E5-2650 v2, `performance` governor, turbo off. Server on CPUs 0-3 (4 workers), upstream
and applications on 4-7, `oha` 1.16.0 on 8-15 and 24-31, 64 connections. Daytime run.
The machine was about 8 % slower in absolute terms than on 2026-10-14 (base respond
109 684 against 126 651 req/s), so only the ratios inside this report are meaningful.

Commits: `base` = 273c67e (main before the Gateway API additions), `new` = 660ed05
(listener-scoped applications, `**.` suffix wildcard domains, fixed-status shares in
weighted backends, route precedence tie-break). `scoped` = the `new` binary started through
`bench/scoped-wrapper.sh`, which gives every application `listeners: [http, https]`: the
same routing, but through the per-listener host routers and the listener-name lookup per
request. All are plain release builds (`cargo build --release --locked -p scalwsd
--features http3`, thin LTO, no PGO or BOLT); `new` and `scoped` are the same binary.

Configuration: `bench/configs/scalws.yaml` unchanged for `base` and `new` (no `listeners`,
no `**.` domain, no fixed-status share). For `scoped` the wrapper inserted
`listeners: [http, https]` into the four applications (list items at indentation 6 in that
file, as the script expects). `bench/multi.sh`, `MODE=release` (10 s warm-up, 30 s
measurement, 5 runs, variant order rotating), medians. Every measurement answered 2xx only;
no run was excluded.

Gate: `new / base` at least 0.98 and `scoped / new` at least 0.98 per scenario.

| scenario | base req/s | new req/s | scoped req/s | new / base | scoped / new | cpu_us base / new / scoped | gate |
|---|---:|---:|---:|---:|---:|---|---|
| static-small | 68 708 | 67 971 | 67 747 | 0.989 | 0.997 | 58.20 / 58.83 / 59.03 | pass |
| respond | 109 684 | 108 695 | 107 691 | 0.991 | 0.991 | 36.45 / 36.79 / 37.13 | pass |
| proxy | 45 296 | 44 973 | 44 681 | 0.993 | 0.994 | 88.31 / 88.92 / 89.51 | pass |
| cache-hit | 85 246 | 83 373 | 83 559 | 0.978 | 1.002 | 46.91 / 47.97 / 47.86 | borderline |

cache-hit new / base was 0.978, so it was repeated alone (same method, 5 more runs,
`xeon-gateway-ab-cache`): base 85 316, new 84 522, scoped 84 742; new / base 0.991,
scoped / new 1.003; cpu_us 46.87 / 47.31 / 47.19. Across the two cache-hit runs the
new / base ratio is 0.978 and 0.991, and the 2026-10-14 report saw the same kind of
spread (0.984, 0.980, 0.991) for this scenario on an unchanged hot path.

Spread of the five runs (req/s, min to max, CV): static-small base 68 462-69 077 (0.4 %),
new 66 704-68 859 (1.3 %), scoped 67 407-68 331 (0.5 %); respond base 109 077-110 296
(0.5 %), new 106 096-110 709 (1.8 %), scoped 106 464-107 807 (0.5 %); proxy base
44 033-45 653 (1.4 %), new 44 852-45 163 (0.3 %), scoped 44 460-45 375 (0.8 %); cache-hit
base 84 865-85 624 (0.4 %), new 82 510-84 506 (1.2 %), scoped 82 439-84 087 (0.8 %).

p99 latency (ms), base / new / scoped: static-small 1.29 / 1.30 / 1.14; respond
0.73 / 0.75 / 0.73; proxy 2.25 / 2.39 / 2.44; cache-hit 1.05 / 1.04 / 0.96.

Peak resident memory (MiB), base / new / scoped: static-small 44 / 44 / 43; respond
44 / 43 / 43; proxy 49 / 48 / 48; cache-hit 49 / 48 / 48.

## Verdict

The gate holds for every scenario. The listener-name lookup of the scoped path costs
0.0 % to 0.9 % of throughput (respond, the most sensitive scenario, 0.991 and about 0.9 %
more CPU per request), so the index-in-`ConnInfo` alternative is not needed. No profile
was taken since the gate holds on the repeat.

The benchmark configuration has an expired test certificate (`bench.test`), which the
server logs as an error at start; the plain-HTTP scenarios measured here are not affected,
and all three variants share it.

Results, in the bench host's results directory: `results/xeon-gateway-ab` and
`results/xeon-gateway-ab-cache` (`aggregate.csv`, `aggregate.txt`,
`run-N`); binaries `/opt/scalws-gw-base`, `/opt/scalws-gw-new`,
`/opt/scalws-gw-scoped`.