# Rate-limit probe results

**Probe date**: 2026-04-29
**Script**: `scripts/probe_rate_limit.py`
**Method**: Ladder test — N requests at decreasing inter-request sleep,
30s recovery between tiers, watch for status != 200, body shrinkage,
or latency degradation.

## oshwhub.com listing API (`/api/project`)

No auth. 6 tiers × 10 reps = 60 reqs total.

| sleep | status | bad | latency p90 |
|---|---|---:|---:|
| 2.0s | all 200 | 0 | 1187ms |
| 1.0s | all 200 | 0 | 1237ms |
| 0.5s | all 200 | 0 | 567ms |
| 0.25s | all 200 | 0 | 1180ms |
| 0.1s | all 200 | 0 | 2194ms |
| 0.0s | all 200 | 0 | 5362ms ← server soft-limits via latency |

**Verdict**: 0.5s safe water mark. Going faster doesn't fail but server adds
queueing latency (no return on the speed-up).

## oshwhub.com detail HTML (`/<owner>/<path>`)

No auth. 6 tiers × 10 distinct paths from batch-50 candidates.

| sleep | status | bad | latency p90 |
|---|---|---:|---:|
| 2.0s | all 200 | 0 | 4767ms |
| 1.0s | all 200 | 0 | 6350ms |
| 0.5s | all 200 | 0 | **15364ms** ← queue building |
| 0.25s | all 200 | 0 | 3755ms |
| 0.1s | all 200 | 0 | 8179ms |
| 0.0s | all 200 | 0 | 3856ms |

**Verdict**: 1.0s safe water mark. Detail HTML is 0.5 MB SSR, server
slowdown earlier than listing API. Going to 0.5s already triggers server
queue (one outlier 15s response), risk of timeout cascades on real bulk runs.

## pro.lceda.cn API (`/api/v4/projects/<P>`)

**Auth required** (logged-in cookie). Conservative ladder, reps capped at 8
to limit fingerprint exposure. 5 tiers × 8 reqs.

| sleep | status | bad | latency p90 |
|---|---|---:|---:|
| 5.0s | all 200 | 0 | 7299ms |
| 2.0s | all 200 | 0 | 5518ms |
| 1.0s | all 200 | 0 | 1409ms |
| 0.5s | all 200 | 0 | 2995ms |
| 0.25s | all 200 | 0 | 1552ms |

Then **sustained burst test** at the chosen water mark:
**25 distinct Pro UUIDs at 0.5s sleep, no recovery**.

- 25/25 success (all status 200, all `success: true`)
- median latency 410ms, p90 932ms, max 1853ms (first call only — TLS handshake)
- effective QPS 1.0
- wall time 24.9s (vs ~140s at the old 5s/req — 5.6× speedup)

**Verdict**: 0.5s safe water mark. Empirically Pro API tolerates QPS=2
cleanly, even sustained. Originally set high (5s) out of caution because
Pro requires a logged-in account — that caution was unjustified.

## lceda.cn Std source endpoints — NOT YET PROBED

Currently `SLEEP_SOURCE = 5.0`. Should be probed before lowering. Std
crawler isn't on the critical path for batch-50 (~12 min vs Pro's
~10 min savings), so this can wait.

## modules.lceda.cn CDN — already at 0.2s

CDN host serving AES-encrypted EPRO2 history blobs. Pre-existing
`SLEEP_PRO_CDN = 0.2`, validated against editor HAR which fires blobs
back-to-back without throttling. No further probing needed.

## Settings applied

```python
SLEEP_BETWEEN = 1.0   # was 2.0  (oshwhub detail/listing)
SLEEP_SOURCE  = 5.0   # unchanged (Std source — not yet probed)
SLEEP_PRO     = 0.5   # was 5.0  (Pro API host, 10× speedup)
SLEEP_PRO_CDN = 0.2   # unchanged (CDN, already optimized)
```

## Net impact on batch-50 plan

- Pro 25 项 × ~5 API calls each: 5×5 = 25s/proj × 25 = ~10min  →  0.5×5 = 2.5s/proj × 25 = ~1min
- Detail page scan 50 项: 50 × 2s = 100s  →  50 × 1s = 50s
- Combined batch-50 walltime estimate: **~1.5h → ~30 min**