OmniRoute/docs/PERF_BUDGETS.md

Performance Budgets — OmniRoute (2026-06-18)

Status: Authoritative. SLO targets that the 71-pillar audit (L13) references for the Perf > 2.00 gate. Methodology: per-endpoint p50/p95/p99 latency budgets, plus a top-level availability SLO. Budgets are derived from the 3-replica Caddy + Redis topology (commit 038439fa7); adjust on infra change. Enforcement: none yet. § 6 sketches a benches/perf-gate.k6.js k6 script that would assert the SLOs below, but it is a design reference, not a committed file — no bench/ or benches/ directory exists in this repo today. This doc is a target-setting reference only until a CI gate is built as follow-up work. Re-evaluation cadence: quarterly, or on any major infra change.

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1. Top-level SLOs

SLO	Target	Window	Page on breach
Availability (2xx or 4xx for /v1/* and /api/settings/*)	99.9%	rolling 30 days	on-call P2
Error budget burn rate (1xx normalized rate)	< 2x for 1h, < 6x for 5m	1h / 5m windows	on-call P1
Aggregate p95 latency (all /v1/*)	≤ 1.5 s	rolling 5 min	on-call P2
Aggregate p99 latency (all /v1/*)	≤ 4.0 s	rolling 5 min	on-call P2

Error budget: 30-day window = 43.2 minutes of unavailability at 99.9%. Burn rate > 2x is P2; > 6x is P1.

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2. Per-endpoint latency budgets

All budgets measured server-side (Next.js Route Handler entry to response start, or last byte for streaming). Stream endpoints are measured to time-of-first-byte (TTFB) since the body is incremental.

2.1 Inference endpoints (the hot path)

Endpoint	Method	p50	p95	p99	Notes
/v1/responses (non-stream)	POST	800 ms	1.8 s	3.5 s	Includes translator + provider roundtrip
/v1/responses (stream)	POST (TTFB)	350 ms	900 ms	1.8 s	TTFB only; total duration unbounded
/v1/relay/chat/completions (non-stream)	POST	1.0 s	2.2 s	4.0 s	Includes per-(token,IP) rate-limit check
/v1/relay/chat/completions (stream)	POST (TTFB)	400 ms	1.0 s	2.0 s
/v1/embeddings	POST	300 ms	700 ms	1.4 s	Pure provider roundtrip; cheap
/v1/rerank	POST	600 ms	1.4 s	2.8 s
/v1/moderations	POST	250 ms	600 ms	1.2 s	Lightweight classification
/v1/audio/speech	POST	1.2 s	3.0 s	6.0 s	Audio synthesis is slow; budget reflects that
/v1/audio/transcriptions	POST	2.0 s	5.0 s	10.0 s	STT is bounded by audio duration + model size
/v1/images/generations	POST	4.0 s	8.0 s	15.0 s	Image gen is async-bound by provider
/v1/videos/generations	POST (TTFB)	600 ms	1.5 s	3.0 s	Async; client polls /v1/videos/{id}
/v1/music/generations	POST	3.0 s	6.0 s	12.0 s

2.2 Files + batches

Endpoint	Method	p50	p95	p99	Notes
/v1/files (GET)	GET	80 ms	200 ms	400 ms	Cached list
/v1/files (POST upload)	POST	500 ms	1.2 s	2.5 s	25 MB cap; multipart parse
/v1/files/{id} (GET)	GET	60 ms	150 ms	300 ms
/v1/files/{id} (DELETE)	DELETE	80 ms	200 ms	400 ms
/v1/files/{id}/content (download)	GET	100 ms	300 ms	600 ms	+ per-MB throughput
/v1/batches (GET)	GET	150 ms	400 ms	800 ms
/v1/batches (POST create)	POST	200 ms	500 ms	1.0 s	Validates input file then enqueues
/v1/batches/{id} (GET)	GET	100 ms	300 ms	600 ms
/v1/batches/{id} (DELETE)	DELETE	100 ms	300 ms	600 ms
/v1/batches/delete-completed (POST)	POST	400 ms	1.0 s	2.0 s	Mass delete; n rows

2.3 Agents

Endpoint	Method	p50	p95	p99	Notes
/v1/agents/health	GET	1.5 s	4.5 s	5.0 s	5s per-provider timeout cap; expect 3-provider total
/v1/agents/credentials	GET	100 ms	250 ms	500 ms	Metadata only; values never returned
/v1/agents/tasks (GET list)	GET	150 ms	400 ms	800 ms
/v1/agents/tasks (POST create)	POST	250 ms	600 ms	1.2 s	Just enqueues; doesn't run agent
/v1/agents/tasks/{id} (GET)	GET	100 ms	300 ms	600 ms
/v1/agents/tasks/{id} (DELETE)	DELETE	150 ms	400 ms	800 ms

2.4 Combos / me / providers

Endpoint	Method	p50	p95	p99
/v1/combos	GET	80 ms	200 ms	400 ms
/v1/me/status	GET	60 ms	150 ms	300 ms
/v1/providers/{provider}/models	GET	100 ms	250 ms	500 ms

2.5 Web / search

Endpoint	Method	p50	p95	p99	Notes
/v1/web/fetch	POST	1.5 s	4.0 s	8.0 s	10s timeout cap; recurse depth 3
/v1/search	POST	800 ms	2.0 s	4.0 s	Provider search latency varies

2.6 VSCode-CLI shim (token-scoped)

These are the legacy passthrough paths. Budgets are tighter because they're called frequently by the VSCode-CLI extension in tight loops.

Endpoint	Method	p50	p95	p99
/v1/vscode/{token}/v1/chat/completions	POST	700 ms	1.6 s	3.0 s
/v1/vscode/{token}/v1/models	GET	60 ms	150 ms	300 ms
/v1/vscode/{token}/combos	GET	80 ms	200 ms	400 ms
/v1/vscode/{token}/chat/completions (legacy)	POST	700 ms	1.6 s	3.0 s
/v1/vscode/{token}/models (legacy)	GET	60 ms	150 ms	300 ms
/v1/vscode/{token}/responses	POST	800 ms	1.8 s	3.5 s

2.7 Management / settings

Management endpoints are operator-only and not part of the hot path. Budgets are set conservatively; breaches don't page on-call but do flag in the weekly perf review.

Endpoint group	p50	p95	p99
/api/settings/* (GET)	100 ms	300 ms	600 ms
/api/settings/* (POST/PATCH/DELETE)	200 ms	500 ms	1.0 s
/api/keys/* (CRUD)	150 ms	400 ms	800 ms
/api/quota/* (CRUD)	150 ms	400 ms	800 ms
/api/monitoring/health (heavy)	500 ms	1.5 s	3.0 s

2.8 Public probes

Endpoint	Method	p50	p95	p99
/api/health/ping	GET	5 ms	20 ms	50 ms
/api/monitoring/health	GET	5 ms	20 ms	50 ms
/api/docs	GET	20 ms	80 ms	200 ms (HTML shell, no provider call)

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3. Throughput targets

Tier	Per-replica RPS	Cluster RPS (3 replicas)	Notes
Inference (non-stream)	50 RPS	150 RPS	Bounded by provider quota + translator CPU
Inference (stream)	25 concurrent streams	75 streams	Bounded by Node event-loop + memory
Embeddings	200 RPS	600 RPS	Cheap
Files (upload)	10 RPS	30 RPS	Multipart parse + DB write
Files (download)	100 RPS	300 RPS	Static-content via Next.js
Combos / me / providers	500 RPS	1,500 RPS	Cached
WebSocket	100 concurrent connections	300	Per-IP cap 5

Cluster ceiling (all endpoints combined, sustained): ~1,000 RPS before p95 latency begins to climb. Scale horizontally beyond that by adding replicas; the Caddy LB is stateless.

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4. Resource budgets

Resource	Per-replica cap	Notes
RSS memory	1.5 GB	Spikes during audio/video gen; expect brief 2 GB
Event-loop lag (p99)	50 ms	Alert via clinic doctor regression
Heap retained	800 MB	Old-gen GC tuning in node --max-old-space-size
File descriptors	2,000	ulimit -n 4096 recommended at host
DB connections (sql.js)	1 per replica	sql.js is in-process; no pool needed
Redis connections	20 per replica	Pooled; idle reaped at 5 min

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5. Cold-start budget

Next.js App Router cold-start on a fresh container:

Phase	Budget
Container start → HTTP listening	≤ 800 ms
First request TTFB (warm)	≤ 200 ms
Translator registry bootstrap	≤ 500 ms (one-time, first /v1/responses)

Measurement script: bin/cold-start-bench.sh (already in the repo since v3.8.36; bin/ is the canonical scripts dir).

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6. Regression gate (k6 reference, not yet implemented)

The sketch below shows how a future benches/perf-gate.k6.js script would assert the SLOs above. Nothing in this section is committed or wired into CI today — it is a design reference for follow-up work, not a running gate.

// benches/perf-gate.k6.js — pseudo-code; not yet committed
import http from 'k6/http';
import { check, Trend } from 'k6';

const responsesTTFB = new Trend('v1_responses_ttfb', true);

export const options = {
  scenarios: {
    smoke: {
      executor: 'constant-vus',
      vus: 10,
      duration: '1m',
    },
  },
  thresholds: {
    'http_req_duration{endpoint:v1_responses}': ['p(95)<1800', 'p(99)<3500'],
    'http_req_failed': ['rate<0.01'],
    'v1_responses_ttfb': ['p(95)<900'],
  },
};

export default function () {
  const res = http.post(`${__ENV.BASE_URL}/api/v1/responses`, JSON.stringify({
    model: 'gpt-4o-mini',
    input: 'ping',
  }), { headers: { 'Authorization': `Bearer ${__ENV.API_KEY}` }});
  check(res, { 'status is 200': (r) => r.status === 200 });
  responsesTTFB.add(res.timings.waiting);
}

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7. Review log

Date	Reviewer	Change
2026-06-18	security-circle lead	Initial per-endpoint budgets derived from 3-replica Caddy + Redis topology
2026-07-18	observability-circle	Clarified this doc ships zero enforcement today (no bench//benches/ dir, no CI gate) and fixed the stale "not yet committed" claim about bin/cold-start-bench.sh (present since v3.8.36).
2026-07-18 (planned)	observability-circle	Wire benches/perf-gate.k6.js into CI; gate on p95 + p99 breach
2026-09-18 (planned)	observability-circle	Quarterly review; adjust after real-traffic baseline data