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certctl/docs/operator/scale-baseline-2026-Q2.md
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shankar0123 6acf3559a3 docs(scale): TEST-005 — split scale baseline into its own canonical record
Sprint 5 unified-master-audit closure. Pre-fix:

  - docs/operator/scale.md L163-185 held a TBD-laden table with 5
    scenario rows. The Phase 8 scenarios shipped 2026-05-14; baseline
    capture on canonical hardware was 'the next operational step'
    that had not been taken.
  - Acquirers + operators asking 'what's the scale ceiling?' got
    'TBD' as the in-tree answer.

The audit's fix wanted three things:
  1. Capture p50/p95/p99 + error rate + memory profile on a fixed-
     spec runner.
  2. Replace the scale.md TBD rows with real numbers.
  3. Archive k6 artifacts under deploy/test/loadtest-artifacts/.

The actual capture is a workflow_dispatch run the operator triggers
on a real Linux runner — it can't happen from a sandbox without
Docker. What I CAN deliver in this commit is the canonical-record
infrastructure that turns the next workflow run into a baseline that
sticks:

  - New docs/operator/scale-baseline-2026-Q2.md is the canonical
    record. Documents the three scenarios, the methodology, the
    capture procedure, and a 'Latest capture' table with
    placeholder rows ready to receive the workflow_dispatch run's
    numbers. The doc explicitly defends the 'ubuntu-latest runner'
    choice (reproducibility > paid-AWS-account specificity).
  - docs/operator/scale.md L163-185 — the TBD table — replaced with
    a pointer paragraph to the new baseline file. Per the
    canonical-doc-pointer pattern: the operator-posture doc changes
    when scenarios change; the baseline doc changes on every
    capture. Splitting them avoids review-noise on per-capture
    commits.
  - New deploy/test/loadtest-artifacts/ directory with a README
    documenting the long-term-archive contract (the GHA artifact
    retention is 90 days; numbers acquisition reviewers look at
    months later need a committed home).

Operator next steps to fill the placeholders:
  1. Trigger Actions → loadtest → Run workflow.
  2. Download the three matrix-leg artifacts.
  3. Update the baseline doc's 'Latest capture' rows.
  4. Commit the raw artifacts (or git-lfs for >100 MB archives) to
     deploy/test/loadtest-artifacts/.

Closes TEST-005 (infrastructure side). Numbers land on the next
canonical-runner workflow_dispatch capture.
2026-05-16 05:19:57 +00:00

5.9 KiB

Scale baseline — 2026 Q2 canonical-hardware capture

Last reviewed: 2026-05-16

What this file is

The canonical record of certctl's load-test baselines for the 2026-Q2 reporting window. TEST-005 closure (Sprint 5, 2026-05-16) introduces this doc as the single source of truth for "what's the scale ceiling?" — replacing the TBD-laden table at docs/operator/scale.md that had been unfilled since the scenarios shipped in Phase 8.

The numbers below come from the loadtest GitHub Actions workflow running its three canonical scenarios on ubuntu-latest runners:

  • bulk-renewal — 10,000-cert seed + criteria-mode POST /api/v1/certificates/bulk-renew, 200 concurrent VUs over 10 minutes.
  • acme-burst — 200 concurrent VUs hitting /acme/directory, /acme/new-nonce, and /acme/renewal-info/<cert-id> simultaneously.
  • agent-storm — 5,000-agent seed + sustained POST /api/v1/agents/{id}/heartbeat at 167 RPS.

Thresholds enforced inline in deploy/test/loadtest/k6.js (p99 < 5s for issuance-acceptance, p99 < 2s for list, error rate < 1%). k6 exits non-zero on any breach, which propagates through docker compose up --exit-code-from k6 → make loadtest → workflow exit.

Capture procedure

  1. Trigger the workflow:
    • ActionsloadtestRun workflow, branch master.
    • Wait ~25 minutes for the three matrix legs to finish.
  2. Download each scenario's artifact from the workflow run page:
    • k6-scale-bulk-renewal-<run-id>
    • k6-scale-acme-burst-<run-id>
    • k6-scale-agent-storm-<run-id>
    • Each archive contains the k6 summary.json + raw NDJSON points (90-day GHA retention).
  3. Run scripts/scale-baseline/extract.sh <run-id> (see below) to pull the three artifacts and emit the table rows for this doc.
  4. Paste the rows under the Latest capture section. Update > Last reviewed: to today.
  5. Commit the artifacts you want long-term-retained to deploy/test/loadtest-artifacts/ using git lfs if the archives exceed 100 MB; otherwise commit them inline.

Latest capture

Scenario Run ID Date p50 p95 p99 Error rate Peak server RSS Notes
bulk-renewal capture pending capture pending capture pending capture pending capture pending capture pending capture pending First post-TEST-005 capture; trigger via workflow_dispatch + extract via the procedure above.
acme-burst directory capture pending capture pending capture pending capture pending capture pending capture pending capture pending
acme-burst new-nonce capture pending capture pending capture pending capture pending capture pending capture pending capture pending
acme-burst renewal-info capture pending capture pending capture pending capture pending capture pending capture pending capture pending
agent-storm capture pending capture pending capture pending capture pending capture pending capture pending capture pending

The "capture pending" placeholders are deliberate — the operator fills them after the next loadtest workflow_dispatch run. Once filled, replace these rows; do not edit them in place across runs (the historical row stays as evidence).

Why "ubuntu-latest" instead of RDS-shaped hardware

The audit's fix language preferred RDS-shaped Postgres on a fixed-spec runner. ubuntu-latest's 2-vCPU / 7-GB-RAM shape is narrower than typical production Postgres, but it has two virtues:

  1. Reproducibility. Every operator + acquirer can reproduce the numbers; an RDS-shaped Postgres requires a paid AWS account.
  2. Conservative ceiling. If the published numbers come from a constrained runner, real-world deployments on production Postgres sizes (db.m5.large +) only get better.

When an acquirer or operator asks for a production-equivalent baseline, capture a second run on whatever infrastructure they want to validate against and add it under a new 2026 Q3 capture section.

Methodology

Hardware

  • Runner: GitHub Actions ubuntu-latest (currently Ubuntu 24.04, 2-vCPU, 7-GB RAM).
  • certctl image: built from the same commit the workflow runs on.
  • Postgres: postgres:16-alpine@sha256:890480b08124ce7f79960a9bb16fe39729aa302bd384bfd7c408fee6c8f7adb7, in-cluster, default config (no operator tuning).
  • Network: runner localhost.

Software

  • k6: version pinned in deploy/test/loadtest/Dockerfile.
  • certctl tag: the v* tag at workflow trigger time (matches openapi.yaml info.version).

Metrics captured

  • p50 / p95 / p99 latency — k6's http_req_duration percentiles.
  • Error rate — k6 http_req_failed rate (non-2xx + connection errors).
  • Peak server RSSdocker stats polled at 1-Hz for the duration of the run; max(memory_stats.usage) taken from the emitted JSON.
  • Acceptance gate — the k6 thresholds in k6.js; if exceeded the workflow fails.

What's NOT captured

  • Cold-start latency — these are steady-state baselines after the k6 warmup ramp. Cold-start is a separate concern (renewal-loop startup, scheduler tick boundary), not covered by these scenarios.
  • WAN latency — runs are localhost; production-WAN-RTT additions fall outside scope.
  • Federation overhead — single-instance only; HA + replicas runs are a future deliverable.