Necko Team – Weekly Status Meeting Notes

Date: 2026-03-03
Edition: March
Facilitator: Greg
Next on Triage: Valentin Gosu
Quality Report Coordinators (March): Valentin Gosu / Sunil Mayya

Round Table

Andrew Transitioning to Collaboration Role

• Andrew is rolling off as a full-time Necko team member after ~4 years 🎉

• Moving to a collaboration model between Networking and Performance.

• Will join meetings for agreed joint projects (e.g., Speculation Rules / Prefetch).

• Will no longer attend recurring Necko meetings by default.

• Remains reachable in #necko and #perf-help.

• Team thanked Andrew for his contributions and ongoing partnership.

Gecko Code Review AI Feedback

• Positive experience using AI tooling for code review.

• Identified improvements such as:

  • Cycle collection gaps

  • Spec-step documentation

  • Raw pointer safety notes

• WebTransport exportKeyingMaterial() implementation approved:

  • Spec compliant

  • Secure

  • Thread-safe

  • Well-tested

  • Clean cross-layer integration

• Reinforced value of AI-assisted review for complex networking code.

RCWN (Race Cache With Network) Disablement

• Feature considered technical debt (two code paths).

• Previous experiment showed negligible impact.

• HDD usage now <7% on Windows.

• Decision:

  • Disable RCWN.

  • File tracking bug and prioritize in queue.

  • Focus engineering effort on cache improvements instead.

• Action: File meta bug to disable and eventually remove RCWN code.

Cross-Team Coordination (DevTools)

• Proposal from DevTools to increase cross-team connectivity.

• Decision:

  • Not add to weekly status.

  • Explore quarterly/bi-yearly sync for roadmap alignment.

  • Use Slack for ad-hoc coordination.

• Water cooler remains informal; no structural changes.

Team Check-ins (Highlights)

• Lars

  • PR_POLL implementation progressing.

  • Performance testing positive on Linux/macOS.

  • Windows historical fix landed.

• Kershaw

  • Landed first Happy Eyeballs version.

  • Investigating CrowdStrike / HTTP3 fallback logic.

  • Continuing Happy Eyeballs work.

• Valentin

  • Fixed Necko meeting notes GitHub automation.

  • Landed Sunil’s LNA patches.

  • Working on LNA:

    • Block local network requests from insecure contexts.

    • Avoid prompts when certificate mismatches.

  • Fixed intermittent cookie deletion issue (Windows pref-related).

• Max

  • Fixed long-standing neqo issue.

  • Security fix in QPAC (with Claude assistance).

  • Investigating 10% zero-RTT rejection rate.

  • Continuing Happy Eyeballs Rust reviews.

• Oskar

  • Continuing Hystart++ integration.

  • Addressing review comments before landing.

Important Business

Priority Queue

(Security-sensitive bugs excluded)

Queue status: 23 total (12 assigned, 11 ready).

Closed Fixed (Last Week – Non-Security)

• 1869403 – Slow system proxy page load

Active Projects

FEISTY

• Downloads GCP migration complete and in review.

• Downloads now unblocked.

DoH Enablement – Fenix

Early Nightly experiment data (March 2):

Pageload Event (TRR vs Native):

• p50: +18ms (+257%) slower (early data)

• p75: +16ms (+38%)

• p95: +33ms (+18%)

All DNS Requests:

• p50: +11.7ms (+41%)

• p95: +39ms (+19%)

Cold Applink DNS:

• p75: +74ms (+617%)

• p95: +346ms (+449%)

Time to Request Start:

• p50: +191ms (+43%)

• p75: +273ms (+19%)

Notes:

• Early data; query recently updated.

• Reduced HTTP/3 negotiation rate under TRR.

• Greg: Happy Eyeballs expected to improve H3 negotiation.

Local Network Access (LNA)

• 147: 100% ETP Strict via Nimbus.

• 148: Default enabled for ETP Strict.

• Android Nightly enablement pending review.

• Sunil patches uplifted by Valentin.

• New patch: block LNA requests from insecure contexts.

• Fix in progress to suppress prompts when cert mismatch detected.

Happy Eyeballs

• IPv4/IPv6 preference patch in review.

• Rust/C++ integration ongoing.

• ABI review required before first landing.

• FFI review requested.

QUIC / Hystart++

• Slow start rearchitecture under review.

• Integration work continuing.

Performance Highlights

• Fenix Applink ~12% faster YTD.

• Tracker tailing experiment:

  • Disabling tailing regressed FCP/LCP ~10% @ P50.

  • Follow-up experiments launched (Nightly + Beta).

• 10% zero-RTT rejection rate under investigation.

  • Possible cookie ticket or server behavior.

  • Randell to lead investigation.

Maintenance Effectiveness:

• Last week: 66.67% ⚠️

• Last month: 91.92%

• 3-month trend: 98.7%

WebCompat

Needs attention:

• [2012345

  ](https://bugzilla.mozilla.org/show_bug.cgi?id=2012345)

• 2017305 (possible regressor)

• [2016092

  ](https://bugzilla.mozilla.org/show_bug.cgi?id=2016092)

Reminder:

• Hide PII logs.

• File new component bugs rather than reassigning WebCompat bugs directly.

Decisions & Alignment

• Disable RCWN and remove code.

• Maintain informal DevTools coordination model.

• Continue DoH Nightly experiment; analyze cold applink data.

• Investigate zero-RTT rejection anomaly.

• Keep PQ hygiene; tag good-first-bugs during triage.

Action Items

• Valentin

  • File RCWN disablement bug.

  • Coordinate QR during Sunil PTO.

  • Prepare monthly meeting slides.

  • Continue LNA fixes and uplifts.

• Greg

  • Seed meeting templates before PTO.

  • Coordinate Feisty downloads fallback.

  • Explore structured DevTools sync.

• Max

  • Continue Happy Eyeballs Rust reviews.

  • Investigate zero-RTT rejection rate.

• Kershaw

  • Facilitate Mar 12 meeting.

  • Continue Happy Eyeballs work.

• Team

  • Investigate new WebCompat items.

  • Reduce NI counts (<3).

  • Complete retro actions.