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Necko Team – Weekly Status Meeting Notes

Date: 2026-06-23
Edition: June
Facilitator: Greg
Next on Triage: Sunil Mayya
Quality Report Coordinators (June): Valentin Gosu / Sunil Mayya


Round Table

Bug Bash Day Planning

  • Bug Bash / Hack Day scheduled for Friday, June 26.
  • Team members were asked to propose focus areas and sign up.
  • Suggested focus areas: - Security bug backlog reduction - Intermittent test cleanup - Disabled test areas - WebCompat investigations
  • Greg encouraged everyone to identify work items before the end of the week.

SecPrivNecko Deep Dive (July 14)

  • Necko is scheduled for a deep-dive presentation.
  • Candidate topics discussed: - Compression Dictionaries - Happy Eyeballs - Cache improvements - Congestion control work
  • Oskar will be unavailable due to thesis work.
  • Team leaned toward postponing the Necko deep dive until August and asking another team to present in July.

Engineering Summit

  • Registration deadline: July 13.
  • Greg reminded all team members to register, even if attendance plans are uncertain.

Team Check-ins

Oskar

  • Continued congestion-control experimentation.
  • Shared updated slow-start metrics: - Significant improvement after Lars’ pacing patch. - SEARCH exit rates increased substantially. - More connections now survive long enough for algorithms to take effect.
  • Keeping the current beta experiment running for the full cycle to collect additional data.
  • Also balancing thesis work and upcoming deadline.

Max

  • Continued Happy Eyeballs development.
  • Proposed: - Reduced connection-attempt delay (50ms). - Exponential growth strategy. - Improved negative-DNS-cache handling.
  • Plans to discuss preferred-address-family behavior with networking experts during IETF 126.

Lars

  • Fixed libxul regression caused by NSS-RS integration by switching to dynamic linking.
  • Continued Zero-RTT project planning.
  • Preparing for IETF 126 participation.
  • Working through review feedback on project planning documentation.

Sunil

  • Progress on Speculation Rules implementation.
  • Infrastructure now functional.
  • Targeting first Nightly rollout in mid-July.
  • Preparing: - Remaining review patches - Intent-to-ship for No-Vary-Search - Release-pref enablement for Firefox 153.

Valentin

  • Focused heavily on security backlog.
  • Investigated: - URL deserialization attack surface - URL crash reports - WebExtension-related security work
  • Reported multiple performance improvements from recent patches.
  • Working to clear urgent tasks before upcoming PTO.

Kershaw

  • Fixed multiple Happy Eyeballs crash issues.
  • Refactoring code to improve testability through gtests.
  • Working on connection-race related failures.
  • Continuing ECH and DoH investigations.

Randell

  • Continuing WebTransport and neqo integration work.
  • Investigated Windows Defender interaction with cache metadata.
  • Achieved: - ~9% improvement on regular Windows systems. - Up to ~39% improvement on reference hardware.
  • Also working on GeForce Now compatibility issues and potential L4S collaboration discussions.

Important Business

Priority Queue

Bug IDSeveritySummaryPriorityOwnerStatus
2000423S3FormData parser preamble complianceP2
1974877S3Cookies/samesite WPT failuresP2
1965087S3Cookie creationDate/lastAccessed restoreP2valentin.gosu
1963079N/AExclude spurious document loads telemetryP2
2013783S3Website keeps reloading itselfP2valentin.gosu
2015482N/ABigQuery alerting investigationP2
2019322S3Remove auth type supportP2
2035411S3SSLKEYLOGFILE warningP2valentin.gosuReviews pending
2037956S3dns.trr_success probe missing dataP2
2040187S3ECH never used with configured DoH serverP2kershawInvestigating
2044792S3HTTP/3 DoH timeout connection persistenceP2
1896460S3Improve Blink-compatible sniffingP3valentin.gosuAddressing tests

Active Projects

FEISTY (Firefox Essential Internal Services Toughening)

  • Riding Firefox 153.
  • Alerting probes still needed.
  • Monitoring dashboard remains active.
  • Country-specific improvements still underway.

DoH Enablement (Fenix / Focus)

  • Waiting for additional Happy Eyeballs fixes.
  • New experiment expected to start next week.

Compression Dictionary Transport

  • Firefox 153 rollout ongoing.
  • Discussion around possible SecPrivNecko presentation topic.
  • No major issues reported this week.

WebTransport (Interop 2026)

  • Continued neqo and Gecko integration work.
  • Firefox 154 remains the target release.

Local Network Access

  • Desktop rollout increased to 25%.
  • Android rollout continues in Firefox 153.
  • No significant breakage reported.

QUIC / SEARCH / HyStart++

  • Beta experiment continues.
  • Significant improvement observed after pacing changes.
  • Additional data collection planned before conclusions.

Happy Eyeballs

  • Continued algorithm tuning.
  • Focus on: - Delay reduction - Preferred-family behavior - DNS caching improvements
  • Several crash fixes landed or in progress.

Speculation Rules API

  • First Nightly milestone targeted for mid-July.
  • Review patches being prepared.

Performance & Quality

Notable updates:

Cache Improvements

  • Cache metadata restructuring produced: - ~9% improvement on standard Windows systems. - Up to ~39% improvement on reference hardware.
  • Improvement achieved by reducing Windows Defender interaction overhead.

Congestion Control

  • Positive results from pacing improvements.
  • SEARCH metrics show substantially improved engagement and activation rates.
  • Experiment will continue for the remainder of the cycle.

Happy Eyeballs

  • Ongoing tuning focused on DNS efficiency and connection startup latency.

Security Bug Metrics

sec-high / sec-critical

  • 4 open
  • 0 closed last week
  • 0 added last week

sec-moderate

  • 28 open
  • Net increase of 4 over prior week

Team reminder:

  • Everyone is encouraged to pick up at least one security bug per week to reduce backlog pressure.

WebCompat

New issues requiring investigation:

  • 2047429
  • 2047524
  • 2047099
  • 2048215
  • 2048487
  • 2045020

Continuing investigations:

  • 2042802
  • 2040124
  • 1975238

Guidance remains:

  • Create component bugs rather than moving WebCompat bugs directly.
  • Keep outstanding NIs under three.

Decisions & Alignment

  • Proceed with Bug Bash planning and focus-area registration.
  • Continue Happy Eyeballs tuning and DNS optimization work.
  • Continue congestion-control experimentation through full cycle.
  • Push No-Vary-Search toward release enablement.
  • Postpone Necko SecPriv deep dive to August if needed.
  • Maintain focus on reducing security backlog.

Action Items

Greg

  • Coordinate alternate team for July 14 SecPrivNecko deep dive.
  • Sync with Lars on Zero-RTT planning review.
  • Continue Bug Bash coordination.

Sunil

  • Post remaining Speculation Rules patches for review.
  • Send intent-to-ship for No-Vary-Search.
  • Enable release pref for Firefox 153.

Max

  • Discuss preferred-family behavior with IETF experts.
  • Continue Happy Eyeballs DNS optimizations.

Kershaw

  • Reduce Happy Eyeballs connection delay.
  • Continue Happy Eyeballs stability work.

Lars

  • Address Zero-RTT planning feedback.
  • Continue JIRA review process preparation.

Valentin

  • Continue security bug burn-down.
  • Clear urgent work before PTO.

Oskar

  • Keep congestion-control experiment running.
  • Continue data analysis and dashboard review.

Team

  • Register Engineering Summit attendance by July 13.
  • Sign up for Bug Bash focus areas.
  • Continue helping with security and WebCompat backlogs.