Necko Team – Weekly Status Meeting Notes

Date: 2026-02-17
Edition: February
Facilitator: Greg
Next on Triage: Ed Guloien
Quality Report Coordinators (Feb): Randell Jesup, Ed Guloien

Round Table

Bug Bash Day

• Bug Bash Day rescheduled to this Friday after discussion.

• March 5th option rejected due to availability.

• Proposed focus: Failing assertion bugs (many with Pernosco sessions), currently blocking fuzzing.

• Greg to coordinate and confirm focus areas.

H3 Upload Performance

• Oskar presented updated perfherder graphs comparing Chrome and Firefox.

• Team agreed:

  • The old “3x slower” bug no longer reflects current reality.

  • Close the old bug.

  • File a new follow-up bug tracking the ~300 Mbps scenario (~20% slower than Chrome).

• Kershaw to:

  • Close old bug with summary and benchmarking data.

  • File new tracking bug and link appropriately.

• Ask reporters to re-test.

Spurious Congestion Event Recovery (HTTP/3)

• Data shows significant improvements in spurious congestion event recovery.

• ~11% of users potentially benefit.

• Decision: include this improvement in release notes (pending wording confirmation).

• Oskar to:

  • Propose release note wording in Slack.

  • Announce performance win internally in #perftest.

• Team agreed it is a meaningful performance win.

AI / Performance Analysis Tools

• Claude noted as highly effective for performance profile analysis.

• Denis’ profiler CLI tool shared as a useful companion tool.

• Continued interest in AI-assisted analysis for networking performance and triage.

SecPrivNecko Updates / External Talks

• Dennis and Christoph presenting at UCSD on HTTPS adoption, DoH, ECH, and CRLite.

• Greg requested high-level statistics:

  • ECH: ~0.5% of TLS connections (limited by server support)

  • DoH: ~11% of Firefox network connections

  • Cloudflare remains primary ECH partner

• Graphs from Max’s FOSDEM talk will be shared.

Team Check-ins

Performance Highlights

• Andrew’s Fenix AppLink improvement landed.

  • ~7% improvement bringing Firefox close to Chrome.

• Additional Fenix DoH performance improvements validated via profiles.

• New metrics added to TRR perf tests for:

  • DNS lookup

  • Connection

  • Completion timings

• Perfherder metrics visible and being tracked.

Hystart++ / QUIC

• Hystart++ implementation complete and validated.

• Fixing base architecture issue before opening for review.

LNA Rollout

• LNA rolled out to 100% of ETP Strict users in 147 via Nimbus.

• Plan:

  • Enable by default in 148 for ETP Strict.

  • Continue Android coordination.

• Permission delegation, policy updates, and timeout changes progressing.

Happy Eyeballs

• Continued work; no major blockers reported.

Important Business

Priority Queue

(Security-sensitive bugs excluded)

Bug ID

Severity

Summary

Priority

Owner

Status

1869403

S3

Slow page load with “use system proxy” enabled

P1

kershaw

WIP

2014416

S3

H3 connection to google-analytics.com hanging (early data?)

P1

kershaw

Landing

2000423

S3

FormData parser non-compliant (preamble)

P2

—

—

1974877

S3

WPT failures in /cookies/samesite

P2

—

—

1965087

S3

Cookie creationDate / lastAccessed initialization

P2

edgul

—

1962316

S3

Android VPN + network change incomplete requests

P2

—

—

1732512

S3

Fetch blocked by form submit (NS_BINDING_ABORTED)

P2

smayya

—

1944288

S3

Firefox Android responds to WebSockets in background

P2

acreskey

Starting shortly

1962817

S3

kameleoon.js deprioritization slows render

P2

acreskey

Experiment live

1963079

N/A

Exclude spurious document loads from telemetry

P2

—

—

2014160

S3

Cache2 I/O thread 100% CPU (O(n) search)

P2

jesup

—

1896460

S3

Improve Blink sniffing compat for text/plain

P3

kershaw

WIP

Discussion Notes

• Queue at 26 items (16 assigned).

• Several P1 items recently landed.

• Team reminded to keep NI count under 3 per person.

Active Projects

FEISTY

• AMO and Remote Settings complete.

• Downloads GCP migration nearing final blocker resolution.

DoH Enablement

• Fenix DoH perf improvements landed 🎉.

• Nightly experiment planned to track real-world Fenix performance.

• Continued investigation into socket-thread bottlenecks.

Compression Dictionaries

• Telemetry patches landing.

• Feature enabled in Nightly.

• Monitoring before moving to Beta.

QUIC / Hystart++

• Hystart++ validated; architectural fix in progress.

• Performance graphs shared internally.

LNA

• 100% rollout for ETP Strict in 147.

• Default enablement for 148 in progress.

• Android support patches nearing readiness.

Performance & Metrics

• HTTP/1.1 still used for ~25% more top-level document loads vs prior baselines (under investigation).

• AppLink performance improvement significant.

• Spurious congestion recovery measurable and user-impacting.

• Maintenance Effectiveness (with Sec bugs): 87.5% last week; trending stable long-term.

WebCompat

• New issues under investigation.

• Some require additional logs.

• Reminder: hide attachments containing potential PII.

Decisions & Alignment

• Close outdated H3 upload bug; create follow-up tracking bug.

• Include spurious congestion improvements in release notes (pending wording).

• Proceed with Bug Bash this Friday focusing on assertion bugs.

• Continue LNA rollout and Android coordination.

• Keep performance telemetry improvements prioritized.

Action Items

• Greg

  • Coordinate Bug Bash focus.

  • Share FOSDEM graphs for UCSD talk.

  • Update JIRA tickets for Android LNA rollout.

• Kershaw

  • Close old H3 upload bug and file new tracking bug.

  • Land mitigation patch for H3 zero-RTT stuck issue.

• Oskar

  • Draft release note wording.

  • Announce perf win internally.

• Sunil

  • Land remaining LNA patches.

  • Update blog post draft or propose alternative framing.

• Randell

  • Land telemetry patches for compression dictionaries.

  • Continue WebTransport and WebCompat follow-ups.

• All

  • Review Andrew’s performance updates.

  • Respond to NI requests.

  • Help investigate new WebCompat issues.