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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 IDSeveritySummaryPriorityOwnerStatus
1869403S3Slow page load with “use system proxy” enabledP1kershawWIP
2014416S3H3 connection to google-analytics.com hanging (early data?)P1kershawLanding
2000423S3FormData parser non-compliant (preamble)P2——
1974877S3WPT failures in /cookies/samesiteP2——
1965087S3Cookie creationDate / lastAccessed initializationP2edgul—
1962316S3Android VPN + network change incomplete requestsP2——
1732512S3Fetch blocked by form submit (NS_BINDING_ABORTED)P2smayya—
1944288S3Firefox Android responds to WebSockets in backgroundP2acreskeyStarting shortly
1962817S3kameleoon.js deprioritization slows renderP2acreskeyExperiment live
1963079N/AExclude spurious document loads from telemetryP2——
2014160S3Cache2 I/O thread 100% CPU (O(n) search)P2jesup—
2015000S4LoadInfo copy constructor missing 4 fieldsP2——
1896460S3Improve Blink sniffing compat for text/plainP3kershawWIP

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.