The routing surface the short-comp benchmarks validated is (motion x DOM
size x frames). After the baseline release, fleet telemetry carries DOM
size (composition_element_count) and frames on every render — but the
motion proxy, observability_init_tween_count, has 0% coverage on the
exact renders the band routes: parallel workers' console buffers (and so
the [FrameCapture:INIT] line the summary parses) only propagate to the
orchestrator on FAILURE. Single-worker screenshot renders report it;
the multi-worker clamp bucket never does. Verified against 7d of fleet
data: 35k screenshot renders carry tween counts, 0 of 9,600 band renders.
Fix rides the one channel parallel workers already return on success —
the per-worker CapturePerfSummary. Sessions record initTelemetry on
every init path; the perf summary now carries it; the orchestrator
max-merges across workers (same multi-session semantics the console
parser uses) and feeds it to the observability summary as a structured
fallback, console lines still refining when present.
With this, every band render carries full coordinates — (elements,
tweens, frames, path, speed) — which buys two reads: regressing wild DE
speed against element count on the existing 900+ inversions validates
the bench's 0.50ms/element slope BEFORE the routing flip, and any
post-flip misroute can be reproduced locally by feeding its telemetry
row straight into gen-crossover-comp's knobs (--movers ~ tween count,
--static ~ element count) and re-benching.
(Also drops a now-stale fallow suppression in render.ts — the test-only
reset export it guarded gained real test importers, so the issue it
suppressed no longer exists and the gate flags the leftover.)
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Three review findings on the win32 drawElement PR:
1. gpu_renderer shipped the raw UNMASKED_RENDERER_WEBGL string — unbounded,
driver-authored, GPU-model-specific, and |-joined across parallel
sessions, i.e. high cardinality by construction, against this file's own
convention of sanitizing engine-sourced strings (deGateReason is a
bucket; error messages go through redactTelemetryString). Now bucketed at
the source by classifyGpuRenderer to <backend>/<vendor>
(metal/apple, d3d11/nvidia, swiftshader/other, ...), which is the whole
analytic signal the win32 rollout needs and nothing else. The raw string
never leaves the engine.
2. gpu_renderer reached render_complete only, so a crashed render — the
cohort the field exists to attribute — carried no backend. It now rides
RenderCaptureObservability (deGpuRenderer, sourced from the live probe
session like the de_* counters), so both render_complete and
render_error carry it and a hard failure still reports its GPU backend.
On render_complete the perfSummary value still wins by spread order.
3. Restore the fallow-ignore-next-line suppression above
__resetDeParallelRouterTrialStateForTests: CLI test files are not fallow
entry points, so removing it fails the CI dead-code audit (local
pre-commit passed only because of its changed-file scope).
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Widen the default-on drawElement clamp from darwin-only to darwin|win32
(still requiring a non-software-GPU browser). The darwin restriction was a
validation envelope, not an architectural limit — the CanvasDrawElement
Chrome flag ships on every platform, and every safety layer that made the
macOS default-on release (v0.7.38) survivable is platform-neutral:
compile-time gates, the SwiftShader init gate, per-render worker-encode
self-verification with screenshot fallback, and the blank guard. Worst case
on an unvalidated D3D11 backend is the same as on Metal: verify catches a
bad frame and the render re-runs on the screenshot baseline.
Why now: 30-day telemetry shows ~206k non-CI hardware-GPU Windows renders
(~78% of the win32 fleet, 18k installs) held on the slow screenshot path by
the clamp — the second-largest perf population after macOS, carrying ~1,550
capture-hours/month in the DE-eligible >=700-frame band alone at a measured
~2x speedup opportunity.
Instrumentation for the new cohort: drawElement session init now records the
raw WebGL UNMASKED_RENDERER_WEBGL string (detectSwiftShader generalized to
detectGpuBackend — same single evaluate, the string was previously read and
discarded) and threads it session -> CapturePerfSummary -> RenderPerfSummary
-> render_complete as `gpu_renderer`. drawElement damage proved
compositor-backend-specific throughout the macOS rollout, so D3D11-cohort
failures must cluster by ANGLE backend + GPU vendor (NVIDIA/AMD/Intel), not
just `os`.
The two DE clamp branches are extracted into a pure, unit-tested
`resolveDefaultDrawElement` (platform + GPU mode + worker-encode + explicit
opt-in), which also drops resolveConfig's cyclomatic complexity. The win32
streaming-encode compound tests collapse onto one shared helper.
Linux stays excluded: that fleet is headless/Docker SwiftShader, where DE
has no speedup and known rendering defects. Kill switches unchanged:
PRODUCER_EXPERIMENTAL_FAST_CAPTURE=false, --experimental-fast-capture=false.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
* fix(producer): accept partial color metadata in plan v2
* test(engine): make partial color probe hermetic
* fix(producer): validate plan v2 sentinels in fallback mode
Vance Ingalls