feat(diag): comprehensive high-concurrency measurement build

User asked to measure everything so we can pinpoint the lag/ECONNRESET at 70 concurrent uploads. All additive instrumentation, no upload-behavior change.

main process: the eventloop-delay log line now also reports cpu=X%core (process.cpuUsage delta over wall time; >100% means multiple cores), rss, per-hoster live connection distribution (active-by-hoster), cumulative transient (ECONNRESET-class) error count, and pending count — pulled from a new UploadManager.getDiagnostics(). This shows whether the main thread is CPU-bound and which hoster is oversubscribed.

renderer: a PerformanceObserver('longtask') plus a requestAnimationFrame frame-time monitor log 'renderer-perf' every 5s while uploading — fps, jankFrames (>33ms), worstFrame, longtask count and max. This is the direct renderer ground truth (real frame rate under load), which the component-timing harness could not capture. Low fps / high jank => renderer is blocked; ~60fps while it still feels laggy => the cpu/eld numbers in the same log decide CPU-bound vs IO-bound in the main process.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

lib/upload-manager.js

@@ -34,10 +34,11 @@ class UploadManager extends EventEmitter {
     this.stopAfterActive = false;
     this.statsInterval = null;
     this.startTime = 0;
-    this.activeJobs = new Map(); // uploadId -> { jobId, speedKbs, bytesUploaded }
+    this.activeJobs = new Map(); // uploadId -> { jobId, speedKbs, bytesUploaded, hoster }
     this.jobAbortControllers = new Map(); // jobId -> AbortController
     this.cancelledJobIds = new Set();
     this.sessionBytes = 0;
+    this._transientErrorTotal = 0;
     this.lastStartTime = {}; // hoster -> timestamp of last upload start
     this.intervalLocks = {}; // hoster -> Promise chain for serialized interval waits
     this.globalThrottle = null;
@@ -81,6 +82,17 @@ class UploadManager extends EventEmitter {
     return this.activeJobs.size;
   }
 
+  getDiagnostics() {
+    const activeByHoster = {};
+    for (const v of this.activeJobs.values()) {
+      const h = v && v.hoster ? v.hoster : 'unknown';
+      activeByHoster[h] = (activeByHoster[h] || 0) + 1;
+    }
+    let pending = 0;
+    for (const sem of Object.values(this.semaphores)) pending += (sem && sem.pending) || 0;
+    return { activeByHoster, transientErrors: this._transientErrorTotal, pending, active: this.activeJobs.size };
+  }
+
   clearFailedAccount(hoster, accountId) {
     return this._failedAccounts.delete(`${hoster}:${accountId}`);
   }
@@ -625,7 +637,7 @@ class UploadManager extends EventEmitter {
           // Mutate this single object on each progress callback instead of
           // allocating a fresh one — callback fires on every stream chunk
           // (hundreds/sec per active job).
-          const activeEntry = { jobId, speedKbs: 0, bytesUploaded: 0 };
+          const activeEntry = { jobId, speedKbs: 0, bytesUploaded: 0, hoster: task.hoster };
           this.activeJobs.set(uploadId, activeEntry);
 
           let lastEmitTime = 0;
@@ -686,6 +698,7 @@ class UploadManager extends EventEmitter {
           return;
         } catch (err) {
           this.activeJobs.delete(uploadId);
+          if (this._isTransientNetworkError(err)) this._transientErrorTotal++;
 
           const isSpeedRestart = speedAbort && speedAbort.signal.aborted && !signal.aborted;
           if (!signal.aborted && !isSpeedRestart) {
@@ -938,7 +951,7 @@ class UploadManager extends EventEmitter {
             let lastBytes = 0;
             let lastSpeedTime = jobStart;
             let currentSpeedKbs = 0;
-            const activeEntry = { jobId, speedKbs: 0, bytesUploaded: 0 };
+            const activeEntry = { jobId, speedKbs: 0, bytesUploaded: 0, hoster: task.hoster };
             this.activeJobs.set(uploadId, activeEntry);
 
             let lastEmitTime = 0;
@@ -1074,7 +1087,7 @@ class UploadManager extends EventEmitter {
       let lastBytes = 0;
       let lastSpeedTime = jobStart;
       let currentSpeedKbs = 0;
-      const activeEntry = { jobId, speedKbs: 0, bytesUploaded: 0 };
+      const activeEntry = { jobId, speedKbs: 0, bytesUploaded: 0, hoster: task.hoster };
       this.activeJobs.set(uploadId, activeEntry);
       let lastEmitTime = 0;
       const PROGRESS_EMIT_INTERVAL = 250;

main.js

@@ -30,6 +30,8 @@ const { createAgent } = require('./lib/diagnostics-agent');
 const _eventLoopDelay = monitorEventLoopDelay({ resolution: 10 });
 _eventLoopDelay.enable();
 let _eldLastLog = 0;
+let _lastCpu = process.cpuUsage();
+let _lastCpuT = Date.now();
 
 let mainWindow;
 let _lastImportPath = null;
@@ -205,7 +207,25 @@ function _maybeLogEventLoopDelay(activeJobs) {
       const top = Object.entries(hist).sort((a, b) => b[1] - a[1]).slice(0, 6).map(([k, v]) => `${k}:${v}`).join(',');
       resStr = ` resources=${info.length} {${top}}`;
     } catch {}
-    logInfo('perf', `eventloop-delay active=${activeJobs} mean=${mean}ms p99=${p99}ms max=${max}ms stddev=${stddev}ms threadpool=${process.env.UV_THREADPOOL_SIZE}${resStr}`);
+    let cpuStr = '';
+    try {
+      const d = process.cpuUsage(_lastCpu);
+      const wall = now - _lastCpuT;
+      const pct = wall > 0 ? Math.round((d.user + d.system) / 1000 / wall * 100) : 0;
+      const rss = Math.round(process.memoryUsage().rss / 1048576);
+      cpuStr = ` cpu=${pct}%core rss=${rss}MB`;
+      _lastCpu = process.cpuUsage();
+      _lastCpuT = now;
+    } catch {}
+    let upStr = '';
+    try {
+      if (uploadManager && typeof uploadManager.getDiagnostics === 'function') {
+        const d = uploadManager.getDiagnostics();
+        const byHoster = Object.entries(d.activeByHoster || {}).map(([h, c]) => `${h.replace(/\..*$/, '')}:${c}`).join(',');
+        upStr = ` active-by-hoster={${byHoster}} transient-errs=${d.transientErrors || 0} pending=${d.pending || 0}`;
+      }
+    } catch {}
+    logInfo('perf', `eventloop-delay active=${activeJobs} mean=${mean}ms p99=${p99}ms max=${max}ms stddev=${stddev}ms threadpool=${process.env.UV_THREADPOOL_SIZE}${cpuStr}${resStr}${upStr}`);
     _eventLoopDelay.reset();
   } catch {}
 }

renderer/app.js

@@ -18,6 +18,37 @@ let config = { hosters: {}, hosterSettings: {}, globalSettings: {} };
 let hosterSettings = {};
 let uploading = false;
 let healthCheckRunning = false;
+
+let _rLongTasks = 0, _rLongTaskMax = 0, _rFrameLast = 0, _rFrameWorst = 0, _rFrameCount = 0, _rFrameJank = 0, _rPerfLastLog = 0, _rPerfWindowStart = 0;
+try {
+  if (window.PerformanceObserver) {
+    new window.PerformanceObserver((list) => {
+      for (const e of list.getEntries()) { _rLongTasks++; if (e.duration > _rLongTaskMax) _rLongTaskMax = e.duration; }
+    }).observe({ entryTypes: ['longtask'] });
+  }
+} catch {}
+function _rFrameTick(ts) {
+  if (_rFrameLast) { const d = ts - _rFrameLast; _rFrameCount++; if (d > _rFrameWorst) _rFrameWorst = d; if (d > 33) _rFrameJank++; }
+  _rFrameLast = ts;
+  requestAnimationFrame(_rFrameTick);
+}
+requestAnimationFrame(_rFrameTick);
+function _resetRendererPerf() {
+  _rPerfWindowStart = Date.now();
+  _rFrameCount = 0; _rFrameJank = 0; _rFrameWorst = 0; _rLongTasks = 0; _rLongTaskMax = 0;
+}
+function _maybeLogRendererPerf(activeJobs) {
+  const now = Date.now();
+  if (!_rPerfWindowStart) _rPerfWindowStart = now;
+  if (now - _rPerfLastLog < 5000) return;
+  const winSec = (now - _rPerfWindowStart) / 1000;
+  const fps = winSec > 0 ? Math.round(_rFrameCount / winSec) : 0;
+  if (window.api && window.api.debugLog) {
+    window.api.debugLog(`renderer-perf active=${activeJobs} fps=${fps} jankFrames=${_rFrameJank} worstFrame=${Math.round(_rFrameWorst)}ms longtasks=${_rLongTasks} maxTask=${Math.round(_rLongTaskMax)}ms`);
+  }
+  _rPerfLastLog = now;
+  _resetRendererPerf();
+}
 let accountStatuses = {}; // { accountId: { status: 'ok'|'warn'|'error'|'checking'|'unchecked', message: '' } }
 let editingAccountId = null; // null = adding, string = editing account by ID
 let autoHealthCheckEnabled = true;
@@ -2539,6 +2570,12 @@ function _handleStatsImpl(data) {
   updateStatusBar();
   updateStatsPanel();
 
+  if (data.state === 'uploading' && (data.activeJobs || 0) > 0) {
+    _maybeLogRendererPerf(data.activeJobs);
+  } else {
+    _resetRendererPerf();
+  }
+
   // Track run time
   if (data.state === 'uploading' || data.state === 'stopping') {
     if (!statsStartTime) {