Sentry Advanced Troubleshooting

import * as Sentry from '@sentry/node';

Sentry.init({
  dsn: process.env.SENTRY_DSN,
  debug: true, // Prints all SDK decisions to console

  // Wrap transport to log every outbound envelope
  transport: (options) => {
    const transport = Sentry.makeNodeTransport(options);
    return {
      ...transport,
      send: async (envelope) => {
        const [header, items] = envelope;
        console.log('[Sentry Transport] Outbound envelope:', {
          event_id: header.event_id,
          sent_at: header.sent_at,
          item_count: items?.length,
        });
        const result = await transport.send(envelope);
        console.log('[Sentry Transport] Response:', result);
        return result;
      },
    };
  },
});

async function diagnoseEventDrop(): Promise<void> {
  // Layer 1: Is the client alive?
  const client = Sentry.getClient();
  if (!client) {
    console.error('FAIL: Sentry client is null — SDK never initialized');
    console.error('Check: Is instrument.mjs loaded via --import flag?');
    return;
  }

  // Layer 2: Is the DSN valid and reachable?
  const dsn = client.getDsn();
  if (!dsn) {
    console.error('FAIL: DSN is null — check SENTRY_DSN env var');
    return;
  }
  console.log('DSN:', `${dsn.protocol}://${dsn.host}/${dsn.projectId}`);

  // Layer 3: Is beforeSend silently dropping events?
  const opts = client.getOptions();
  if (opts.beforeSend) {
    console.warn('WARN: beforeSend is configured — it may be returning null');
    console.warn('Test by temporarily removing beforeSend to isolate');
  }

  // Layer 4: Is sampling dropping events?
  console.log('sampleRate:', opts.sampleRate ?? '1.0 (default)');
  console.log('tracesSampleRate:', opts.tracesSampleRate ?? 'not set');
  if (opts.sampleRate === 0) {
    console.error('FAIL: sampleRate is 0 — ALL error events are dropped');
  }

  // Layer 5: Fire a test event and verify delivery
  const eventId = Sentry.captureMessage('Diagnostic probe — safe to ignore', 'debug');
  console.log('Test event ID:', eventId || 'NONE — event was dropped before send');

  // Layer 6: Flush the transport buffer
  const flushed = await Sentry.flush(10000);
  console.log('Flush result:', flushed ? 'SUCCESS' : 'TIMEOUT — likely network issue');
  if (!flushed) {
    console.error('Events are queued but cannot reach Sentry — check network/proxy');
  }
}

# Test your tunnel endpoint returns 200 and forwards to Sentry
curl -v -X POST "https://yourapp.com/api/sentry-tunnel" \
  -H "Content-Type: application/x-sentry-envelope" \
  -d '{"dsn":"https://key@o0.ingest.sentry.io/123"}
{"type":"event"}
{"message":"tunnel test","level":"info"}' 2>&1 | grep "< HTTP"
# Expected: HTTP/2 200 (or 202)

# List artifacts uploaded for the current release
RELEASE="${SENTRY_RELEASE:-$(node -e "console.log(require('./package.json').version)")}"
echo "Checking release: $RELEASE"
sentry-cli releases files "$RELEASE" list

# Explain why a specific event has unresolved source maps
# Get the event ID from the Sentry issue detail page
sentry-cli sourcemaps explain \
  --org "$SENTRY_ORG" \
  --project "$SENTRY_PROJECT" \
  "EVENT_ID_HERE"

# Common output: "artifact ~/static/js/main.abc123.js not found"
# This means your url-prefix does not match the deployed URL path

# Dry-run upload to catch issues before they affect production
sentry-cli sourcemaps upload \
  --release="$RELEASE" \
  --url-prefix="~/static/js" \
  --validate \
  --dry-run \
  ./dist

# If using a bundler plugin, verify it sets the correct prefix:
# Webpack: devtool: 'source-map' (not 'eval-source-map')
# Vite: build.sourcemap: true

// Verify propagation headers are being sent
// In your HTTP client (axios, fetch, etc.), log outbound headers:

import * as Sentry from '@sentry/node';

// Check: does the active span exist when the outbound call happens?
const activeSpan = Sentry.getActiveSpan();
if (!activeSpan) {
  console.error('No active span at the point of outbound HTTP call');
  console.error('The call must happen INSIDE a Sentry.startSpan() callback');
}

// Manually propagate if auto-instrumentation is not working
const headers: Record<string, string> = {};
Sentry.getClient()?.getOptions().tracePropagationTargets; // check targets
console.log('tracePropagationTargets:',
  Sentry.getClient()?.getOptions().tracePropagationTargets ?? 'default (all)');

// Verify: the downstream service must extract these headers
// sentry-trace: <traceId>-<spanId>-<sampled>
// baggage: sentry-environment=production,sentry-release=1.0.0,...

// Fix: ensure tracePropagationTargets includes the downstream URL
Sentry.init({
  dsn: process.env.SENTRY_DSN,
  tracesSampleRate: 1.0,
  // Only propagate to your own services — never to third-party APIs
  tracePropagationTargets: [
    'localhost',
    /^https:\/\/api\.yourapp\.com/,
    /^https:\/\/internal\./,
  ],
});

// Diagnosis: check breadcrumb count over time
setInterval(() => {
  const scope = Sentry.getCurrentScope();
  // @ts-expect-error — accessing internal for diagnosis only
  const breadcrumbs = scope._breadcrumbs?.length ?? 'unknown';
  const mem = process.memoryUsage();
  console.log('[Sentry Health]', {
    breadcrumbs,
    heapUsed: `${(mem.heapUsed / 1024 / 1024).toFixed(1)} MB`,
    rss: `${(mem.rss / 1024 / 1024).toFixed(1)} MB`,
  });
}, 60_000);

// Fix: cap breadcrumbs and disable noisy auto-breadcrumbs
Sentry.init({
  dsn: process.env.SENTRY_DSN,
  maxBreadcrumbs: 20, // Default is 100 — reduce for long-running processes
  integrations: [
    // Disable console breadcrumbs if they flood the buffer
    Sentry.consoleIntegration({ levels: ['error', 'warn'] }),
  ],
});