Glean Observability

Overview

Glean aggregates enterprise knowledge across dozens of connectors, making indexing health and search quality the two pillars of observability. Monitor connector sync status to catch stale content before users notice, track search latency to maintain sub-second responses, and measure zero-result rates to identify coverage gaps. Degraded indexing silently erodes search relevance, so proactive alerting is essential.

Key Metrics

| Metric | Type | Target | Alert Threshold | |--------|------|--------|-----------------| | Search latency p95 | Histogram | < 400ms | > 1s | | Zero-result query rate | Gauge | < 5% | > 10% | | Documents indexed per run | Counter | Stable +/-5% | Drop > 20% | | Connector sync errors | Counter | 0 | > 3 per hour | | Stale content ratio | Gauge | < 10% | > 25% (>30 days old) | | Indexing throughput | Gauge | > 1000 docs/min | < 500 docs/min |

Instrumentation

typescript
async function trackGleanSearch(query: string, client: GleanClient) {
  const start = Date.now();
  try {
    const results = await client.search({ query });
    const latency = Date.now() - start;
    metrics.histogram('glean.search.latency', latency);
    metrics.increment('glean.search.total');
    if (results.totalCount === 0) metrics.increment('glean.search.zero_results');
    return results;
  } catch (err) {
    metrics.increment('glean.search.errors', { error: err.code });
    throw err;
  }
}

Health Check Dashboard

typescript
async function gleanHealth(): Promise<Record<string, string>> {
  const connectors = await gleanAdmin.getConnectorStatus();
  const staleRatio = await gleanAdmin.getStaleContentRatio(30);
  const searchP95 = await metrics.query('glean.search.latency', 'p95', '5m');
  return {
    connectors: connectors.every(c => c.status === 'ok') ? 'healthy' : 'degraded',
    content_freshness: staleRatio < 0.1 ? 'healthy' : 'stale',
    search_latency: searchP95 < 400 ? 'healthy' : 'slow',
  };
}

Alerting Rules

typescript
const alerts = [
  { metric: 'glean.search.latency_p95', condition: '> 1000ms', window: '10m', severity: 'warning' },
  { metric: 'glean.search.zero_result_rate', condition: '> 0.10', window: '1h', severity: 'warning' },
  { metric: 'glean.indexing.sync_errors', condition: '> 3', window: '1h', severity: 'critical' },
  { metric: 'glean.indexing.doc_count_delta', condition: 'drop > 20%', window: '1d', severity: 'critical' },
];

Structured Logging

typescript
function logGleanEvent(event: string, data: Record<string, any>) {
  console.log(JSON.stringify({
    service: 'glean', event,
    connector: data.connector, doc_count: data.docCount,
    query: data.query ? data.query.substring(0, 100) : undefined,
    latency_ms: data.latency, result_count: data.resultCount,
    timestamp: new Date().toISOString(),
  }));
}

Error Handling

| Signal | Meaning | Action | |--------|---------|--------| | Connector sync failure | Source API down or creds expired | Check connector config, rotate tokens | | Zero-result spike | Missing content or bad query parsing | Audit indexed sources, check synonyms | | Indexing doc count drop | Source deletion or API pagination bug | Compare source counts, review API logs | | Search latency > 1s | Overloaded cluster or complex queries | Check Glean status page, review query patterns |

Resources

• Glean Developer Portal
• Indexing API
• Search API

Next Steps

See glean-incident-runbook.