As33
@periodic/
arsenic
stable_latency
ℹ️ Info

Consistent performance across executions

Low-variance execution time indicates well-optimized query execution and stable system conditions.

Using stable latency as a baseline

typescript
// stable_latency fires when variance is low across recent executions.
// Use it to establish performance baselines and detect regressions.

const monitor = createMonitor({
  emitPositiveSignals: true,
  exporter: (event) => {
    if (event.signals.includes('stable_latency')) {
      // Record the p50 as your baseline
      metrics.gauge('db.query.baseline_ms', event.durationMs, {
        model: event.model,
        operation: event.operation,
      });
    }
    if (event.signals.includes('high_variance_latency')) {
      // Alert when the same query stops being stable
      alertOncall('Latency regression detected', {
        model: event.model,
        durationMs: event.durationMs,
      });
    }
  },
});