INTERMEDIATE // MULTI LAYER STACKING
MODULE 08 // OBSERVABILITY

Stack Monitoring.

Monitor multi-layer stack health and performance for operational excellence.

MONITORING STRATEGY

Monitor each layer independently and the stack as a whole. Layer-level metrics identify individual performance issues; stack-level metrics reveal systemic problems and layer interactions.

Key layer metrics: latency (P50, P95, P99), error rate, score distribution, and availability. Key stack metrics: end-to-end latency, fusion score distribution, decision distribution, and cross-layer correlation.

Alert on anomalies, not just thresholds. A layer's P95 latency might be 'normal' at 200ms, but a sudden jump from 100ms baseline indicates problems. Use anomaly detection for intelligent alerting.

LAYER HEALTH

Monitor individual layer latency, errors, and availability. Alert on degradation before it impacts stack.

STACK PERFORMANCE

Track end-to-end latency and decision throughput. Identify bottlenecks across the full stack.

DECISION ANALYTICS

Monitor decision distribution: approval/challenge/block rates. Detect shifts indicating attacks or misconfig.

CROSS-LAYER CORRELATION

Analyze how layers correlate. Disagreement between layers may indicate attacks or layer issues.

KNOWLEDGE CHECK // Q08
Why is cross-layer correlation monitoring important?