Overview

Observability is the ability to understand a system's internal state from its external outputs. The three pillars of observability are metrics, logs, and traces.

Topics

Logging

Structured logging and log aggregation

Monitoring & Metrics

System metrics and alerting

Distributed Tracing

Request tracing across services

The Three Pillars

┌─────────────────────────────────────────────────────────┐
│                    Observability                         │
├──────────────────┬──────────────────┬───────────────────┤
│      Logs        │     Metrics      │     Traces        │
│  (What happened) │  (How much)      │  (Request flow)   │
├──────────────────┼──────────────────┼───────────────────┤
│  Events          │  Counters        │  Spans            │
│  Errors          │  Gauges          │  Context          │
│  Debug info      │  Histograms      │  Latency          │
└──────────────────┴──────────────────┴───────────────────┘

Why Observability Matters

Benefit	Description
Debugging	Find root cause of issues
Performance	Identify bottlenecks
Reliability	Detect and alert on failures
Capacity	Plan for growth
Business	Track KPIs and SLOs

Observability