The three pillars of observability are…
Options
- CPU, RAM, disk
- Logs, metrics, traces (Correct option)
- Unit, integration, E2E tests
- Dev, staging, prod
Answer
Logs, metrics, traces
Why
- Metrics: numbers over time (requests per second, error rate, latency). They tell you THAT something is wrong and trigger alerts.
- Traces: the path of one request across services, with timing per step. They show WHERE the time or error is.
- Logs: detailed text events. They tell you WHY.
OpenTelemetry is the common standard to produce all three.
Remember
Metrics = that, traces = where, logs = why.