common-observability

name	common-observability
description	Standards for structured logging, distributed tracing, and metrics. (triggers: **/*.service.ts, **/*.handler.ts, **/*.middleware.ts, **/*.interceptor.ts, **/*.go, **/*.java, **/*.kt, **/*.py, logging, tracing, metrics, opentelemetry, observability, slo)

Common Observability Standards

Priority: P1 (OPERATIONAL)

📋 Logging & Tracing

• JSON Logs: Always emit JSON structured logs. Never plain-text in prod.
• Correlation: Extract X-Request-Id or traceparent. Attach to async context.
• Tracing: Use OpenTelemetry. Propagate W3C traceparent.
• Spans: Name spans like <HTTP_METHOD> <route> (GET /users/:id).

📊 Metrics

• Required: Request rate, Error rate, Latency histogram (p50/p95/p99), Saturation.
• SLOs: Alert on SLO burn rates, not raw threshold spikes.

🚫 Anti-Patterns

• Console.log: Do not use in prod; use a structured logger (pino, zap).
• PII in Logs: Never log tokens, passwords, or full request bodies.
• Dynamic Span Names: GET /users/123 causes cardinality explosion. Use GET /users/:id.
• Missing Cleanup: Always end tracing spans.

References

• Observability Data Formats