| name | NestJS Observability |
|---|---|
| description | Structured logging (Pino) and Prometheus metrics. |
| metadata | {"labels": ["nestjs", "logging", "monitoring", "pino"], "triggers": {"files": ["main.ts", "**/*.module.ts"], "keywords": ["nestjs-pino", "Prometheus", "Logger", "reqId"]}} |
Observability Standards
Priority: P1 (OPERATIONAL)
Logging, monitoring, and observability patterns for production applications.
- Standard: Use
nestjs-pinofor high-performance JSON logging. - Why: Node's built-in
console.logis blocking and unstructured. - Configuration:
- Redaction: Mandatory masking of sensitive fields (
password,token,email). - Context: Always inject
Loggerand set the context (LoginService).
Tracing (Correlation)
- Request ID: Every log line must include a
reqId(Request ID). nestjs-pinohandles this automatically usingAsyncLocalStorage.- Propagation: Pass
x-request-idto downstream microservices/database queries key to trace flows.
Metrics
- Exposure: Use
@willsoto/nestjs-prometheusto expose/metricsfor Prometheus scraping. - Key Metrics:
1.
http_request_duration_seconds(Histogram) 2.db_query_duration_seconds(Histogram) 3.memory_usage_bytes(Gauge)
Health Checks
- Terminus: Implement explicit logic for "Liveness" (I'm alive) vs "Readiness" (I can take traffic).
- DB Check:
TypeOrmHealthIndicator/PrismaHealthIndicator. - Memory Check: Fail if Heap > 300MB (prevent crash loops).