| name | std-monitoring |
| description | Monitoring/observability standards — structured logs with request_id, no sensitive data, health checks, CloudWatch alarms, Sentry. Use when adding logging, jobs, or controllers. |
| paths | ["**/app/jobs/**/*.rb","**/app/controllers/**/*.rb","**/config/initializers/**/*.rb","**/*.tf","**/docker-compose*.yml","**/.github/workflows/**"] |
Monitoring & Observability Standards
Enforcement: code-reviewer skill (Step 8: Stack-Specific Checks), devops-engineer agent (Step 8: Configure Monitoring), deploy skill (Step 7: Monitoring).
Structured Logging
- Use lograge gem for Rails to produce structured JSON logs
- Every log entry must include: timestamp, level, request_id, user_id, action
- Never log sensitive data (passwords, tokens, PII)
- Use log levels consistently: DEBUG for dev, INFO for requests, WARN for recoverable issues, ERROR for failures
Request Tracing
- You do not build this — Rails already does.
ActionDispatch::RequestId is in the default
middleware stack: it adopts an incoming X-Request-Id (typically set by the load balancer, so
your logs join to the LB's for free) or generates a uuid, exposes it as request.request_id,
and returns it to the client in the X-Request-Id header.
config.log_tags = [:request_id] — one line, and every log line in the request carries it.- Include request_id in all log entries, error reports, and API responses.
- The trace breaks at the async boundary. A Sidekiq job runs in another process with no
request:
request_id is nil there unless you propagate it through client/server middleware.
That is exactly where you need it — the async work is what fails at 3am.
- Centrifugo messages must carry request_id for end-to-end tracing.
- The id is outside input (Rails sanitizes it to 255 alphanumeric-and-dash chars because a
client can send it) — never interpolate it into SQL or a shell command.
- Deep guide →
references/request-tracing.md
Health Check Endpoints
/health — application liveness (returns 200 if app process is running)/health/db — database connectivity (PostgreSQL/PostGIS query check)/health/redis — Redis connectivity and latency check/health/centrifugo — Centrifugo WebSocket server availability- All health checks must respond within 5 seconds or return 503
Key Metrics
- Request rate (requests/second by endpoint)
- Error rate (4xx and 5xx by endpoint)
- Latency percentiles: p50, p95, p99
- Sidekiq: queue depth, job execution time, retry count, dead jobs
- Database: active connections, query duration, slow queries (>100ms)
- Redis: memory usage, hit rate, connection count
CloudWatch Alarms
- ECS task health: alarm if running tasks < desired tasks for >2 minutes
- RDS connections: alarm if connections > 80% of max
- ElastiCache memory: alarm if memory usage > 75%
- Error rate spikes: alarm if 5xx rate > 1% for >5 minutes
- Sidekiq dead jobs: alarm if dead job count increases
Centrifugo Monitoring
- Track active WebSocket connection count
- Monitor message throughput (messages/second)
- Track channel count and subscriptions per channel
- Alert on connection drops or message delivery failures
- Monitor Centrifugo process memory and CPU usage
Error Tracking
- Sentry for both Rails backend and React Native mobile
- Configure source maps for React Native for readable stack traces
- Set up release tracking to correlate errors with deployments
- Tag errors with: environment, user_id, device_info (mobile), request_id
Grafana Dashboards
- Overview dashboard: request rate, error rate, latency, active users
- Infrastructure dashboard: ECS, RDS, ElastiCache, Centrifugo metrics
- Background jobs dashboard: Sidekiq queues, execution times, failures
- Mobile dashboard: crash-free rate, API latency from client, active sessions
Deep guides (read on demand, do not preload)
- Where
request_id comes from (ActionDispatch::RequestId), config.log_tags, Current
attributes for services, propagating the id into Sidekiq (the boundary where the trace
breaks), returning it to clients, and proving it end to end with one curl
→ references/request-tracing.md
Related, owned elsewhere — do not duplicate: querying the logs this produces (Logs Insights,
gcloud logging read) → ../log-search; the API error envelope the id belongs in →
../std-api-design/references/errors-rails.md; what must never be logged → ../std-security.
