- name
- Monitoring
- description
- Set up observability for applications and infrastructure with metrics, logs, traces, and alerts.
Complexity Levels
| Level | Tools | Setup Time | Best For |
|---|---|---|---|
| Minimal | UptimeRobot, Healthchecks.io | 15 min | Side projects, MVPs |
| Standard | Uptime Kuma, Sentry, basic Grafana | 1-2 hours | Small teams, startups |
| Professional | Prometheus, Grafana, Loki, Alertmanager | 1-2 days | Production systems |
| Enterprise | Datadog, New Relic, or full OSS stack | Ongoing | Large-scale operations |
The Three Pillars
| Pillar | What It Answers | Tools |
|---|---|---|
| Metrics | "How is the system performing?" | Prometheus, Grafana, Datadog |
| Logs | "What happened?" | Loki, ELK, CloudWatch |
| Traces | "Why is this request slow?" | Jaeger, Tempo, Sentry |
Quick Start by Use Case
"I just want to know if it's down" → UptimeRobot (free) or Uptime Kuma (self-hosted). See simple.md.
"I need to debug production errors" → Sentry with your framework SDK. 5-minute setup. See apm.md.
"I want real observability" → Prometheus + Grafana + Loki. See prometheus.md.
"I need to centralize logs" → Loki for simple, ELK for complex queries. See logs.md.
What to Monitor
Applications (RED Method)
- Rate — requests per second
- Errors — error rate by endpoint
- Duration — latency (p50, p95, p99)
Infrastructure (USE Method)
- Utilization — CPU, memory, disk usage
- Saturation — queue depth, load average
- Errors — hardware/system errors
Alerting Principles
| Do | Don't |
|---|---|
| Alert on symptoms (user impact) | Alert on causes (CPU high) |
| Include runbook link | Require investigation to understand |
| Set appropriate severity | Make everything P1 |
| Require action | Alert on "interesting" metrics |
Alert fatigue kills monitoring. If alerts are ignored, you have no monitoring.
For alert configuration, severities, and on-call setup, see alerting.md.
Cost Comparison
| Solution | Monthly Cost (small) | Monthly Cost (medium) |
|---|---|---|
| UptimeRobot | Free | $7 |
| Uptime Kuma | $5 (VPS) | $5 (VPS) |
| Sentry | Free / $26 | $80 |
| Grafana Cloud | Free tier | $50+ |
| Datadog | $15/host | $23/host + features |
| Self-hosted stack | $10-20 (VPS) | $50-100 (VPS) |
Common Mistakes
- Starting with Prometheus/Grafana when Uptime Kuma would suffice
- No alerting (dashboards nobody watches)
- Too many alerts (alert fatigue → ignored)
- Missing runbooks (alert fires, nobody knows what to do)
- Not monitoring from outside (only internal checks)
- Storing logs forever (cost explodes)