====== Runbook: Prometheus ======

<WRAP round info>
**Trajanje:** ~15 minut \\
**Vloga:** DevOps, SRE \\
**Predpogoj:** Prometheus strežnik, Gateway deluje
</WRAP>

Zbiranje metrik iz Data Gateway s Prometheus.

----

===== Potek dela =====

<mermaid>
flowchart TD
    A[Začetek] --> B[Aktiviraj metrike]
    B --> C[Prometheus konfiguracija]
    C --> D[Dodaj Scrape-Job]
    D --> E[Prometheus reload]
    E --> F[Preveri cilje]
    F --> G{Aktiven?}
    G -->|Da| H[Končano]
    G -->|Ne| I[Preveri požarni zid/končno točko]

    style H fill:#e8f5e9
    style I fill:#ffebee
</mermaid>

----

===== 1. Aktiviranje metrik v Gateway =====

**appsettings.json:**

<code json>
{
  "Metrics": {
    "Enabled": true,
    "Endpoint": "/metrics"
  }
}
</code>

**Ali prek NuGet (če ni vgrajeno):**

<code bash>
# prometheus-net.AspNetCore
dotnet add package prometheus-net.AspNetCore
</code>

**Program.cs:**

<code csharp>
// Metrics Middleware
app.UseHttpMetrics();
app.MapMetrics(); // /metrics končna točka
</code>

----

===== 2. Testiranje končne točke metrik =====

<code bash>
curl http://localhost:5000/metrics

# Pričakovan izpis (Prometheus oblika):
# HELP http_requests_total Total HTTP requests
# TYPE http_requests_total counter
# http_requests_total{method="GET",endpoint="/api/v1/dsn/demo/tables",status="200"} 42
</code>

----

===== 3. Konfiguracija Prometheus =====

**/etc/prometheus/prometheus.yml:**

<code yaml>
global:
  scrape_interval: 15s
  evaluation_interval: 15s

scrape_configs:
  # Data Gateway
  - job_name: 'data-gateway'
    static_configs:
      - targets: ['gateway.example.com:5000']
    metrics_path: /metrics
    scheme: http  # ali https

  # Več instanc
  - job_name: 'data-gateway-cluster'
    static_configs:
      - targets:
          - 'gateway-1.example.com:5000'
          - 'gateway-2.example.com:5000'
          - 'gateway-3.example.com:5000'
</code>

----

===== 4. Ponovno nalaganje Prometheus =====

<code bash>
# Config-Reload (brez ponovnega zagona)
curl -X POST http://localhost:9090/-/reload

# Ali ponovni zagon
sudo systemctl restart prometheus
</code>

----

===== 5. Preverjanje ciljev =====

**Spletni vmesnik:** ''http://prometheus:9090/targets''

Ali prek API:

<code bash>
curl -s http://localhost:9090/api/v1/targets | jq '.data.activeTargets[] | {job: .labels.job, health: .health}'
</code>

**Pričakovan izpis:**

<code json>
{
  "job": "data-gateway",
  "health": "up"
}
</code>

----

===== 6. Pomembne poizvedbe =====

**PromQL primeri:**

<code>
# Stopnja zahtev (na sekundo)
rate(http_requests_total{job="data-gateway"}[5m])

# Povprečni odzivni čas
rate(http_request_duration_seconds_sum{job="data-gateway"}[5m])
/
rate(http_request_duration_seconds_count{job="data-gateway"}[5m])

# Stopnja napak (5xx)
sum(rate(http_requests_total{job="data-gateway",status=~"5.."}[5m]))
/
sum(rate(http_requests_total{job="data-gateway"}[5m]))

# Poraba pomnilnika
process_resident_memory_bytes{job="data-gateway"}

# Aktivne povezave
http_requests_in_progress{job="data-gateway"}
</code>

----

===== 7. Kontrolni seznam =====

| # | Točka preverjanja | V |
|---|-----------|---|
| 1 | Končna točka metrik aktivirana | |
| 2 | /metrics dosegljiv | |
| 3 | Prometheus konfiguracija posodobljena | |
| 4 | Prometheus ponovno naložen | |
| 5 | Cilj "up" v Prometheus | |
| 6 | Metrike vidne v Grafana | |

----

===== Odpravljanje težav =====

| Težava | Vzrok | Rešitev |
|---------|---------|--------|
| Cilj "down" | Končna točka ni dosegljiva | Požarni zid, URL preveri |
| ''connection refused'' | Gateway ne deluje | Zaženi Gateway |
| ''404 Not Found'' | Metrike niso aktivirane | Preveri appsettings.json |
| Brez metrik | Napačna pot | Preveri ''metrics_path'' |

----

===== Kubernetes ServiceMonitor =====

Za Prometheus Operator:

<code yaml>
apiVersion: monitoring.coreos.com/v1
kind: ServiceMonitor
metadata:
  name: data-gateway
  namespace: monitoring
  labels:
    release: prometheus
spec:
  selector:
    matchLabels:
      app: data-gateway
  namespaceSelector:
    matchNames:
      - data-gateway
  endpoints:
    - port: http
      path: /metrics
      interval: 15s
</code>

----

===== Povezani Runbooks =====

  * [[.:grafana-dashboard|Grafana nadzorna plošča]] - Vizualizacija
  * [[.:alerting|Opozarjanje]] - Obvestila
  * [[..:automatisierung:kubernetes|Kubernetes]] - K8s namestitev

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<< [[.:start|<- Nadzor]] | [[.:grafana-dashboard|-> Grafana nadzorna plošča]] >>

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//Wolfgang van der Stille @ EMSR DATA d.o.o. - Data Gateway Professional//

{{tag>operator runbook prometheus metrics monitoring}}