Prometheus ve Grafana ile Sunucu Monitoring Rehberi

Prometheus ve Grafana, modern altyapı monitoring'inin temel araçlarıdır. Bu rehberde kapsamlı bir monitoring sistemi kurmayı öğreneceksiniz.

Prometheus Nedir?

Prometheus, time-series veritabanı tabanlı bir monitoring ve alerting sistemidir:

• Pull-based: Hedeflerden metrik çeker
• Multi-dimensional: Label tabanlı veri modeli
• PromQL: Güçlü sorgulama dili
• Alerting: Entegre alert yönetimi
• Service discovery: Otomatik hedef keşfi

Prometheus Kurulumu

# İndirme
wget https://github.com/prometheus/prometheus/releases/download/v2.48.0/prometheus-2.48.0.linux-amd64.tar.gz
tar xvfz prometheus-*.tar.gz
cd prometheus-*

# Yapılandırma
cat > prometheus.yml <<EOF
global:
  scrape_interval: 15s

scrape_configs:
  - job_name: 'prometheus'
    static_configs:
      - targets: ['localhost:9090']

  - job_name: 'node'
    static_configs:
      - targets: ['localhost:9100']
EOF

# Başlat
./prometheus --config.file=prometheus.yml

Systemd Service

# /etc/systemd/system/prometheus.service
[Unit]
Description=Prometheus
After=network.target

[Service]
User=prometheus
ExecStart=/usr/local/bin/prometheus \
    --config.file=/etc/prometheus/prometheus.yml \
    --storage.tsdb.path=/var/lib/prometheus \
    --web.listen-address=:9090
Restart=always

[Install]
WantedBy=multi-user.target

Node Exporter

Sunucu metriklerini toplamak için Node Exporter kurulumu:

# İndirme
wget https://github.com/prometheus/node_exporter/releases/download/v1.7.0/node_exporter-1.7.0.linux-amd64.tar.gz
tar xvfz node_exporter-*.tar.gz

# Başlat
./node_exporter

# Systemd service
[Unit]
Description=Node Exporter
After=network.target

[Service]
User=node_exporter
ExecStart=/usr/local/bin/node_exporter
Restart=always

[Install]
WantedBy=multi-user.target

Prometheus Yapılandırması

# prometheus.yml
global:
  scrape_interval: 15s
  evaluation_interval: 15s

alerting:
  alertmanagers:
    - static_configs:
        - targets: ['localhost:9093']

rule_files:
  - "rules/*.yml"

scrape_configs:
  - job_name: 'prometheus'
    static_configs:
      - targets: ['localhost:9090']

  - job_name: 'node'
    static_configs:
      - targets:
          - 'server1:9100'
          - 'server2:9100'
          - 'server3:9100'
        labels:
          env: 'production'

  - job_name: 'nginx'
    static_configs:
      - targets: ['localhost:9113']

PromQL Sorguları

# CPU kullanımı
100 - (avg by(instance) (rate(node_cpu_seconds_total{mode="idle"}[5m])) * 100)

# Bellek kullanımı
(1 - (node_memory_MemAvailable_bytes / node_memory_MemTotal_bytes)) * 100

# Disk kullanımı
(1 - (node_filesystem_avail_bytes / node_filesystem_size_bytes)) * 100

# Network I/O
rate(node_network_receive_bytes_total[5m])
rate(node_network_transmit_bytes_total[5m])

# HTTP istek oranı
rate(http_requests_total[5m])

# Hata oranı
sum(rate(http_requests_total{status=~"5.."}[5m])) / sum(rate(http_requests_total[5m]))

Alert Rules

# rules/alerts.yml
groups:
  - name: node_alerts
    rules:
      - alert: HighCPUUsage
        expr: 100 - (avg by(instance) (rate(node_cpu_seconds_total{mode="idle"}[5m])) * 100) > 80
        for: 5m
        labels:
          severity: warning
        annotations:
          summary: "High CPU usage on {{ $labels.instance }}"
          description: "CPU usage is above 80% for 5 minutes"

      - alert: HighMemoryUsage
        expr: (1 - (node_memory_MemAvailable_bytes / node_memory_MemTotal_bytes)) * 100 > 90
        for: 5m
        labels:
          severity: critical
        annotations:
          summary: "High memory usage on {{ $labels.instance }}"

      - alert: DiskSpaceLow
        expr: (1 - (node_filesystem_avail_bytes / node_filesystem_size_bytes)) * 100 > 85
        for: 10m
        labels:
          severity: warning
        annotations:
          summary: "Disk space low on {{ $labels.instance }}"

Grafana Kurulumu

# Ubuntu/Debian
sudo apt-get install -y apt-transport-https software-properties-common
wget -q -O - https://packages.grafana.com/gpg.key | sudo apt-key add -
echo "deb https://packages.grafana.com/oss/deb stable main" | sudo tee /etc/apt/sources.list.d/grafana.list
sudo apt-get update
sudo apt-get install grafana

# Başlat
sudo systemctl enable grafana-server
sudo systemctl start grafana-server

# Erişim: http://localhost:3000
# Default: admin/admin

Grafana Datasource

1. Configuration > Data Sources
2. Add data source > Prometheus
3. URL: http://localhost:9090
4. Save & Test

Dashboard Oluşturma

Grafana panellerinde kullanılabilecek sorgular:

# CPU Panel
100 - (avg by(instance) (rate(node_cpu_seconds_total{mode="idle"}[5m])) * 100)

# Memory Panel
node_memory_MemTotal_bytes - node_memory_MemAvailable_bytes

# Disk I/O Panel
rate(node_disk_read_bytes_total[5m])
rate(node_disk_written_bytes_total[5m])

# Network Panel
rate(node_network_receive_bytes_total{device="eth0"}[5m])
rate(node_network_transmit_bytes_total{device="eth0"}[5m])

Hazır Dashboardlar

Grafana Dashboard ID'leri (Import ile):

• Node Exporter Full: 1860
• Node Exporter Quickstart: 11074
• Nginx: 9614
• MySQL: 7362
• PostgreSQL: 9628

Sonuç

Prometheus ve Grafana kombinasyonu, altyapınızı görselleştirmek ve proaktif monitoring yapmak için mükemmel bir çözümdür. Alert yapılandırması ile sorunları erkenden tespit edebilirsiniz.