Metrics

Chapter 36: Node Metrics & Prometheus

Overview

Monitoring your blockchain node is essential for maintaining performance, detecting issues, and ensuring uptime.

36.1 Why Monitor?

┌─────────────────────────────────────────────────────────────────┐
│                    MONITORING OBJECTIVES                         │
├─────────────────────────────────────────────────────────────────┤
│                                                                  │
│   1. PERFORMANCE                                                │
│      - Track sync progress                                      │
│      - Monitor resource usage                                   │
│                                                                  │
│   2. AVAILABILITY                                               │
│      - Detect node downtime                                     │
│      - Alert on failures                                        │
│                                                                  │
│   3. SECURITY                                                   │
│      - Detect unusual patterns                                  │
│      - Monitor access attempts                                   │
│                                                                  │
│   4. CAPACITY PLANNING                                          │
│      - Track storage growth                                      │
│      - Plan upgrades                                             │
│                                                                  │
└─────────────────────────────────────────────────────────────────┘

36.2 Enabling Metrics

Geth Metrics

# Enable metrics
geth --metrics --metrics.addr 0.0.0.0 --metrics.port 6060

Metrics Endpoint

http://localhost:6060/debug/metrics
http://localhost:6060/debug/metrics/prometheus

36.3 Key Metrics to Track

Sync Metrics

Metric	Description
`eth_block_number`	Current block height
`eth_head_header`	Latest header number
`eth_syncing`	Sync progress

Performance Metrics

Metric	Description
`process_cpu_seconds`	CPU usage
`process_memory`	Memory usage
`node_disk_io`	Disk I/O

Network Metrics

Metric	Description
`p2p_peers`	Number of connected peers
`p2p_dial_connections`	Outgoing connections
`p2p_recv_messages`	Messages received

36.4 Prometheus Configuration

Install Prometheus

# Download
wget https://github.com/prometheus/prometheus/releases/download/v2.45.0/prometheus-2.45.0.linux-amd64.tar.gz

# Extract
tar xzf prometheus-2.45.0.linux-amd64.tar.gz

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

prometheus.yml

global:
  scrape_interval: 15s

scrape_configs:
  - job_name: 'geth'
    static_configs:
      - targets: ['localhost:6060']

36.5 Grafana Dashboards

Import Dashboard

Install Grafana
Add Prometheus data source
Import dashboard:
- Ethereum: Dashboard ID 14611
- Generic: Create custom

Key Dashboards

Dashboard	Description
Block Production	Block times, empty blocks
Node Health	CPU, memory, disk
Network	Peers, transaction pool
Consensus	Validator performance

36.6 Alerting

Prometheus Alerts

groups:
  - name: geth-alerts
    rules:
      - alert: NodeDown
        expr: up{job="geth"} == 0
        for: 5m
        labels:
          severity: critical
        annotations:
          summary: "Geth node is down"

      - alert: NoPeers
        expr: p2p_peers == 0
        for: 5m
        labels:
          severity: warning

      - alert: SyncStalled
        expr: eth_syncing == true
        for: 30m
        labels:
          severity: warning

Summary

Enable metrics with --metrics flag
Track sync, performance, and network metrics
Use Prometheus + Grafana for monitoring
Set up alerts for critical issues

Next Chapter

In Chapter 37: Logging & Log Management, we’ll explore logging.

Last Updated: 2026-02-20