European CDN Network

Project Overview

A content delivery network (CDN) solution built exclusively with European infrastructure to address the growing demand for data sovereignty while maintaining world-class performance.

The Challenge

Existing CDNs present challenges for European organizations:

• Global POPs: Data may leave EU borders
• US-based companies: Subject to CLOUD Act
• Limited control: Black-box infrastructure
• Compliance complexity: Difficult to audit data flows

Our Approach

Built a CDN using only European providers and open-source software:

Infrastructure

• Edge Locations: 12 POPs across Europe
• Origin Servers: Hetzner dedicated servers in Germany
• DNS: European DNS providers with GeoDNS
• SSL/TLS: Let’s Encrypt with automated renewal
• Software: Nginx + Varnish + custom caching layer

Geographic Distribution

Location	Provider	Purpose
Frankfurt, DE	Hetzner	Origin + Edge
Paris, FR	Scaleway	Edge
Amsterdam, NL	Hetzner	Edge
Warsaw, PL	OVH	Edge
Milan, IT	Aruba	Edge
London, UK	OVH	Edge
Stockholm, SE	Bahnhof	Edge

Architecture

Edge Node Configuration

# Nginx configuration for edge nodes
upstream origin_servers {
    least_conn;
    server origin1.eu-central.example.com:443 max_fails=3;
    server origin2.eu-central.example.com:443 max_fails=3;

    # Health check
    check interval=3000 rise=2 fall=3 timeout=2000;
}

server {
    listen 443 ssl http2;
    server_name cdn.example.com;

    # EU-only SSL certificates
    ssl_certificate /etc/letsencrypt/live/cdn.example.com/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/cdn.example.com/privkey.pem;

    # Modern SSL configuration
    ssl_protocols TLSv1.2 TLSv1.3;
    ssl_ciphers 'ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256';

    # Cache configuration
    location / {
        proxy_pass https://origin_servers;
        proxy_cache cdn_cache;
        proxy_cache_valid 200 7d;
        proxy_cache_valid 404 1h;

        # Add compliance headers
        add_header X-Data-Region "EU" always;
        add_header X-Cache-Status $upstream_cache_status;
    }
}

Intelligent Routing

Custom DNS routing based on user location and origin compliance:

# GeoDNS routing logic
def get_nearest_pop(user_ip: str, compliance_level: str) -> str:
    location = geoip.lookup(user_ip)

    if compliance_level == "strict":
        # Only route to POPs in user's country
        return pops.get_in_country(location.country)

    # Route to nearest POP within EU
    return pops.get_nearest_eu(location.coordinates)

Caching Strategy

# Cache key generation with compliance awareness
def generate_cache_key(request):
    base_key = f"{request.url}:{request.method}"

    # Include user country for compliance
    if request.data_residency_required:
        country = geoip.lookup(request.ip).country
        base_key += f":country-{country}"

    return hashlib.sha256(base_key.encode()).hexdigest()

Performance Results

Compared to global CDNs for European users:

Latency Improvements

Region	Global CDN	European CDN	Improvement
Germany	45ms	12ms	73%
France	52ms	18ms	65%
Poland	78ms	25ms	68%
Italy	65ms	22ms	66%
Spain	71ms	28ms	61%

Throughput

• Average: 850 Mbps per POP
• Peak: 1.2 Gbps
• Cache Hit Ratio: 94.2%
• Origin Load Reduction: 18x

Compliance Features

Data Residency Guarantees

interface CompliancePolicy {
  allowedRegions: string[];
  encryptionRequired: boolean;
  auditLogging: boolean;
}

const policy: CompliancePolicy = {
  allowedRegions: ['DE', 'FR', 'NL', 'PL', 'IT', 'UK', 'SE'],
  encryptionRequired: true,
  auditLogging: true
};

// Enforce at routing layer
if (!policy.allowedRegions.includes(request.targetRegion)) {
  throw new ComplianceViolationError(
    `Region ${request.targetRegion} not allowed`
  );
}

Audit Trail

Every request is logged for compliance:

{
  "timestamp": "2024-06-10T14:23:45Z",
  "request_id": "req_abc123",
  "client_ip": "192.0.2.1",
  "client_country": "DE",
  "edge_pop": "frankfurt",
  "origin_hit": false,
  "cache_status": "HIT",
  "response_time_ms": 12,
  "data_remained_in_eu": true
}

Cost Analysis

Monthly Costs (for 10TB traffic)

• Global CDN: ~$1,200
• European CDN: ~$650
• Savings: 46%

Breakdown

Component	Monthly Cost
Edge Servers (12x)	$420
Origin Servers (2x)	$140
Bandwidth	$60
DNS	$15
Monitoring	$15
Total	$650

Security

DDoS Protection

# Rate limiting configuration
limit_req_zone $binary_remote_addr zone=general:10m rate=10r/s;
limit_req_zone $binary_remote_addr zone=api:10m rate=5r/s;

# Geo-blocking for suspicious regions
geo $blocked_region {
    default 0;
    # Block non-EU countries if needed
}

server {
    if ($blocked_region) {
        return 403;
    }

    location / {
        limit_req zone=general burst=20 nodelay;
        # ... rest of config
    }
}

WAF Integration

• ModSecurity rules
• OWASP Core Rule Set
• Custom rules for application protection

Monitoring

Real-time dashboard showing:

• Cache hit rates per POP
• Latency distribution
• Origin server health
• Bandwidth usage
• Compliance status (all data in EU)

# Prometheus metrics
- name: cdn_cache_hit_ratio
  help: Cache hit ratio per POP
  type: gauge

- name: cdn_request_duration_seconds
  help: Request latency distribution
  type: histogram

- name: cdn_origin_requests_total
  help: Requests forwarded to origin
  type: counter

Lessons Learned

What Worked

1. European providers: Excellent performance and support
2. Open source: Full control and transparency
3. GeoDNS: Intelligent routing crucial for compliance
4. Caching: Aggressive caching reduced origin load significantly

Challenges

1. Initial setup: More complex than using a SaaS CDN
2. Provider diversity: Maintaining relationships with multiple providers
3. Monitoring: Needed to build custom dashboards
4. Failover: Required careful testing of edge failure scenarios

Future Enhancements

• Add more POPs in Southern and Eastern Europe
• Implement edge computing capabilities
• Add real-time analytics at the edge
• Develop self-service customer portal
• Add video streaming optimization

Technical Stack

• Reverse Proxy: Nginx 1.24+
• Cache: Varnish 7.x
• DNS: PowerDNS with GeoIP module
• Monitoring: Prometheus + Grafana
• Deployment: Ansible playbooks
• SSL: Let’s Encrypt with certbot

Conclusion

Building a European CDN is not only possible but offers significant advantages for organizations with strict compliance requirements. The combination of European infrastructure providers and open-source software delivers performance that rivals global CDNs while ensuring complete data sovereignty.

Interested in implementing a similar solution? Let’s talk