Nginx Technology Intelligence

What is Nginx?

Nginx (pronounced "engine-x") is a high-performance web server, reverse proxy, and load balancer created by Igor Sysoev in 2004. Originally built to handle the C10K problem (10,000+ concurrent connections), Nginx now powers over 34% of websites including high-traffic sites like Netflix, Airbnb, and Dropbox.

Unlike Apache's process/thread-per-connection model, Nginx uses an asynchronous, event-driven architecture. A single worker process handles thousands of connections simultaneously, using minimal memory. This efficiency makes Nginx the preferred choice for high-traffic websites and microservices architectures.

F5 Networks acquired Nginx Inc. in 2019 for $670 million. Nginx remains open-source while Nginx Plus offers commercial features including active health checks, session persistence, and advanced monitoring.

Nginx Architecture

Event-Driven: Master process spawns worker processes. Each worker handles thousands of connections via epoll (Linux), kqueue (BSD), or IOCP (Windows). Non-blocking I/O maximizes throughput.

Reverse Proxy: Nginx excels as a frontend proxy. SSL termination, load balancing, caching, and compression at the edge. Backends focus on application logic.

Load Balancing: Round-robin, least connections, IP hash, and weighted distribution. Health checks remove failed backends. Session persistence for stateful apps.

Static Content: Extremely efficient static file serving. sendfile() system call bypasses user space. Proper caching headers maximize browser and CDN caching.

HTTP/2 & HTTP/3: Full HTTP/2 support including server push. Experimental HTTP/3 (QUIC) support. Modern protocol optimization.

Configuration Syntax: Declarative block-based configuration. Contexts: http, server, location, upstream. Changes require reload (nginx -s reload).

Nginx Use Cases

Reverse Proxy: Frontend for Node.js, Python (Gunicorn/uWSGI), Ruby (Puma), and Java applications. SSL termination and static file serving at Nginx layer.

Load Balancer: Distribute traffic across application server clusters. Health checks ensure requests reach healthy backends. Zero-downtime deployments.

API Gateway: Route API requests to microservices. Rate limiting, authentication, and request transformation. Nginx Plus adds JWT validation.

Static Content CDN: High-performance static file serving for images, CSS, JavaScript. Often paired with upstream CDNs (Cloudflare, Fastly).

WordPress Caching: FastCGI caching for WordPress. Serve cached pages without touching PHP. Dramatically reduces server load.

Kubernetes Ingress: Nginx Ingress Controller is the default Kubernetes ingress. Routes external traffic to cluster services.

Nginx Configuration Examples

Reverse Proxy to Node.js

upstream nodejs {
    server 127.0.0.1:3000;
    server 127.0.0.1:3001;
    keepalive 64;
}

server {
    listen 80;
    server_name example.com;
    return 301 https://$server_name$request_uri;
}

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

    ssl_certificate /etc/ssl/certs/example.com.crt;
    ssl_certificate_key /etc/ssl/private/example.com.key;

    location / {
        proxy_pass http://nodejs;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection 'upgrade';
        proxy_set_header Host $host;
        proxy_cache_bypass $http_upgrade;
    }

    location /static/ {
        alias /var/www/example.com/static/;
        expires 1y;
        add_header Cache-Control "public, immutable";
    }
}

Nginx Benefits

Performance: Handles 10,000+ concurrent connections with minimal memory. Event-driven architecture scales efficiently. Ideal for high-traffic sites.

Resource Efficiency: ~2.5MB memory per 10K inactive connections. Low CPU usage. Maximizes hardware utilization.

Reverse Proxy Excellence: Best-in-class reverse proxy. Load balancing, health checks, and connection pooling. Essential for microservices.

Modern Protocols: HTTP/2, HTTP/3 (QUIC), gRPC proxy support. WebSocket proxying. TLS 1.3 with modern cipher suites.

Configuration Clarity: Clean, readable configuration syntax. Less cryptic than Apache mod_rewrite. Easier debugging.

Container Native: Small footprint ideal for containers. Official Docker images. Kubernetes ingress controller standard.

No .htaccess: No per-request file parsing overhead. All configuration centralized. Better performance than Apache with AllowOverride enabled.