Nginx Overview

Nginx is a high-performance HTTP server and reverse proxy known for low memory usage and strong concurrency support. It serves static content efficiently and handles dynamic content via CGI protocols like Perl and PHP, but requires Tomcat for Java applications. Optimized for high-load environments, Nginx supports up to 50,000 concurrent connections.

Key Advantages

• Cross-platform compatibility: Runs on Unix/Linux and Windows
• High-performance web and reverse proxy capabilities
• Exceptional concurrency handling

Rationale for Nginx

Single Tomcat instances typically handle 150-200 concurrent users. Scaling to nationla-level services requires distributing load across multiple servers. Nginx provides software-based load balancing at near-zero cost, widely adopted by major e-commerce platforms.

Proxy Concepts

Forward Proxy Acts as intermediary for clients accessing external resources. Benefits include:

1. Accessing otherwise restricted resources
2. Caching for acccelerated access
3. Anonymizing client identity

Reverse Proxy Clients interact with proxy unaware of backend servers. Benefits include:

1. Hiding server infrastructure
2. Distributing client requests
3. Providing unified access point

Load Balancing Fundamentals

Vertical scaling (hardware upgrades) becomes impractical at scale. Horizontal scaling via server clusters distributes requests across multiple nodes:

flowchart LR
    Client --> ReverseProxy
    ReverseProxy --> Server1
    ReverseProxy --> Server2
    ReverseProxy --> ServerN

Installation Methods

Windows Installation

Download executable from nginx.org and run nginx.exe

Linux Installation

Prerequisites

yum install gcc-c++ pcre pcre-devel zlib zlib-devel openssl openssl-devel

Procedure

mkdir /usr/local/nginx
cd /usr/local/nginx
wget http://nginx.org/download/nginx-1.24.0.tar.gz
tar -xvf nginx-1.24.0.tar.gz
cd nginx-1.24.0
./configure
make
make install

Service Management

# Start
/usr/local/nginx/sbin/nginx

# Graceful shutdown
/usr/local/nginx/sbin/nginx -s quit

# Immediate stop
/usr/local/nginx/sbin/nginx -s stop

# Reload configuration
/usr/local/nginx/sbin/nginx -s reload

Docker Deployment

docker pull nginx

mkdir -p /home/nginx/{www,conf,log}

docker run -p 80:80 --name nginx --restart always \
  -v /home/nginx/www:/usr/share/nginx/html \
  -v /home/nginx/conf/nginx.conf:/etc/nginx/nginx.conf \
  -v /home/nginx/log:/var/log/nginx -d nginx

Configuration Guide

Virtual Host Setup

Modify /usr/local/nginx/conf/nginx.conf for:

• IP-based hosting
• Domain-based hosting
• Port configuration

Reverse Proxy Implementation

Route www.localhost.com:80 to 127.0.0.1:8080:

http {
    upstream backend {
        server localhost:8080;
    }

    server {
        listen 80;
        server_name localhost;

        location / {
            proxy_pass http://backend;
        }
    }
}

Load Balancing Methods

Round Robin (Default)

upstream app_servers {
    server localhost:8080;
    server localhost:9999;
}

server {
    location / {
        proxy_pass http://app_servers;
    }
}

Weighted Distribution

upstream app_servers {
    server localhost:8080 weight=5;
    server localhost:9999 weight=1;
}

IP Hash Session Persistence

upstream app_servers {
    ip_hash;
    server localhost:8080;
    server localhost:9999;
}

Least Connections

upstream app_servers {
    least_conn;
    server localhost:8080;
    server localhost:9999;
}