Comprehensive Nginx Guide: Introduction, Installation, Core Configuration, and Advanced Practices

Nginx (engine x) is a high‑performance HTTP server and reverse proxy widely used by major Chinese sites such as Baidu, JD.com, and Tencent. It can serve static content, act as a reverse proxy for dynamic back‑ends, and provide load‑balancing and static‑dynamic separation.

1. Nginx Overview

Web Server : Serves static pages and supports CGI languages like Perl and PHP (but not Java, which requires Tomcat). It can handle up to 50,000 concurrent connections.

Reverse Proxy : Clients are unaware of the backend; Nginx forwards requests to backend servers, improving security and scalability.

Load Balancing : Distributes traffic across multiple backend servers, enabling easy scaling and IP address conservation.

Static‑Dynamic Separation : Improves parsing speed by serving static resources from a dedicated server.

2. Installation and Startup

Required packages: pcre-8.37.tar.gz, openssl-1.0.1t.tar.gz, zlib-1.2.8.tar.gz, nginx-1.11.1.tar.gz.

Installation steps (simplified):

# Install PCRE</code>
<code>tar -zxvf pcre-8.37.tar.gz && cd pcre-8.37 && ./configure && make && make install</code>
<code># Install OpenSSL</code>
<code>tar -zxvf openssl-1.0.1t.tar.gz && cd openssl-1.0.1t && ./config && make && make install</code>
<code># Install Zlib</code>
<code>tar -zxvf zlib-1.2.8.tar.gz && cd zlib-1.2.8 && ./configure && make && make install</code>
<code># Install Nginx</code>
<code>tar -zxvf nginx-1.11.1.tar.gz && cd nginx-1.11.1 && ./configure && make && make install

Start Nginx with /usr/local/nginx/sbin/nginx, stop with /usr/local/nginx/sbin/nginx -s stop, and reload with /usr/local/nginx/sbin/nginx -s reload. To enable auto‑start, add the binary path to /etc/rc.d/rc.

3. Core Configuration File (nginx.conf)

The default configuration resides in /usr/local/nginx/conf/nginx.conf and consists of three main sections:

Global block : Sets worker processes, user, PID, and includes.

Events block :

events {</code>
<code>    worker_connections 1024;</code>
<code>}

Controls connection handling and event model.

http block (contains http‑global, server, and location blocks):

http {</code>
<code>    include mime.types;</code>
<code>    default_type application/octet-stream;</code>
<code>    keepalive_timeout 65;</code>
<code>    server {</code>
<code>        listen 80;</code>
<code>        server_name localhost;</code>
<code>        location / {</code>
<code>            root html;</code>
<code>            index index.html index.htm;</code>
<code>        }</code>
<code>    }</code>
<code>}

Handles MIME types, keep‑alive, and virtual hosts.

4. Practical Configurations

Reverse Proxy Example :

server {</code>
<code>    listen 80;</code>
<code>    server_name localhost;</code>
<code>    location / { proxy_pass http://localhost:8001; }</code>
<code>    location ~ /demo1 { proxy_pass http://localhost:8001; }</code>
<code>    location ~ /demo2 { proxy_pass http://localhost:8002; }</code>
<code>}

Load Balancing Example (upstream) :

http {</code>
<code>    upstream myserver {</code>
<code>        ip_hash;</code>
<code>        server localhost:8080 weight=1;</code>
<code>        server localhost:8081 weight=1;</code>
<code>    }</code>
<code>    server {</code>
<code>        listen 80;</code>
<code>        server_name localhost;</code>
<code>        location / { proxy_pass http://myserver; }</code>
<code>    }</code>
<code>}

Load‑balancing strategies include round‑robin (default), weight, ip_hash, and third‑party fair (based on response time).

5. Performance Tuning

Set worker_processes to match CPU cores; each worker handles connections asynchronously. Example:

# Set 4 workers</code>
<code>worker_processes 4;</code>
<code># Bind each worker to a CPU</code>
<code>worker_cpu_affinity 0001 0010 0100 1000;

Adjust worker_connections to control maximum concurrent connections (e.g., worker_connections 1024;). The total possible connections equal worker_processes × worker_connections.

6. High‑Availability Cluster

Combine Keepalived with Nginx for active‑passive or active‑active clusters. Diagrams (omitted) illustrate virtual IP failover and dual‑master setups.

The article concludes with a call for community discussion, QR‑code links for interview questions, and promotional messages.