Comprehensive Nginx Overview and Configuration Guide

Nginx is an open‑source, high‑performance web and reverse‑proxy server that supports hot deployment, low memory usage, high concurrency, and can run continuously for months without restarting.

Key features include high concurrency, modular architecture, asynchronous event‑driven model, reliability, hot deployment, and a thriving ecosystem.

Typical use cases are serving static files, reverse proxying with caching and load balancing, and providing API services via OpenResty.

Installation on CentOS 7 uses yum install nginx -y, after which you can verify files with rpm -ql nginx and manage the service with systemctl commands such as systemctl start nginx and systemctl status nginx.

Core configuration sections are main, events, and http, with directives like user, worker_processes, worker_connections, and keepalive_timeout controlling process behavior.

Virtual host settings use server_name, root, location, and directives such as return, rewrite, and if to route requests.

Reverse proxy is configured with upstream to define backend servers and proxy_pass to forward traffic, with careful handling of trailing slashes to control URI rewriting.

Load‑balancing strategies include round‑robin (default), least_conn, ip_hash, and hash, allowing distribution of requests across multiple upstream servers.

Caching is enabled with proxy_cache_path, proxy_cache, and related directives to store responses, control validity, and bypass rules, with the $upstream_cache_status variable indicating cache hits.

HTTPS support requires a certificate and key, enabled with listen 443 ssl and related SSL directives.

CORS can be handled by proxying requests through Nginx under the same domain, avoiding browser same‑origin restrictions.

Gzip compression is activated with gzip on, gzip_types, and tuning parameters such as gzip_comp_level and gzip_buffers to reduce payload size.

The Nginx process model consists of a master process and multiple worker processes that share memory, allowing graceful reloads and hot configuration updates without downtime.