Articles & Guides
Useful resources for web developers and system administrators
HTTP
HTTP Cache-Control Headers: Complete Caching Guide
Cache-Control complete guide — max-age, no-store, stale-while-revalidate, public/private, real nginx/Apache setup for static, HTML, API.
HTTP
504 Gateway Timeout Fix: nginx, WordPress, AWS, Cloudflare
504 Gateway Timeout means a proxy gave up waiting for the backend. Find which hop timed out, read nginx logs, fix slow queries, and tune timeouts safely.
HTTP
HTTP 502 Bad Gateway: What It Means and How to Fix
502 Bad Gateway decoded for nginx/Apache + PHP-FPM/Node.js, how it differs from 500/504, 7 causes, step-by-step fixes with config examples.
HTTP
429 Too Many Requests: How Long to Wait and How to Fix It
429 Too Many Requests means you hit a rate limit. Wait for Retry-After or back off exponentially; developers can tune nginx limit_req and send Retry-After.
HTTP
403 Forbidden Error: Fixes for Visitors, nginx, Apache and APIs
403 Forbidden error: find who refused you (Cloudflare, nginx, Apache, WAF, app) from headers and logs, then fix it on Chrome, iPhone, Postman or your server.
HTTP
503 Service Unavailable: Meaning (RFC 9110) and Fixes
503 Service Unavailable (RFC 9110, 15.6.4): the server is overloaded or in maintenance, usually briefly. Retry-After plus nginx, PHP-FPM, IIS fixes.
HTTP
HTTP 301 vs 302 Redirect: Differences and When to Use Each
301 vs 302 redirects compared: SEO impact, when to pick each, and setup examples for nginx, Apache, WordPress, PHP. Avoid common redirect mistakes.
HTTP
500 Internal Server Error: How to Fix It on nginx, Apache, IIS
500 Internal Server Error explained: whose fault it is, whether it fixes itself, real log strings and fixes for nginx, Apache, IIS, WordPress and Cloudflare.
HTTP
How to Fix 404 Not Found Errors: Visitors, nginx, Apache, CDN
Fix a 404 Not Found error: quick checks for visitors, then find which layer answers 404 (CDN, nginx, Apache or the app) with curl and logs, and fix it.
DNS
DNS Records: How to Add, Check and Fix Them — Enterno.io
A practical guide to DNS records: add and edit them in any panel, get TXT right (SPF, DKIM, DMARC), verify with dig, and diagnose failures by symptom.