GLOSSARY

Apache

Apache (Apache HTTP Server, “httpd”) is a widely used open-source web server that serves and proxies web content, supports modules (e.g., mod_rewrite, mod_ssl, mod_security), and powers millions of sites.

What is Apache?

Apache usually refers to the Apache HTTP Server—an open-source web server from the Apache Software Foundation. It delivers static files, proxies application servers (PHP-FPM, Node.js, Python), terminates TLS, and can be extended via modules.

Disambiguation: “Apache” also names the Apache Software Foundation and other projects (e.g., Kafka, Hadoop, Lucene/Solr). This entry focuses on Apache HTTP Server.

How it works (in brief)

  • Request handling & modules: Core httpd processes requests; modules add features (URL rewriting, TLS, HTTP/2, caching, WAF).
  • Virtual hosts: Multiple domains on one server (name-based vhosts).
  • Reverse proxy: mod_proxy/mod_proxy_http/mod_proxy_fcgi route traffic to backends.
  • Performance: Keep-Alive, MPMs (event/prefork/worker), HTTP/2, gzip/Brotli compression, static asset offload/CDN.

Why it matters for SEO & e-commerce

  • Canonicalization & redirects: Enforce HTTPS, single host, trailing-slash policy; remove redirect chains.
  • Clean URLs: mod_rewrite for human-readable paths that match category/product taxonomy.
  • Indexability controls: Correct status codes, robots.txt, sitemap serving; block bad bot patterns rate-limited or via WAF.
  • Speed & Core Web Vitals: HTTP/2, compression, caching headers, CDN compatibility improve crawl budget and UX.
  • Security signals: HSTS, modern ciphers/TLS; stable availability for crawl consistency.

Best-practice checklist (production storefronts)

  • Canonical host: Force one hostname (e.g., non-www → www) and HTTP→HTTPS with 301.
  • Rewrite hygiene: Prefer one-hop redirects; avoid catch-alls that create loops/soft-404s.
  • Caching & compression: Set Cache-Control for static assets; enable gzip/Brotli; fingerprint assets.
  • Headers: HSTS, CSP (where feasible), correct Content-Type/X-Content-Type-Options.
  • HTTP/2 & MPM event: Use mpm_event with HTTP/2 for concurrency.
  • WAF & bot rules: mod_security (OWASP CRS), rate-limit abusive agents; allow major crawlers.
  • Observability: Access/error logs, request tracing, 4xx/5xx alerting; monitor redirect rates.

Common pitfalls

  • Redirect chains after migrations; mixed content after HTTPS switch.
  • Misordered RewriteCond rules causing infinite loops or accidental noindexing.
  • Serving 200 on error pages (soft-404).
  • Stale TLS/ciphers; missing HSTS; Let’s Encrypt renewal failures.
  • Overly broad bot blocks that accidentally throttle Googlebot/Bingbot.

Examples (e-commerce)

  • Migration: Map legacy /category.php?id=123 → /running-shoes/ with 301, preserve query parameters where needed.
  • SEO hardening: Force HTTPS + canonical host, add HSTS, gzip/Brotli, HTTP/2; unify trailing slash.
  • Proxy pattern: Apache terminates TLS and reverse-proxies to a headless commerce app (Node) and image CDN.

Summary

Apache HTTP Server is a versatile, battle-tested foundation for modern commerce sites. With disciplined rewrite rules, compression, caching, and secure TLS, it enables fast, crawlable, and reliable storefronts—and clean migrations without SEO loss.

FAQ

Is Apache the same as Nginx?

No. Both are web servers/reverse proxies; Apache is module-rich and flexible, Nginx excels at event-driven concurrency. Many stacks use Apache in front of or behind Nginx, or vice versa.

Does Apache configuration affect SEO?

Yes—status codes, redirects, canonical host, compression, caching, and header policies all influence crawlability, speed, and SERP stability.

How do I set a 301 from HTTP to HTTPS in Apache?

Use mod_rewrite in the vhost or .htaccess to redirect ^ <http://> to https:// with a single hop, then test for loops.

Where should robots.txt live?

At https://example.com/robots.txt served by the canonical host, returning 200, small, and cacheable.