Nginx FastCGI Cache for OpenCart (micro-caching)

Description

Redis Object Cache reduces database queries. But even with Redis, PHP still executes on every request. Nginx FastCGI Cache goes further: it stores the complete HTML page result and serves it without PHP or MySQL involvement at all. For cached pages TTFB drops to 1–10ms.

We configure Nginx FastCGI Cache for OpenCart and ocStore with correct invalidation logic: session-dependent pages (cart, customer account, admin) are not cached. Cache is cleared automatically when products or prices change.

What We Configure

• fastcgi_cache_path and cache parameters in Nginx configuration
• Cache inclusion rules: cache GET requests for anonymous visitors
• Cache exclusions: /admin, /checkout, /account, /index.php?route=checkout
• Cache bypass for authenticated users (cookie-based)
• Automatic cache invalidation on product updates via OCMOD or script
• X-Cache-Status headers for cache operation diagnostics and control

Performance Impact

On stores with predominantly anonymous traffic (catalogue, search, homepage) FastCGI Cache reduces PHP-FPM and MySQL load by 5–20x. The server handles many more simultaneous visitors without additional hardware resources.