PHP edge caching (LSCache)

Serving PHP through Apache is a proven pattern — .htaccess files, mod_rewrite, mod_php, and decades of hosting infrastructure all rely on it. Ferron can sit in front of this setup as an edge caching proxy, adding high-performance HTTP caching, TLS termination, rate limiting, and DDoS protection without changing your Apache configuration.

Client ──► Ferron (edge cache) ──► Apache (PHP origin) ──► PHP-FPM / mod_php

When paired with an LSCache-compatible PHP plugin (such as LiteSpeed Cache for WordPress, Joomla, or OpenCart), Ferron respects X-LiteSpeed-Cache-Control headers from the PHP application, giving you cache control directly from your app — no server-level tuning required.

Basic edge cache configuration

The simplest setup proxies all requests to Apache on localhost:8080 and enables caching with LSCache override mode:

example.com {
    proxy http://127.0.0.1:8080

    cache {
        max_response_size 2097152
        litespeed_override_cache_control
        emit_litespeed_headers
        vary Accept-Encoding
    }
}

This configuration:

• Proxies every request to Apache, which handles PHP execution via PHP-FPM or mod_php.
• Enables LSCache semantics — X-LiteSpeed-Cache-Control from the PHP app controls cache TTL and scope.
• Emits X-LiteSpeed-Cache response headers (hit/miss/bypass) for debugging and plugin visibility.
• Caches responses separately by Accept-Encoding so compressed and uncompressed variants are stored independently.

WordPress with the LSCache plugin

WordPress sites using the LiteSpeed Cache plugin are the most common deployment of this pattern. The plugin emits X-LiteSpeed-Cache-Control headers on pages it considers cacheable. With litespeed_override_cache_control enabled, Ferron respects those headers and serves cached copies to subsequent visitors, dramatically reducing Apache and PHP-FPM load.

example.com {
    proxy http://127.0.0.1:8080

    cache {
        max_response_size 2097152
        litespeed_override_cache_control
        emit_litespeed_headers
        vary Accept-Encoding
        ignore Set-Cookie
    }
}

The ignore Set-Cookie directive strips Set-Cookie headers from the cached representation while keeping them in the live response — essential for maintaining cacheability alongside session cookies.

Cache exclusion for admin paths

Admin areas, login pages, and checkout flows must never be cached. Use conditional blocks to disable caching for specific paths:

example.com {
    proxy http://127.0.0.1:8080

    cache {
        max_response_size 2097152
        litespeed_override_cache_control
        emit_litespeed_headers
    }

    match EXCLUDE_WORDPRESS_CACHE {
        request.uri.path !~ r"^/(?:wp-(?:admin|login\.php)|wc-api)\b"
    }

    if EXCLUDE_WORDPRESS_CACHE {
        cache false
    }
}

Cache purging from PHP

When content changes — a new blog post, updated product, or comment — the cache must be invalidated. LSCache plugins emit an X-LiteSpeed-Purge response header to invalidate tagged or URL-specific cache entries. Ferron processes these headers automatically when caching is enabled — no additional configuration needed.

Forwarding client IP to Apache

When Ferron terminates client connections, Apache sees all traffic as coming from Ferron’s IP address. Ferron forwards the original client IP automatically so PHP applications and Apache logs see real visitor addresses.

On the Apache side, enable mod_remoteip to trust Ferron’s IP and use X-Forwarded-For for logging and access control:

# Enable in Apache config or an included snippet
RemoteIPHeader X-Forwarded-For
RemoteIPTrustedProxy 127.0.0.1

Replace 127.0.0.1 with Ferron’s actual IP if running on a different host.

Additional edge features

Because Ferron terminates client connections before they reach Apache, you can add edge-level features that apply to all traffic — including cached responses that never touch the backend:

• TLS termination — Offload HTTPS at Ferron with automatic (ACME) or manual certificates. See Automatic TLS and Manual TLS.
• Rate limiting — Protect Apache and PHP from traffic spikes and brute-force attacks. See Rate limiting.
• Abuse protection — Drop malicious requests before they reach the backend. See Abuse protection.
• Security headers — Add headers like Strict-Transport-Security, Content-Security-Policy, and X-Frame-Options at the edge. See Security headers.
• Observability — Log requests, monitor cache hits/misses, and track performance metrics. See Logging & observability.

See also

• HTTP caching — general caching patterns and LSCache overview
• PHP hosting — running PHP directly on Ferron without Apache
• Reverse proxying — proxy configuration reference
• Configuration: HTTP cache — full cache directive reference