php缓存和.htaccess缓存

Question

There is another thread similar to this that was closed and that didn't have any useful information in it: https://stackoverflow.com/questions/11955822/php-file-caching-vs-cache-through-htaccess

Is it necessary to implement a php caching system if you are caching through .htaccess? Here is my current .htaccess caching:

<IfModule mod_headers.c>
    # Cache Media Files
    <FilesMatch "\.(ico|pdf|flv|jpg|jpeg|png|gif|swf|mp3|mp4)$">
        Header set Cache-Control "public"
        Header set Expires "Mon, 20 Apr 2015 20:00:00 GMT"
        Header unset Last-Modified
    </FilesMatch>

    # Cache JavaScript & CSS
    <FilesMatch "\.(js|css)$">
        Header set Cache-Control "public"
        Header set Expires "Mon, 20 Apr 2015 20:00:00 GMT"
        Header unset Last-Modified
    </FilesMatch>

    # Disable Caching for Scripts and Other Dynamic Files
    <FilesMatch "\.(pl|php|cgi|spl|scgi|fcgi)$">
        Header unset Cache-Control
    </FilesMatch>
</IfModule>

with this file caching, will building out a php caching system improve my site even more? Or would it make more sense to compress data in .htaccess and use php to cache? I'm just trying to understand which method of caching will improve a site more or if using both is recommended.

Answer 1

You're doing client-side caching for static files only.

Caching in PHP solves a completely different problem - server-side performace issues of your application. So you should use it if your site is loading too slowly or if you're causing high server load.

There are many strategies how to implement server-side caching and it's up to you what fits best your application.

For example you can cache SQL queries results or you can cache HTML output of whole webpages. Do not forget about cache invalidation when your data changes.