Acquia’s Varnish® configuration enforces policies for static files served from
applications on Cloud Platform. In certain circumstances, these configurations
can be modified by changing your website’s .htaccess
file.
Common file types excluded from Varnish caching
The following file types (which are generally large in size) are always excluded from Varnish caching:
dmg
exe
gz
msi
pkg
tgz
zip
You should use a content delivery network (CDN), such as Edge, or another external storage system for serving larger assets of these types.
Files greater than 10 MB in size
HTTP responses with a Content-Length
header larger than 10MB (10,000,000
bytes) in size cannot be cached, but will instead be streamed.
To preserve website uptime and availability, either use a content delivery network (such as Edge) or another external storage system for serving large assets.
Creating custom caching policy per file type
If you want to set a specific cache policy for certain file types, you can add
lines to your .htaccess
file to set a custom Cache-Control
HTTP header
per file type, based on the following example:
# Exclude files of the following types from Varnish caching
<FilesMatch "\.(iso|bmp|psd|flac|avi|mpeg)$">
Header set Cache-Control "max-age=0, private, no-store, no-cache, must-revalidate"
</FilesMatch>