Apache does caching as well. It's relevant to mod_perl only if you produce proper headers, so your scripts' output can be cached. See the Apache documentation for more details on the configuration of this capability.
To enable caching, use the CacheRoot directive, specifying the directory where cache files are to be saved:
Make sure that directory is writable by the user under which httpd is running.
The CacheSize directive sets the desired space usage in kilobytes:
CacheSize 50000 # 50 MB
Garbage collection, which enforces the cache size, is set in hours by the CacheGcInterval. If unspecified, the cache size will grow until disk space runs out. This setting tells mod_proxy to check that your cache doesn't exceed the maximum size every hour:
CacheMaxExpirespecifies the maximum number of hours for which cached documents will be retained without checking the origin server:
If the origin server for a document did not send an expiry date in the form of an Expires header, then the CacheLastModifiedFactor will be used to estimate one by multiplying the factor by the time the document was last modified, as supplied in the Last-Modified header.
If the content was modified 10 hours ago, mod_proxy will assume an expiration time of 10 × 0.1 = 1 hour. You should set this according to how often your content is updated.
If neither Last-Modified nor Expires is present, the CacheDefaultExpire directive specifies the number of hours until the document is expired from the cache: