[Phpwebsite-developers] Speeding up phpws using file-based caching

[Eloi G. <el...@re...>]

Hi all!

I'd stopped using the phpws cache a couple years ago because of the
extraordinary amount of disk accesses generated.  Even with GLOBAL_CACHE
on, server load was still higher than without the cache.  It was only
recently when I started exploring file-based caching for Article Manager
that I found out why.

What PHPWS_Template::processTemplate does is load the cached completed
template for that particular set of data *AFTER* that data was already
read and prepared by the script!  This is essentially 2 reads on the
same data, which is opposite to what the cache is intended to do.
Furthermore, if a single variable in the data is different, a new INSERT
is sent to the db server.  All this for a small .tpl file that only
wants to be read once and stored in memory for the rest of the
pageview!   I think the solution to this would be to use GLOBAL_CACHE
exclusively for this, and to index only the template name, not a md5
hash of the entire record.

GLOBAL_CACHE should be for items that don't need to be cached past the
pageview, like repetitively-used templates.  As such, it should be a
separate caching call (PHPWS_Cache::set_global) so that these items
don't clutter up the normal caching space.

For all other items, the regular caching calls (PHPWS_Cache::set) should
let you choose between file- or database- based caching.  The reason for
this is that database-based caching is only better if you have premium
hardware acting as a dedicated db server, or if you have one database
backend and multiple webserver frontends.  This is the opposite of the
hardware that 98% of phpws installs are running on.

So what I'd like to do is introduce an option for file-based caching.
Most likely using the PEAR Cache_Lite class
(http://pear.php.net/manual/en/package.caching.cache-lite.intro.php) or
phpCache (http://0x00.org/php/phpCache/).

So, before I start coding, I'd like to hear what you guys think --
good/bad idea?
Any suggestions for a better way to handle caching?
Questions?

-Eloi-