Persistent Object Cache
2005 November 14
One of the big recent additions is the Persistent Object Cache. Objects such as pages, categories, options, and users are saved locally to disk so that WP doesn’t have to make a trip to the database. The object cache is completely pluggable, allowing hosts to tailor the cache to their particular usage and needs. Folks on the hackers and testers lists have been shaking out the bugs. The cache is looking pretty stable as of now.
I heard it no longer causes premature hair loss. Looking forward to seeing it in action.
Going to have any speed comparisons for us? I wouldn’t mind hair loss if it is caused by excessive speed, rather than stress.
I get modest improvements of a few percent in my Apache bench benchmarks. I think the persistent cache will be of most use to WPMU. Regardless, the resulting code cleanups from having a clearly defined cache API and the ability to replace the cache implementation wholesale are worthwhile improvements. I’d like to see backends for memcached and other caching deamons so that we can compare numbers.
If I have the cache enabled there are pages of PHP safe mode permission problems – so a few integration issues to be sorted out.
Is there an easy way to clear this cache? I did an upgrade (to some of the latest SVN) and had to turn off the caching because it is storing the db_version as nothing/blank somewhere, so it’s not matching the version in version.php and then WP doesn’t display anything.
Just empty the cache folder, wp-content/cache/ and the cache will recover on its own.
How do you disable caching ? I was going to ask for an option allowing to disable this feature, for testing purpose.
I’ve been hearing of and seeing some problems with mod_rewrite
permalinks and the new object caching code. I haven’t gotten a chance
to look too far into where this might be coming from yet, but its
something to keep your eyes open for.
You’ve said that the object is pluggable, i’m sorry, but where can i find the plugins?
Seems like life is gonna be easier (at least for some people
) )
…. er… hopefully…. in the nearest future. But are you sure that all the OS will be able to make it pluggable?
and it works great with wp-cache too. yay!