Chad explains how to purge user preferences from cache:
Depends on your caching setup. If you're using
eAccelerator/APC/XCache,
you can clear it by restarting Apache. If you're using the `objectcache` db
table, you can clear it by removing the entries from that table. If you're using
memcache, you can either restart memcache to flush it or use the 'mcc.php'
maintenance script to delete individual entries.
So now I am completely stumped. I have tried clearing all users' 'skin'
preferences (so they will use $wgDefaultSkin) by doing all of the following:
- Delete all rows from the user_properties table where up_property = 'skin'
- truncate table objectcache
- restart Apache (for eAccelerator) and use eAccelerator's own cache-purging command
- Deleted all cache files in $wgCacheDirectory
- User logged out of MediaWiki and logged back in
- User deleted all cookies and browser-cached content
- User restarted web browser
For some users, their skin *still* is not $wgDefaultSkin. It remains monobook, the
previous value of $wgDefaultSkin.
We don't use the other caches you mention.
If they hit Special:Preferences and simply click Save, the problem goes away (for them)
and their skin is now $wgDefaultSkin.
Any other ideas where this skin preference is being cached?
Thanks,
DanB