A little ominous, but I’ve not noticed any difference in performance thus far. I’m seeing the following in my log frequently:
Info cli Memcache \OC\Memcache\APCu not available for distributed cache 2016-08-31T13:15:01+00:00 --
Info cli Memcache \OC\Memcache\APCu not available for local cache 2016-08-31T13:15:01+00:00 --
If you don’t specify a distrubuted cache we use the same as the localcache. This is where the double warning comes from. This is done so we have fewer code paths.
Restarted apache, and now APCu is showing as enabled.
This likely needs documenting in the NC docs, along with recommended defaults for the above settings (and other settings if required, I think I’ve got the minimum listed there).
Logs are now clean of APCu errors, so that was that.
It’d be interesting to know why installing and enabled APCu on PHP7 didn’t pre-populate the required fields as I presume it does in PHP5 (otherwise there’d be countless threads on this, right?).
There you need to ask the distribution which ships the packages for you. In most cases, manually added php-modules are enabled. PHP7 is quite new, and I’m not sure if all the caching solutions were available from the beginning (in a stable version). But that’s just a guess.
An ls -l /path/to/user/cache shows 0, but ls -la indicates there are over 500 records for my main user account. I think it’s doing something, though maybe @rullzer or @tflidd can shine some more light on the subject.
the folder /path/to/nextcloud/data/user/cache is mainly used for uploads (client uploads chunks of files which are then assembled once all of them are received). Not sure if there is also other stuff. But in most cases the folder should be pretty empty unless you are uploading something.
APCU/redis manage their cache at a different location. Check the redis/apcu documentation if you are interested in more details (e.g. runtime information).