[MediaWiki-l] CACHE_ACCEL and "You may want to install APC"

Jeffrey Walton noloader at gmail.com
Fri Dec 21 21:53:02 UTC 2018

Hi Everyone,

I'm in a very unusual state. I had to perform a restore of our html/
directory because I accidentally blew away /var/www/html . We also
lacked a current backup, and our backup was exactly 1 year old. So the
upgrade.php file below is from MW 1.28, IIRC.

I had a current backup of LocalSettings.php from MW 1.30, so I used it
when the restored LocalSettings.php 1.28 caused problems. However, the
1.30 LocalSettings had all the wfLoadExtension and wfLoadSkin
commented because they are not present (yet).

So I have 1.28 Mediawiki, 1.30 LocalSettings, and a missing APC.

Caching and APC is discussed here, but I did not see what needs to be
installed: https://www.mediawiki.org/wiki/Manual:Performance_tuning .

What is APC, and how do I install it?


# yum install apc
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
 * base: centos.mirror.netelligent.ca
 * epel: ewr.edge.kernel.org
 * extras: centos.mirror.netelligent.ca
 * updates: centos.mirror.netelligent.ca
No package apc available.
Error: Nothing to do


# php maintenance/update.php
[f6724eba] [no req]   MWException from line 150 of /var/www/html/w/includes/obje
ctcache/ObjectCache.php: CACHE_ACCEL requested but no suitable object cache is p
resent. You may want to install APC.
#0 /var/www/html/w/includes/objectcache/ObjectCache.php(94): ObjectCache::newAcc
#1 /var/www/html/w/includes/objectcache/ObjectCache.php(74): ObjectCache::newFro
#2 /var/www/html/w/includes/objectcache/ObjectCache.php(46): ObjectCache::newFro
#3 /var/www/html/w/includes/GlobalFunctions.php(3935): ObjectCache::getInstance(
#4 /var/www/html/w/includes/Setup.php(581): wfGetMainCache()
#5 /var/www/html/w/maintenance/doMaintenance.php(97): require_once(string)
#6 /var/www/html/w/maintenance/update.php(216): require_once(string)
#7 {main}

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