MediaWiki uses a fork of Ryan T. Dean's pure-PHP memcached client.
It also supports the PECL PHP extension for memcached.
-MediaWiki uses three object for object caching:
-* $wgMemc, controlled by $wgMainCacheType
-* $parserMemc, controlled by $wgParserCacheType
-* $messageMemc, controlled by $wgMessageCacheType
-If you set CACHE_NONE to one of the three control variable, (default
-value for $wgMainCacheType), MediaWiki still create a MemCacheClient,
-but requests to it are no-ops and we always fall through to the
-database. If the cache daemon can't be contacted, it should also
-disable itself fairly smoothly.
-
-By default, $wgMemc is used but when it is $parserMemc or $messageMemc
-this is mentioned below.
+MediaWiki uses the ObjectCache class to retrieve instances of
+BagOStuff by purpose, controlled by the following variables:
+* $wgMainCacheType
+* $wgParserCacheType
+* $wgMessageCacheType
+
+If you set one of these to CACHE_NONE, MediaWiki still creates a
+BagOStuff object, but calls it to it are no-ops. If the cache daemon
+can't be contacted, it should also disable itself fairly smoothly.
== Keys used ==
cleared by: Language::loadLocalisation()
Message Cache:
- stored in: $messageMemc
+ backend: $wgMessageCacheType
key: $wgDBname:messages, $wgDBname:messages-hash, $wgDBname:messages-status
ex: wikidb:messages, wikidb:messages-hash, wikidb:messages-status
stores: an array where the keys are DB keys and the values are messages
expiry: 30 minutes
Parser Cache:
- stored in: $parserMemc
+ access: ParserCache
+ backend: $wgParserCacheType
key: $wgDBname:pcache:idhash:$pageid-$renderkey!$hash
$pageid: id of the page
$renderkey: 1 if action=render, 0 otherwise
cleared by: session_destroy()
Sidebar:
- stored in: $parserMemc
+ access: WANObjectCache
controlled by: $wgEnableSidebarCache
key: $wgDBname:sidebar
ex: wikidb:sidebar
cleared by: nothing
Special:Recentchanges (feed):
- stored in: $messageMemc
+ backend: $wgMessageCacheType
key: $wgDBname:rcfeed:$format:$limit:$hideminor:$target and
rcfeed:$format:timestamp
ex: wikidb:rcfeed:rss:50:: and rcfeed:rss:timestamp