-memcached support for MediaWiki:
-
-From ca August 2003, MediaWiki has optional support for memcached, a
-"high-performance, distributed memory object caching system".
-For general information on it, see: http://www.danga.com/memcached/
+MediaWiki has optional support for memcached, a "high-performance,
+distributed memory object caching system". For general information
+on it, see: http://www.danga.com/memcached/
Memcached is likely more trouble than a small site will need, but
for a larger site with heavy load, like Wikipedia, it should help
lighten the load on the database servers by caching data and objects
in memory.
-== Requirements ==
+== Installation ==
+
+Packages are available for Fedora, Debian, Ubuntu and probably other
+Linux distributions. If you there's no package available for your
+distribution, you can compile it from source.
+
+== Compilation ==
* PHP must be compiled with --enable-sockets
memcached servers are not publicly accessible. Otherwise, anyone on
the internet can put data into and read data from your cache.
-An attacker familiar with MediaWiki internals could use this to give
-themselves developer access and delete all data from the wiki's
-database, as well as getting all users' password hashes and e-mail
-addresses.
+An attacker familiar with MediaWiki internals could use this to steal
+passwords and email addresses, or to make themselves a sysop and
+install malicious javascript on the site. There may be other types
+of vulnerability, no audit has been done -- so be safe and keep it
+behind a firewall.
********************* W A R N I N G ! ! ! ! ! ***********************
== Setup ==
-If you want to start small, just run one memcached on your web
-server:
+If you installed memcached using a distro, the daemon should be started
+automatically using /etc/init.d/memcached.
- memcached -d -l 127.0.0.1 -p 11000 -m 64
+To start the daemon manually, use something like:
+
+ memcached -d -l 127.0.0.1 -p 11211 -m 64
(to run in daemon mode, accessible only via loopback interface,
-on port 11000, using up to 64MB of memory)
+on port 11211, using up to 64MB of memory)
In your LocalSettings.php file, set:
$wgMainCacheType = CACHE_MEMCACHED;
- $wgMemCachedServers = array( "127.0.0.1:11000" );
+ $wgMemCachedServers = array( "127.0.0.1:11211" );
The wiki should then use memcached to cache various data. To use
multiple servers (physically separate boxes or multiple caches
usage evenly), make its entry a subarray:
$wgMemCachedServers = array(
- "127.0.0.1:11000", # one gig on this box
- array("192.168.0.1:11000", 2 ) # two gigs on the other box
+ "127.0.0.1:11211", # one gig on this box
+ array("192.168.0.1:11211", 2 ) # two gigs on the other box
);
== PHP client for memcached ==
-As of this writing, MediaWiki includes version 1.0.10 of the PHP
-memcached client by Ryan Gilfether <hotrodder@rocketmail.com>.
-You'll find some documentation for it in the 'php-memcached'
-subdirectory under the present one.
-
-We intend to track updates, but if you want to check for the lastest
-released version, see http://www.danga.com/memcached/apis.bml
+MediaWiki uses a fork of Ryan T. Dean's pure-PHP memcached client.
+The newer PECL module is not yet supported.
-MediaWiki use three object for memcaching:
+MediaWiki uses three object for object caching:
* $wgMemc, controlled by $wgMainCacheType
* $parserMemc, controlled by $wgParserCacheType
* $messageMemc, controlled by $wgMessageCacheType
== Keys used ==
-Ajax Search:
- key: $wgDBname:ajaxsearch:md5( $search )
- ex: wikidb:ajaxsearch:9565814d5d564fa898dd6111b94fae0b
- stores: array with the result of research of a given text
- cleared by: nothing
- expiry: 30 minutes
+(incomplete, out of date)
Date Formatter:
key: $wgDBname:dateformatter
cleared by: Language::loadLocalisation()
Message Cache:
- stored in: $parserMemc
+ stored in: $messageMemc
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
Parser Cache:
stored in: $parserMemc
controlled by: $wgEnableParserCache
- key: $wgDBname:pcache:idhash:$pageid-$renderkey!$hash$edit
+ key: $wgDBname:pcache:idhash:$pageid-$renderkey!$hash
$pageid: id of the page
$renderkey: 1 if action=render, 0 otherwise
- $hash: hash of user options, see User::getPageRenderingHash()
- $edit: '!edit=0' if the user can't edit the page, '' otherwise
+ $hash: hash of user options applied to the page, see ParserOptions::optionsHash()
ex: wikidb:pcache:idhash:1-0!1!0!!en!2
stores: ParserOutput object
- modified by: Article::editUpdates()
- expriy: $wgParserCacheExpireTime or one hour if it contains specific magic
- words
+ modified by: Article::editUpdates() or Article::getOutputFromWikitext()
+ expiry: $wgParserCacheExpireTime or less if it contains short lived functions
+
+ key: $wgDBname:pcache:idoptions:$pageid
+ stores: CacheTime object with an additional list of used options for the hash,
+ serves as ParserCache pointer.
+ modified by: ParserCache::save()
+ expiry: The same as the ParserCache entry it points to.
Ping limiter:
controlled by: $wgRateLimits
Special:Recentchanges (feed):
stored in: $messageMemc
- key: $wgDBname:rcfeed:$format:limit:$imit:minor:$hideminor and
+ key: $wgDBname:rcfeed:$format:$limit:$hideminor:$target and
rcfeed:$format:timestamp
- ex: wikidb:rcfeed:rss:limit:50:minor:0 and rcfeed:rss:timestamp
+ ex: wikidb:rcfeed:rss:50:: and rcfeed:rss:timestamp
stores: xml output of feed
expiry: one day
- clear by: calling Special:Recentchanges?action=purge
+ clear by: maintenance/rebuildrecentchanges.php script, or
+ calling Special:Recentchanges?action=purge&feed=rss,
+ Special:Recentchanges?action=purge&feed=atom,
+ but note need $wgGroupPermissions[...]['purge'] permission.
Statistics:
controlled by: $wgStatsMethod
set in: User::saveToCache()
cleared by: User::saveSettings(), User::clearSharedCache()
-... more to come ...
\ No newline at end of file
+... more to come ...
dépôts / lhc / web / wiklou.git / blobdiff