View source for Manual:Performance tuning/ko

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<span id="Context"></span>
== 요점 ==
<span lang="en" dir="ltr" class="mw-content-ltr">MediaWiki is capable of scaling to meet the needs of large wiki farms such as those of [https://www.wikimedia.org/ Wikimedia Foundation], [https://www.wikihow.com/Main-Page WikiHow] and [https://www.fandom.com/ Fandom] and can take advantage of a wide number of methods including multiple load-balanced database servers, [http://danga.com/memcached memcached] object caching, [https://www.varnish-cache.org/ Varnish caches] (see [[Special:MyLanguage/Manual:Varnish caching|Manual:Varnish caching]]) and multiple application servers.</span>
<span lang="en" dir="ltr" class="mw-content-ltr">For most smaller installations, this is overkill though, and simply enabling object caching and optimizing PHP performance should suffice.</span>

<span id="Quick_start"></span>
== 빠른 시작 ==

<div lang="en" dir="ltr" class="mw-content-ltr">
Short version: We recommend bytecode cache for PHP, APCu as local object cache, Memcached for main cache; this is what the Wikimedia Foundation uses for Wikipedia et al.
</div>

<div lang="en" dir="ltr" class="mw-content-ltr">
In some cases, over-caching at too many levels may degrade performance.
</div>

<span id="Quick_start_with_Puppet"></span>
=== 퍼핏(Puppet)으로 빠르게 시작하기 ===
<span lang="en" dir="ltr" class="mw-content-ltr">Most of the tweaks on this page have been collected in a puppet manifest ({{git file|project=mediawiki/vagrant|file=puppet/modules/role/manifests/simple_performant.pp}} and {{git file|project=mediawiki/vagrant|file=puppet/modules/role/manifests/simple_miser.pp}}).</span>
<span lang="en" dir="ltr" class="mw-content-ltr">If you install [[w:Puppet (software)|Puppet]], you can apply them to your server with a single command.</span>

__TOC__

==PHP==

<span id="Bytecode_caching"></span>
=== 바이트 코드 캐싱 ===
: <span lang="en" dir="ltr" class="mw-content-ltr">See [[Special:MyLanguage/PHP configuration#Opcode caching|PHP configuration#Opcode caching]].</span>

<span lang="en" dir="ltr" class="mw-content-ltr">[[w:PHP|PHP]] works by compiling a PHP file into [https://en.wikipedia.org/wiki/bytecode bytecode] and then executing that bytecode.</span>
<span lang="en" dir="ltr" class="mw-content-ltr">The process of compiling a large application such as MediaWiki takes considerable time.</span>
<span lang="en" dir="ltr" class="mw-content-ltr">[[w:List of PHP accelerators|PHP accelerators]] work by storing the compiled bytecode and executing it directly reducing the time spent compiling code.</span>

<span lang="en" dir="ltr" class="mw-content-ltr">[https://php.net/book.opcache OPcache] is included in PHP 5.5.0 and later and is the recommended accelerator for MediaWiki.</span>
<span lang="en" dir="ltr" class="mw-content-ltr">Other supported op code caches are: WinCache.</span>

<span lang="en" dir="ltr" class="mw-content-ltr">Opcode caches store the compiled output of PHP scripts, greatly reducing the amount of time needed to run a script multiple times.</span>
<span lang="en" dir="ltr" class="mw-content-ltr">MediaWiki does not need to be configured to do PHP bytecode caching and will "just work" once installed and enabled.</span>

<span lang="en" dir="ltr" class="mw-content-ltr">Since MediaWiki 1.36, it may be slower on systems without op code caching.</span>
<span lang="en" dir="ltr" class="mw-content-ltr">See {{task|T274041}}.</span>

{{anchor|Object_caching}}
<span id="Object_caching"></span>
== 객체 캐싱 ==
<span lang="en" dir="ltr" class="mw-content-ltr">For more information about local server, main cache and other cache interfaces, see [[Special:MyLanguage/Manual:Caching|Manual:Caching]].</span>

<span id="Local_server"></span>
=== 웹 서버 ===
<span lang="en" dir="ltr" class="mw-content-ltr">This interface is used for lightweight caching directly on the web server.</span>
<span lang="en" dir="ltr" class="mw-content-ltr">This interface is expected to persist stored values across web requests.</span>

<span lang="en" dir="ltr" class="mw-content-ltr">Presence of a supported backend is automatically detected by MediaWiki.</span>
<span lang="en" dir="ltr" class="mw-content-ltr">No MediaWiki configuration necessary.</span>

<span lang="en" dir="ltr" class="mw-content-ltr">For PHP 7+, you should install [https://php.net/book.apcu APCu] or [https://php.net/intro.wincache WinCache].</span>
(<span lang="en" dir="ltr" class="mw-content-ltr">On PHP 5, APCu was known to be unstable in some cases.</span><ref><span lang="en" dir="ltr" class="mw-content-ltr">APCu GitHub issue 19: [https://github.com/krakjoe/apcu/issues/19 Hung apaches on pthread wrlocks]</span></ref>)

<div lang="en" dir="ltr" class="mw-content-ltr">
To install APCu, use:
</div>

<syntaxhighlight lang="bash">
sudo apt-get install php-apcu php-igbinary
</syntaxhighlight>

<span lang="en" dir="ltr" class="mw-content-ltr">A script, <code>apc.php</code> is bundled with the APCu package which can be used to inspect the status of the cache, and also examine the contents of the user cache to verify that MediaWiki is correctly using it.</span>

<div lang="en" dir="ltr" class="mw-content-ltr">
===Main cache===
</div>

<div lang="en" dir="ltr" class="mw-content-ltr">
This interface is used as the main object cache for larger objects.
</div>

<span lang="en" dir="ltr" class="mw-content-ltr">The main cache is disabled by default and needs to be configured manually.</span>
<span lang="en" dir="ltr" class="mw-content-ltr">To enable it, set {{Wg|MainCacheType}} to a key in {{Wg|ObjectCaches}}.</span>
<span lang="en" dir="ltr" class="mw-content-ltr">There are preconfigured interfaces for Memcached, APC, and MySQL.</span>
<span lang="en" dir="ltr" class="mw-content-ltr">You can configure additional backends via {{phpi|$ObjectCaches}} (e.g. for Redis).</span>

<syntaxhighlight lang="php">
// Default:
// $wgMainCacheType = CACHE_NONE;
</syntaxhighlight>

<div lang="en" dir="ltr" class="mw-content-ltr">
==== Single web server ====
</div>

<span lang="en" dir="ltr" class="mw-content-ltr">If you have APC installed is strongly recommended to use that by setting the following in {{ll|Manual:LocalSettings.php|LocalSettings.php}}:</span>

<syntaxhighlight lang="php">
$wgMainCacheType = CACHE_ACCEL;
</syntaxhighlight>

<div lang="en" dir="ltr" class="mw-content-ltr">
Once set, the user session store and parser output cache will also inherit this MainCacheType setting.
</div>

<span lang="en" dir="ltr" class="mw-content-ltr">When using APC with limited RAM (and no Memcached or other object cache configured), then important objects might be evicted too often due to the size of parser output cache building up.</span>
<span lang="en" dir="ltr" class="mw-content-ltr">Consider setting {{Wg|ParserCacheType}} to CACHE_DB, which will move those keys out to the database instead.</span>

<span lang="en" dir="ltr" class="mw-content-ltr">If using <syntaxhighlight lang=php inline>$wgMainCacheType = CACHE_ACCEL;</syntaxhighlight> and users are unable to login due to "session hijacking" errors, consider overriding {{Wg|SessionCacheType}} to <code>CACHE_DB</code>.</span>
<span lang="en" dir="ltr" class="mw-content-ltr">See task [[phab:T147161|T147161]] for more info.</span>

<span lang="en" dir="ltr" class="mw-content-ltr">If you can't use APC, consider installing {{ll|Manual:Memcached|Memcached}} (requires at least 80MB of RAM).</span>
<span lang="en" dir="ltr" class="mw-content-ltr">While installing Memcached is considerably more complicated, it is very effective.</span>

<div lang="en" dir="ltr" class="mw-content-ltr">
If neither APC or Memcached is an option, you can fallback to storing the object cache in your database.
The following preset will do that:
</div>

<syntaxhighlight lang="php">
$wgMainCacheType = CACHE_DB;
</syntaxhighlight>

<div lang="en" dir="ltr" class="mw-content-ltr">
==== Multiple web servers ====
</div>
<span lang="en" dir="ltr" class="mw-content-ltr">If your MediaWiki site is served by multiple web servers, you should use a central Memcached server.</span>
<span lang="en" dir="ltr" class="mw-content-ltr">Detailed instructions are on the '''{{ll|memcached}}''' page.</span>

<span lang="en" dir="ltr" class="mw-content-ltr">It is important that you '''do not use APC as your main cache''' if you have multiple web servers.</span>
<span lang="en" dir="ltr" class="mw-content-ltr">This cache must be coordinated centrally for a single MediaWiki installation.</span>
<span lang="en" dir="ltr" class="mw-content-ltr">Having each web server use APC as its own MainCache will cause stale values, corruption or other unexpected side-effects.</span>
<span lang="en" dir="ltr" class="mw-content-ltr">Note that for values that are safe to store in uncoordinated fashion (the "local-server cache"), MediaWiki automatically makes use of APC regardless of this configuration setting.</span>

<div lang="en" dir="ltr" class="mw-content-ltr">
=== Interwiki cache ===
</div>
<span lang="en" dir="ltr" class="mw-content-ltr">MediaWiki [[Special:MyLanguage/Help:Interwiki linking|interwiki prefixes]] are stored in the <code>{{ll|Manual:Interwiki table|interwiki}}</code> database table.</span>
<span lang="en" dir="ltr" class="mw-content-ltr">See {{ll|Interwiki cache}} for how to enable caching.</span>

<div lang="en" dir="ltr" class="mw-content-ltr">
=== Localisation cache ===
</div>
<span lang="en" dir="ltr" class="mw-content-ltr">By default, interface message translations are cached in the {{ll|Manual:l10n_cache table|l10n_cache}} database table.</span>
<span lang="en" dir="ltr" class="mw-content-ltr">Ensure {{ll|Manual:$wgCacheDirectory|$wgCacheDirectory}} in {{ll|Manual:LocalSettings.php|LocalSettings.php}} is set to a valid path to use a local caching instead.</span>
<span lang="en" dir="ltr" class="mw-content-ltr">See [[Special:MyLanguage/Help:System message#Caching|Help:System message#Caching]] for more details.</span>

<div lang="en" dir="ltr" class="mw-content-ltr">
=== Sidebar cache ===
</div>
<span lang="en" dir="ltr" class="mw-content-ltr">A small save in DB queries can be obtained by caching the sidebar (disabled by default).</span>
<span lang="en" dir="ltr" class="mw-content-ltr">See <code>{{ll|Manual:$wgEnableSidebarCache|$wgEnableSidebarCache}}</code> and <code>{{ll|Manual:$wgSidebarCacheExpiry|$wgSidebarCacheExpiry}}</code>.</span>

{{anchor|Page view caching}}
<div lang="en" dir="ltr" class="mw-content-ltr">
==Page view caching==
</div>
<span lang="en" dir="ltr" class="mw-content-ltr">Page view caching increases performance tremendously for anonymous (not logged-in) users.</span>
<span lang="en" dir="ltr" class="mw-content-ltr">It does not affect performance for logged-in users.</span>

{{anchor|HTTP caching proxies and HTTP acceleration}}
<div lang="en" dir="ltr" class="mw-content-ltr">
=== Caching proxy ===
</div>
<span lang="en" dir="ltr" class="mw-content-ltr">A caching proxy (or "HTTP accelerator") stores a copy of web pages generated by your web server.</span>
<span lang="en" dir="ltr" class="mw-content-ltr">When such page is requested a second time, then the proxy serves up its local copy, instead of passing the request onto the real web server.</span>

<span lang="en" dir="ltr" class="mw-content-ltr">This massively improves the response times for page loads by end users, and also tremendously reduces the computational load on the MediaWiki web server.</span>
<span lang="en" dir="ltr" class="mw-content-ltr">When a page is edited, MediaWiki can automatically purge the local copy from the cache proxy.</span>

<div lang="en" dir="ltr" class="mw-content-ltr">
Examples of cache proxies:
</div>
* <span lang="en" dir="ltr" class="mw-content-ltr">Varnish Cache, this is currently (as of November 2018) used by Wikipedia.</span> <span lang="en" dir="ltr" class="mw-content-ltr">See also [[Special:MyLanguage/Manual:Varnish caching|Manual:Varnish caching]].</span>
* <span lang="en" dir="ltr" class="mw-content-ltr">[[wikitech:Obsolete:Squids|Squid]], this was used by Wikipedia prior to 2012.</span>
* <span lang="en" dir="ltr" class="mw-content-ltr">[http://httpd.apache.org/docs/current/mod/mod_cache_disk.html Apache's mod_cache_disk], see  [http://timj.testbit.eu/2011/02/09/using-mod_disk_cache-with-mediawiki/ this article] for instructions with MediaWiki.</span>

<div lang="en" dir="ltr" class="mw-content-ltr">
===File cache===
</div>
: <span lang="en" dir="ltr" class="mw-content-ltr">See {{ll|Manual:File cache}} for main article about this.</span>

<span lang="en" dir="ltr" class="mw-content-ltr">In absence of a caching proxy or HTTP accelerator, MediaWiki can optionally use the file system to store the output of rendered pages.</span>
<span lang="en" dir="ltr" class="mw-content-ltr">For larger sites, using an [[#HTTP caching proxies and HTTP acceleration|external cache]] like Varnish is preferable to using the file cache.</span>

<div lang="en" dir="ltr" class="mw-content-ltr">
==Web server==
</div>
* <span lang="en" dir="ltr" class="mw-content-ltr">if you use [[w:Apache HTTP Server|Apache]] as web server, use [[w:PHP-FPM|PHP-FPM]], ''not'' mod_php. PHP-FPM optimizes re-use of PHP processes.</span>
** <span lang="en" dir="ltr" class="mw-content-ltr">switch Apache to use the event MPM instead of the prefork MPM.</span>
* <span lang="en" dir="ltr" class="mw-content-ltr">adjust [[w:Robots.txt|robots.txt]] to disallow bots from crawling history pages.</span> <span lang="en" dir="ltr" class="mw-content-ltr">This decreases general server load.</span> See {{ll|Manual:robots.txt}}.
* <span lang="en" dir="ltr" class="mw-content-ltr">[[w:HTTP/2|HTTP/2]] protocol can help, even with [[Special:MyLanguage/ResourceLoader|ResourceLoader]].</span><ref name=NikePerfFeat><span lang="en" dir="ltr" class="mw-content-ltr">Niklas Laxström, ''[http://laxstrom.name/blag/2013/12/09/performance-is-a-feature/ Performance is a feature]'', December 9th, 2013.</span></ref>

<div lang="en" dir="ltr" class="mw-content-ltr">
==Configuration settings==
</div>
<span lang="en" dir="ltr" class="mw-content-ltr">Large sites running MediaWiki 1.6 or later should set {{ll|Manual:$wgJobRunRate|$wgJobRunRate}} to a low number, say 0.01.</span>
<span lang="en" dir="ltr" class="mw-content-ltr">See {{ll|Manual:Job queue}} for more information.</span>

<div lang="en" dir="ltr" class="mw-content-ltr">
===Composer===
</div>
{{Note|1=<span lang="en" dir="ltr" class="mw-content-ltr">This will provide no benefit if you enable [[#Bytecode caching|opcache]] in PHP.</span>}}

<span lang="en" dir="ltr" class="mw-content-ltr">MediaWiki uses '''composer''' for organizing library dependencies.</span>
<span lang="en" dir="ltr" class="mw-content-ltr">By default these are included from the <code>/vendor</code> directory using a dynamic autoloader.</span>
<span lang="en" dir="ltr" class="mw-content-ltr">This autoloader needs to search directories which can be slow.</span>
<span lang="en" dir="ltr" class="mw-content-ltr">It is recommended to generate a static autoloader with Composer, which will make your wiki respond faster.</span>

<span lang="en" dir="ltr" class="mw-content-ltr">Using a static autoloader is the default for all MediaWiki installations from the tarball download or from Git.</span>
<span lang="en" dir="ltr" class="mw-content-ltr">If for some reason this is not the case, use the following to generate the static autoloader:</span>

<pre>
composer update -o --no-dev
</pre>

<div lang="en" dir="ltr" class="mw-content-ltr">
Remember that this will need to be re-run after each MediaWiki update as it includes a static copy of which libraries and classes exist in the software.
</div>

<div lang="en" dir="ltr" class="mw-content-ltr">
==Database configuration==
</div>

<div lang="en" dir="ltr" class="mw-content-ltr">
===MySQL===
</div>
<span lang="en" dir="ltr" class="mw-content-ltr">For a heavy concurrent write load, InnoDB is essential.</span>
<span lang="en" dir="ltr" class="mw-content-ltr">Use [[Special:MyLanguage/Manual:Memcached|memcached]], not the default MySQL-based object cache.</span>

<span lang="en" dir="ltr" class="mw-content-ltr">See below for some DB configuration tricks.</span>
<span lang="en" dir="ltr" class="mw-content-ltr">You can also try and run the [https://launchpad.net/mysql-tuning-primer mysql-tuning-primer] script to get some quick statistics and suggestions.</span>

<div lang="en" dir="ltr" class="mw-content-ltr">
===Multiple servers===
</div>
<span lang="en" dir="ltr" class="mw-content-ltr">The database software and web server software will start to fight over RAM on busy MediaWiki installations that are hosted on a single server.</span>
<span lang="en" dir="ltr" class="mw-content-ltr">If your wiki has a consistent traffic, a logical step, once other performance optimizations have been made (and cache serves most of the content), is to put the database and web server on separate servers (or, in some cases, multiple separate servers, starting with a replica.)</span>
<span lang="en" dir="ltr" class="mw-content-ltr">Also:</span>

* <span lang="en" dir="ltr" class="mw-content-ltr">check that [[mailarchive:mediawiki-l/2014-February/042544.html|MySQL has query cache enabled and enough memory]];</span>
* <span lang="en" dir="ltr" class="mw-content-ltr">give most [[mailarchive:mediawiki-l/2014-February/042546.html|memory to innodb_buffer_pool]];</span>
* <span lang="en" dir="ltr" class="mw-content-ltr">add cores for MySQL if maxed out at peak times;</span>
* <span lang="en" dir="ltr" class="mw-content-ltr">[[mailarchive:mediawiki-l/2014-February/042542.html|give memcached even more RAM for in-memory cache]].</span>

<div lang="en" dir="ltr" class="mw-content-ltr">
==Benchmarking==
</div>

<div lang="en" dir="ltr" class="mw-content-ltr">
Some tools can help quickly evaluate the effects of performance tuning.
</div>

* <span lang="en" dir="ltr" class="mw-content-ltr">http://webpagetest.org is "real life" testing, commanded in your browser.</span>
* <span lang="en" dir="ltr" class="mw-content-ltr">[https://httpd.apache.org/docs/2.4/programs/ab.html ab] is a command line tool which quickly produces [[gerrit:118815|some nice stats]].</span>
* [https://developers.google.com/speed/pagespeed/ PageSpeed]

<div lang="en" dir="ltr" class="mw-content-ltr">
==See also==
</div>
* http://dammit.lt/2007/01/26/mediawiki-performance-tuning/ : <span lang="en" dir="ltr" class="mw-content-ltr">APC and a few simple settings that boost performance</span>
* <span lang="en" dir="ltr" class="mw-content-ltr">More extensive changes, sacrificing some functionality</span>
** <span lang="en" dir="ltr" class="mw-content-ltr">[[User:Aaron Schulz/How to make MediaWiki fast|How to make MediaWiki fast]]</span>
** <span lang="en" dir="ltr" class="mw-content-ltr">[http://wiki.glitchdata.com/index.php?title=MediaWiki:Performance Comprehensive MediaWiki performance optimisation] (mostly redundant with this page and what above)</span>
* <span lang="en" dir="ltr" class="mw-content-ltr">[[User:Ilmari Karonen/Performance tuning]], focusing on small wikis</span>
* <span lang="en" dir="ltr" class="mw-content-ltr">Use cases:</span>
** <span lang="en" dir="ltr" class="mw-content-ltr">[http://domasmituzas.files.wordpress.com/2011/09/mysqluc2007-wikipedia-workbook.pdf Wikipedia: Site internals, configuration, code examples and management issues] [PDF, 2007]</span>
** <span lang="en" dir="ltr" class="mw-content-ltr">[http://community.livejournal.com/wikifur/70308.html Caching, minification, domain-sharing and compression techniques] used by WikiFur</span>
* <span lang="en" dir="ltr" class="mw-content-ltr">For developers:</span>
** <span lang="en" dir="ltr" class="mw-content-ltr">[[Special:MyLanguage/Manual:How to debug#Logging|Logging]] and {{ll|Manual:Profiling}}</span>
** <span lang="en" dir="ltr" class="mw-content-ltr">[https://github.com/Snugug/north#performance North's Performance chapter]</span>
* <span lang="en" dir="ltr" class="mw-content-ltr">Wikimedia specific documentation:</span>
** <span lang="en" dir="ltr" class="mw-content-ltr">[[wikitech:MediaWiki Engineering/Guides/Backend performance practices|Backend performance guide of the Wikimedia Performance Team]]</span>
** <span lang="en" dir="ltr" class="mw-content-ltr">[[wikitech:MediaWiki Engineering/Guides/Frontend performance practices|Frontend performance guide of the Wikimedia Performance Team]]</span>

<div lang="en" dir="ltr" class="mw-content-ltr">
==References==
</div>
<references/>

[[Category:MediaWiki development{{#translation:}}]]
[[Category:Performance tuning{{#translation:}}]]