What tips do you have for speeding up (performance of) a MediaWiki installation?

Some great tips here. For me the thing that made the biggest difference (from 8 seconds to 0 on IIS 7) was enabling caching and changing $wgDBserver = "127.0.0.1"; (from localhost). For some reason localhost was being resolved via the network.

Here is the whole post by Jaded:

1. One of the biggest impacts, reducing the load from 15 seconds down to around 6 or 7 was to enable Mediawiki caching and acceleration, as detailed in this post: http://www.charlesrcook.com/archive/2012/09/12/mediawiki-iis7-output-caching-and-friendlyshort-urls.aspx. In short, enable the following in your Mediawiki localsettings.php file:

   $wgCacheDirectory = "c:\your\path\to\cache";
   $wgFileCacheDirectory = "c:\your\path\to\cache ";
   $wgEnableSidebarCache = true;
   $wgUseFileCache = true;
   $wgShowIPinHeader = false;
   $wgEnableParserCache = true;
   $wgCachePages = true;
   
   $wgMainCacheType = CACHE_ACCEL;
   $wgMessageCacheType = CACHE_ACCEL;
   $wgParserCacheType = CACHE_ACCEL;
   $wgMemCachedServers = array();
   

   Make sure your local IUSR and IIS_IUSR accounts have "Modify" permissions on the cache directory, or else the files and directories from Mediawiki caching engine will not be able to write to them.

2. I made some minor changes to caching in PHP using Wincache, but that hardly had any affect - enable and configure it if you wish from a PHP perspective, but don't expect a major jump. The same thing goes for MySQL query caching - my Wiki site is relatively small, with minimum usage, so MySQL query caching wasn't a huge improvement.

3. The final nail in the coffin to bring the site up to speed was modifying the $wgDBserver setting in my Mediawiki LocalSettings.php file. It was set to "Localhost", and this post http://forums.iis.net/t/1153459.aspx/3/10 suggested that using "Localhost" on Windows 7 onwards, and Server 2008 onwards starts getting IPv6 involved in the querying of the page. The transport layer had to resolve localhost and was doing so by negotiating between an IPv4 and an IPv6 address, which PHP and MySQL needed to resolve before allowing the page to render. It appears that this is still not a fully supported integrated protocol, so setting $wgDBserver to the IPv4 address of "127.0.0.1" took the rendering from 6 seconds to just on 1 second - problem solved!

Instead of memory caching especially if your site is small to medium size, so the total size of of all the hmtl pages isn't an issue - a simple solution is to just switch on the file cache instead.

http://www.mediawiki.org/wiki/Manual:File_cache

I spent several hours today trying to switch on any of the mediawiki recommended memory caching solutions on my shared hosting (at bluehost) and found no way to do it, and then discovered this option and it solved all the issues.

This is the wiki with file caching switched on:

http://robertinventor.com/bmwiki

Before file caching it took several seconds to load most pages, and sometimes much longer, up to minutes according to the Google analytics logs.

Switch on caching in LocalSettings.php. Do this by adding / changing this line:

$wgMainCacheType = CACHE_ACCEL;

See Manual:Cache and this mwusers page.

First of all you have to Be sure That You use Apache Server'''. Mediawiki is slower if you have installed on Windows Server Or IIS. If it is on the Windows Server Move the Application Folders to Linux Server. Windows and Linux Server for Mediawiki Guide

This may not be relevant with current versions of MW, but check the php setting mbstring.func_overload. I set it to 2 (as a re-requisite for a small zabbix installation) and it killed the performance of a 1.12 install of MW on the same server.

Use a php opcode cacher, make sure dB is not the bottleneck, consider using a http cacher like varnish.

See these tips: MediaWiki is slow, how can I make it faster?