User:Aaron Schulz/How to make MediaWiki fast

1. Use cache.
2. To LocalSettings.php, add (replace paths as needed):

   # Shared memory settings
   $wgMainCacheType = CACHE_ACCEL;
   $wgMessageCacheType = CACHE_ACCEL;
   $wgCacheDirectory = '<SOME DIRECTORY>';
   $wgUseLocalMessageCache = true;
   $wgParserCacheType = CACHE_DB;
   $wgMemCachedServers = [];
   $wgUseGzip = true;
   $wgEnableSidebarCache = true;
   
   # NO DB HITS!
   $wgDisableCounters = true;
   $wgMiserMode = true;
   
   # Text cache
   $wgCompressRevisions = true; // use with care (see talk page)
   $wgRevisionCacheExpiry = 3*24*3600;
   $wgParserCacheExpireTime = 14*24*3600;
   
   # Diffs (defaults seem ok for Ubuntu and others)
   $wgDiff = 'C:/Server/xampp/htdocs/MW/bin/GnuWin32/bin/diff.exe';
   $wgDiff3 = 'C:/Server/xampp/htdocs/MW/bin/GnuWin32/bin/diff3.exe';
   

3. Set $wgCacheDirectory (above) for use with interface message caching. Make sure that the webserver has permission to make files there.
4. Set up squid servers if possible. Otherwise, at least enable file caching.
5. Set up Memcached if possible. If you do, set $wgMainCacheType and $wgParserCacheType to CACHE_MEMCACHED in LocalSettings.php instead. This is recommended if you have a cluster of servers.
6. Run

   php maintenance/rebuildFileCache.php
   

   if you use file caching (not squids).
7. Set $wgJobRunRate to 0 and set up a crontab or shell script to run jobs (like this with this for example). With $wgJobRunRate at 0 and the above changes, you should be able to avoid db hits on many requests.
8. Set $wgDiff and $wgDiff3 to gnu diff utility (download as needed). This is recommended. The default PHP diff code is slow and crashy.
9. Edit the MediaWiki:Aboutsite and MediaWiki:Pagetitle system messages by changing {{SITENAME}} into your site name. This avoids extra parsing on each hit.
10. If you really need hitcounters, use $wgHitcounterUpdateFreq instead of the $wgDisableCounters setting above.
11. Set up a 404 handler for $wgLocalFileRepo. If not, then at least set $wgShowArchiveThumbnails = false.
12. In the webserver's php.ini file. Make sure realpath_cache_size is set, perhaps to 512k or more.
13. Consider enabling EnableMMAP and EnableSendfile in httpd.conf (for Apache). Please read the Apache docs for NFS and compatibility issues first.
14. [MySQL] Set your mysql server config files to only use server modes corresponding to $wgSQLMode (default is "" for no modes). Restart the mysql server, and then set $wgSQLMode = null.
15. If using SQLite, there are going to be many editors working at a time, and you are willing to sacrifice SERIALIZABLE atomic transactions (key parts of MediaWiki will still use them), you can add this to the bottom of LocalSettings.php:

    $wgDBservers = array(
        array( // master
            'host'        => 'localhost',
            'dbname'    => $wgDBname,
            'user'        => $wgDBuser,
            'password'    => $wgDBpassword,
            'type'        => 'sqlite',
            'load'      => 0,
            'flags'        => 0 // no DBO_TRX (high write concurrency)
        ),
        array( // emulated replica
            'host'        => 'localhost',
            'dbname'    => $wgDBname,
            'user'        => $wgDBuser,
            'password'    => $wgDBpassword,
            'type'        => 'sqlite',
            'load'      => 100,
            'flags'     => DBO_TRX // REPEATABLE-READ for consistency
        )
    );
    

16. If using SQLite, run php maintenance/sql.php and execute PRAGMA journal_mode=WAL;.
17. If using SQLite with the default database job queue, move the job table to another sqlite database.
    1. Open the current database via the sqlite3 command line utility, run .schema job, copy SQL the output, and quit (use ".quit").
    2. Make a new empty <YOUR MEDIAWIKI SQLITE DATA DIRECTORY>/job/<YOUR DB NAME>.sqlite file and open it in sqlite3. Paste in the CREATE TABLE output from above and quit. This should create a new empty job table.
    3. In LocalSettings.php, set:

       $wgJobTypeConf['default']['cluster'] = 'job';
       $wgExternalServers['job'] = [
       	[
       		'type' => 'sqlite',
       		'dbname' => $wgDBname,
       		'dbDirectory' => '<YOUR MEDIAWIKI SQLITE DATA DIRECTORY>/job',
       		'load' => 1
       	]
       ];
       

     Note: Schema updates will have to be manually applied if the main job table changes, as update.php will not see this special database.