The GlobalUsage extension allows viewing the global usage of images in a wiki farm that uses a shared image repository. It adds Special:GlobalUsage as well as a list of pages that include the image on image description pages.

Install

  • Download and move the extracted GlobalUsage folder to your extensions/ directory.
    Developers and code contributors should install the extension from Git instead, using:
    cd extensions/
git clone https://gerrit.wikimedia.org/r/mediawiki/extensions/GlobalUsage
  • Add the following code at the bottom of your LocalSettings.php file: 
    wfLoadExtension( 'GlobalUsage' );
  • Run the update script which will automatically create the necessary database tables that this extension needs.
  • In LocalSettings, set $wgGlobalUsageDatabase to the identifier of the wiki where the GlobalUsage data is located (usually the database name). It should be the wiki's id as used by the load balancer. (i.e. It should be the database name. If using a table prefix, it should be dbname-prefix). Example: $wgGlobalUsageDatabase = 'commonswiki';
    This name must also be registered to MediaWiki's load balancer: Manual:$wgLBFactoryConf . This configuration structure maps database names to database servers. Note, you must register all databases used in your wikifarm in this structure, even if they are all on the same database server, for this extension to work.
  • You must use either the $wgConf site configuration system or the db Manual:Sites table for GlobalUsage to be able to link to your other wikis. You don't neccesarily have to use it for all your wiki configuration, but it is important to use it for $wgServer and $wgArticlePath.
  • Run refreshGlobalimagelinks.php on all wikis in your farm. This will take a long time, but only needs to be done once when installing the extension: php extensions/GlobalUsage/maintenance/refreshGlobalimagelinks.php --pages=existing,nonexisting
  • Yes Done – Navigate to Special:Version on your wiki to verify that the extension is successfully installed.

Specific guide on how to link file usage by sites table

  1. Make sure that $wgGlobalUsageDatabase and $wgLBFactoryConf were set properly.
  2. Use maintenance script importSites.php to build an XML format site list file. (Instruction can be found here: sitelist.txt, sample file can be found here: sitelist-1.0.xsd.)
  3. Use $wgSharedDB = 'commonswiki'; and $wgSharedTables[] = 'sites'; to share sites table across all wikis.
  4. Clean all cache and force refresh like by refreshGlobalimagelinks.php.

As of GlobalUsage version 2.2.0, $wgGlobalUsageDatabase is no longer used. The extension now uses MediaWiki's virtual domain system. The correct configuration variable is $wgVirtualDomainsMapping.

On each content wiki (wikis that use files from the shared repo)

// Must be set BEFORE wfLoadExtension
$wgVirtualDomainsMapping['virtual-globalusage'] = [ 'db' => 'my_media_wiki_db' ];
$wgGlobalUsageSharedRepoWiki = 'my_media_wiki_db';

wfLoadExtension( 'GlobalUsage' );

Replace my_media_wiki_db with the $wgDBname of your shared media/file repository wiki. 

// Must be set BEFORE wfLoadExtension
$wgVirtualDomainsMapping['virtual-globalusage'] = [ 'db' => 'my_media_wiki_db' ];
$wgGlobalUsageSharedRepoWiki = 'my_media_wiki_db';

wfLoadExtension( 'GlobalUsage' );

// Required for WikiMap to resolve wiki IDs to display names and URLs.
// Without this, file pages will show raw database names instead of
// wiki names, and links to pages on other wikis will not work.
$wgLocalDatabases = [ 'my_wiki_1_db', 'my_wiki_2_db', 'my_media_wiki_db' ];

$wgConf->wikis    = [ 'my_wiki_1_db', 'my_wiki_2_db', 'my_media_wiki_db' ];
$wgConf->suffixes = [ 'mysuffix' ]; // A common suffix shared by your DB names, or any string

$wgConf->siteParamsCallback = static function ( $conf, $wiki ) {
    return [
        'suffix' => 'mysuffix',
        'lang'   => 'en',
        'params' => [],
        'tags'   => [],
    ];
};

$wgConf->settings = [
    'wgServer' => [
        'my_wiki_1_db'    => 'https://wiki1.example.org',
        'my_wiki_2_db'    => 'https://wiki2.example.org',
        'my_media_wiki_db' => 'https://media.example.org',
    ],
    'wgArticlePath' => [
        'default' => '/wiki/$1',
    ],
    'wgSitename' => [
        'my_wiki_1_db'    => 'My Wiki',
        'my_wiki_2_db'    => 'My Wiki (DE)',
        'my_media_wiki_db' => 'My Media Wiki',
    ],
];

Cross-database access

The DB user for each content wiki must have SELECT, INSERT, UPDATE, and DELETE privileges on the media wiki's database. If your wikis use separate database users, grant access as a MySQL/MariaDB root user: 

GRANT SELECT, INSERT, UPDATE, DELETE ON my_media_wiki_db.* TO 'wiki1_user'@'localhost';
GRANT SELECT, INSERT, UPDATE, DELETE ON my_media_wiki_db.* TO 'wiki2_user'@'localhost';
FLUSH PRIVILEGES;

Running update.php

After configuring $wgVirtualDomainsMapping, run update.php on each wiki. GlobalUsage uses addExtensionUpdateOnVirtualDomain, which creates the globalimagelinks table in the correct database (the media wiki's DB).

If globalimagelinks was accidentally created in the wrong database (e.g. before $wgVirtualDomainsMapping was set), drop it and re-run update.php: 

DROP TABLE globalimagelinks;

Backfilling with refreshGlobalimagelinks.php

Run the refresh script from each content wiki only — not from the media wiki. The script uses the executing wiki's $wgDBname to stamp the gil_wiki field, and writes to the media wiki's database via the virtual domain mapping. 

php extensions/GlobalUsage/maintenance/refreshGlobalimagelinks.php

Do NOT run on the repository/commons wiki. Running this script from the media wiki itself will result in all rows being stamped with the media wiki's own DB name, and no cross-wiki usage will appear.

Notes

  • $wgGlobalUsageDatabase is silently ignored in v2.2.0+. If you are upgrading from an older version, replace it with $wgVirtualDomainsMapping as shown above.
  • $wgVirtualDomainsMapping must be set before wfLoadExtension( 'GlobalUsage' ).
  • $wgConf settings on the media wiki are required for links to work. Without them, file pages display raw database names (e.g. mywiki_db) with no hyperlink.
  • The virtual domain name used by this extension is virtual-globalusage (hardcoded in extension.json).

API

Extension:GlobalUsage includes an API extension that allows bots and other programs to query the global usage of a file. For example, this query on Wikimedia Commons returns global uses of File:Example.jpg:

Result
<?xml version="1.0"?>
<api>
  <query>
    <pages>
      <page pageid="6428847" ns="6" title="File:Example.jpg">
        <globalusage>
          <gu title="Ашаблон:Ацқьа" wiki="ab.wikipedia.org" url="http://ab.wikipedia.org/wiki/%D0%90%D1%88%D0%B0%D0%B1%D0%BB%D0%BE%D0%BD:%D0%90%D1%86%D2%9B%D1%8C%D0%B0" />
          <gu title="Wikipedia_ውይይት:Can&#039;t_see_the_font?" wiki="am.wikipedia.org" url="http://am.wikipedia.org/wiki/Wikipedia_%E1%8B%8D%E1%8B%AD%E1%8B%AD%E1%89%B5:Can%27t_see_the_font%3F" />
          <gu title="አባል:Blockinblox" wiki="am.wikipedia.org" url="http://am.wikipedia.org/wiki/%E1%8A%A0%E1%89%A3%E1%88%8D:Blockinblox" />
          <gu title="አባል_ውይይት:Hana.oww" wiki="am.wikipedia.org" url="http://am.wikipedia.org/wiki/%E1%8A%A0%E1%89%A3%E1%88%8D_%E1%8B%8D%E1%8B%AD%E1%8B%AD%E1%89%B5:Hana.oww" />
          <gu title="አባል:Beza" wiki="am.wikipedia.org" url="http://am.wikipedia.org/wiki/%E1%8A%A0%E1%89%A3%E1%88%8D:Beza" />
          <gu title="መደብ:ኪነት" wiki="am.wikipedia.org" url="http://am.wikipedia.org/wiki/%E1%88%98%E1%8B%B0%E1%89%A5:%E1%8A%AA%E1%8A%90%E1%89%B5" />
          <gu title="መደብ_ውይይት:ተረትና_ምሳሌ" wiki="am.wikipedia.org" url="http://am.wikipedia.org/wiki/%E1%88%98%E1%8B%B0%E1%89%A5_%E1%8B%8D%E1%8B%AD%E1%8B%AD%E1%89%B5:%E1%89%B0%E1%88%A8%E1%89%B5%E1%8A%93_%E1%88%9D%E1%88%B3%E1%88%8C" />
          <gu title="ስዕል:መርጡለ_ማርያም_ገዳም_.jpg" wiki="am.wikipedia.org" url="http://am.wikipedia.org/wiki/%E1%88%B5%E1%8B%95%E1%88%8D:%E1%88%98%E1%88%AD%E1%8C%A1%E1%88%88_%E1%88%9B%E1%88%AD%E1%8B%AB%E1%88%9D_%E1%8C%88%E1%8B%B3%E1%88%9D_.jpg" />
          <gu title="User_talk:Rasheduzzaman_Raj" wiki="ang.wikipedia.org" url="http://ang.wikipedia.org/wiki/User_talk:Rasheduzzaman_Raj" />
          <gu title="User:Danceteamcherleaders" wiki="ang.wikipedia.org" url="http://ang.wikipedia.org/wiki/User:Danceteamcherleaders" />
        </globalusage>
      </page>
    </pages>
  </query>
  <query-continue>
    <globalusage gucontinue="Example.jpg|arwiki|77967" />
  </query-continue>
</api>

By default, this returns only 10 results. The next 10 results can be retrieved using the gucontinue= parameter included in the result above:

The number of results returned is set with the gulimit parameter. The guprop parameter sets which properties to retrieve. The gufilterlocal parameter, when set to 1, will exclude uses on the same wiki as the file (e.g., on Commons). The following query retrieves all properties and up to 100 results, excluding local uses:

This extension is being used on one or more Wikimedia projects. This probably means that the extension is stable and works well enough to be used by such high-traffic websites. Look for this extension's name in Wikimedia's CommonSettings.php and InitialiseSettings.php configuration files to see where it's installed. A full list of the extensions installed on a particular wiki can be seen on the wiki's Special:Version page.
This extension is included in the following wiki farms/hosts and/or packages: