Media Wiki CirrusSearch

External

• https://www.mediawiki.org/wiki/Extension:CirrusSearch
• https://www.mediawiki.org/wiki/Help:CirrusSearch

Internal

• Media Wiki Operations
• Elasticsearch

Installation

Install Elasticsearch first. Use the latest version of the recommended major version. At the time of the writing, CirrusSearch for MediaWiki 1.35 recommended Elasticsearch 6.5.4, and 6.8.20 worked fine. Elasticsearch 7.x did not.

Elasticsearch Installation

Install Elastica extension:

Elastica Extension Installation

Download the correct CirrusSearch version from https://www.mediawiki.org/wiki/Special:ExtensionDistributor/CirrusSearch

Unzip it in the extensions directory:

tar -xzf CirrusSearch-REL1_35-95b958b.tar.gz -C /var/www/mediawiki-x.y.z/extensions

Add the following statement to LocalSettings.php:

wfLoadExtension( 'CirrusSearch' );

Smoke test: go to Special:Version and verify that the extension is successfully installed.

Follow the installation instructions delivered with /var/www/mediawiki-1.35.0/extensions/CirrusSearch/README.

In LocalSettings.php:

wfLoadExtension( 'Elastica' );
wfLoadExtension( 'CirrusSearch' );
$wgDisableSearchUpdate = true;

If SELinux is enabled, make sure it is configured to allow the httpd user to connect to elasticsearch, otherwise the setup will fail. See SELinux Setup below.

SELinux Setup

If SELinux is enabled on the host, the httpd process may not be able to invoke into the elasticsearch server, with the following symptoms:

[CirrusSearch] Search backend error during near_match search for 'test' after 5: unknown: Couldn't connect to host, Elasticsearch down?

/var/log/audit/audit.log will contain something similar to:

type=AVC msg=audit(1637546254.160:75): avc:  denied  { name_connect } for  pid=1216 comm="httpd" dest=9200 scontext=system_u:system_r:httpd_t:s0 tcontext=system_u:object_r:wap_wsp_port_t:s0 tclass=tcp_socket permissive=0

Use audit2allow to generate the SELinux policy to allow the denied operation. Follow:

Troubleshooting, Diagnosing and Fixing SELinux Problems

The summary is there:

• Try a search operation that will fail.
• grep httpd /var/log/audit/audit.log | audit2allow -M mysepolicy
• semodule -i mysepolicy.pp

Initialization

As root:

php /var/www/mediawiki-.../extensions/CirrusSearch/maintenance/UpdateSearchIndexConfig.php

Remove

$wgDisableSearchUpdate = true;

from LocalSettings.php.

php /var/www/mediawiki-.../extensions/CirrusSearch/maintenance/maintenance/ForceSearchIndex.php --skipLinks --indexOnSkip
php /var/www/mediawiki-.../extensions/CirrusSearch/maintenance/maintenance/ForceSearchIndex.php --skipParse

In LocalSettings.php:

$wgSearchType = 'CirrusSearch';

Troubleshooting

Enable debugging as shown in:

MediaWiki Troubleshooting

[CirrusSearchRequests] near_match search for 'test' against {index} took 5 millis. Requested via web for 5b7883dcb7cd761f62397caa67819012 by executor 2078481799
[CirrusSearch] Search backend error during near_match search for 'test' after 5: unknown: Couldn't connect to host, Elasticsearch down?

Direct CirrusSearch error logs to a specific file. In LocalSettings.php:

$wgDebugLogGroups['CirrusSearch'] = "/tmp/cirrus-errors.log";

Did not work

Add the following query parameters to dump: &cirrusDumpQuery=true, &cirrusDumpResult=true.