MediaWiki extension: Elastica

Provides basic Elasticsearch functionality used by other extensions.

What this provides

First and foremost this provides Elastica, a PHP library used to access Elasticsearch, and the configuration to get it working with MediaWiki's autoloader.

Secondly this provides ElasticsearchConnection, a base type from which extensions can inherit that forms and caches connections in a MediaWiki friendly way. It contains support for indexes that have the concept of "type" and "identifier" in the way that CirrusSearch uses these concepts.

"Type" and "identifier"

Index "type" in the CirrusSearch sense is used to the search corpus into different "types" of index so those indecies can be configured with different sharding and replication configuration, and so suggestions, which are based on term frequency, are more accurate. For example, CirrusSearch has a "content" index type which stores just content articles and a "general" index type which stores all other articles.

Index "identifier" in the CirrusSearch sense is just a string appended to the un-identified name of the index. The full name of the index includes the identifier and that index is aliased to the un-identified name. The applicate refers to the un-identified index (the alias) so that the index can be rebuilt with a different identifier and then the alias can be atomically swapped to the new index.

This extension currently doesn't include support for building or maintaining indices but CirrusSearch's updateOneSearchIndexConfig.php can be used as a model.

Installation

Fetch this plugin plugin into your extensions directory. Make sure you have the curl php library installed (sudo apt-get install php-curl in Debian.) Fetch the elastica library by running "composer install". Add this to LocalSettings.php: wfLoadExtension( 'Elastica' );

Licensing information

CirrusSearch makes use of the Elastica library to connect to Elasticsearch https://elastica.io/. It is Apache licensed and you can read its LICENSE.txt for more information.