Elastica and CirrusSearch extensions
ElasticSearch is a distributed, RESTful search and analytics engine capable of addressing a growing number of use cases. As the heart of the Elastic Stack, it centrally stores your data so you can discover the expected and uncover the unexpected. PHP projects can use the Elastica library to integrate with Elastic Search in an efficient, scalable and well-structured manner.
The Elastica MediaWiki extension is used to integrate MediaWiki with a local ElasticSearch back-end suing the Elastica library and integrating tightly with MediaWiki's object structure. The CirrusSearch extension uses the interface provided by the Elastica extension to provide MediaWiki with an alternative to the default SQL-based search engine. All the Wikimedia projects including Wikipedia use Cirrus Search and Elastica.
Learning the Elastic document structure used by MediaWiki, and the syntax for integrating with it is not well documented, so this page provides some examples of commonly needed processes. This article assumes that all the components are already installed and searching the wiki using the CirrusSearch engine is already working.