Solr is an open source enterprise search platform that uses lucene as indexing and search engine. Solr is written in Java and runs as a standalone search server. Alfresco Community Edition sends HTTP and XML input to Solr and searches for content. Solr updates the cores or indexes and returns the result of the query in XML or JSON format.
In all previous Alfresco Community Edition versions, Solr.war was bundled with the repository. With Alfresco Community Edition 5.2.3, you no longer deploy a Solr.war to your application server. Solr 6 is an independently executable standalone application powered by a Jetty server. Alfresco Community Edition 5.2 uses Solr 4 as the default search service index. For an improved and efficient search functionality, you can upgrade to Alfresco Community Edition with Search Services (Solr 6).
- alfresco: used for searching all live content stored at <SOLR_HOME>/solrhome/alfresco within the Solr search server.
- archive: used for searching content that has been marked as deleted at <SOLR_HOME>/solrhome/archive within the Solr search server.
For more information, see Generating secure keys for Solr communication.