Apache Solr (http://lucene.apache.org/solr) is a powerful search engine built on Apache Lucene. In fact, Apache Solr is a standalone enterprise search server with a REST API. The main advantage of this solution is that it can be easily installed as a cloud. Apache Solr has many other advantages, such as high traffic volume optimization, administration interfaces, easy monitoring, high scalability and fault tolerance, and more. Refer to the official site at http://lucene.apache.org/solr/features.html to read about these features.

Apache Solr supports both a schema mode as well as a schema-free one. The schema is a place where you build an index and define fields that consist of it. The schema-free mode allows users to rapidly construct an effective schema by simply indexing sample data, without having to manually edit the schema. The Liferay plugin called solr4-web provides schema and Solr configuration. Thus, we will use this configuration to run Solr in...