Installing Solr on CentOS/RHEL 6
From the Apache Software Foundation, "Solr is an open source enterprise search server based on the Lucene Java search library, with XML/HTTP and JSON, Ruby, and Python APIs, hit highlighting, faceted search, caching, replication, and a web administration interface." Magento has had built-in support for Solr since Enterprise verion 1.8.
The following instructions show how to complete a basic installation and configuration of Apache Solr for use with Magento Enterprise on CentOS/RHEL 6. These instructions the Java JDK with Tomcat rather than jetty.
Note: Solr should be on a dedicated server if possible, especially for large installations, as it can be resource intensive