Apache Java server
Note this tutorial sets up two seperate solr applications in tomcat, not multi core in one java application.
ApacheSolr for Drupal 6 improves on the out-of-the-box search experience for Drupal users. The easiest way to get Solr running on your Drupal web site is to use the hosted service provided by Acquia; it is way easier than running your own Solr. You simply point your queries to their Solr server and you’re done.
For various reasons, you might want to run your own Solr web service on your own machine. In this article, I will walk you through setting up a working Solr installation using Tomcat 6 on CentOS 6. The end result of this walkthrough will be two separate Solr indexes (via two separate Solr web apps) for two different web sites running on a single Tomcat. I will assume that you are using Acquia’s Drupal (which ships with SolrPHPClient).