Sometimes a picture is worth a thousand words. Here's Apache Solr in a multicore setup with two cores, one named hhpn and one named picdinfo. I thought this setup was nice because it allows one site to use the schema from the apachesolr 6.x-1.2 release and one site to use the schema from the 6.x-2.x-dev branch.

References:

http://drupal.org/node/484800
http://janaksingh.com/blog/apachesolr-search-drupal-centos-107

Topic: DrupalApache Solr