How Rackspace Now Uses MapReduce and Hadoop to Query Terabytes of Data | High Scalability

How Rackspace Now Uses MapReduce and Hadoop to Query Terabytes of Data | High Scalability
Nice article on how the Lucene/Hadoop/Solr stack was used to solve a really big problem.  Someday, I hope (when we have actual code),  they can add Mahout to the equation and do even more interesting things with the data.