I just wanted to say thanks to the Solr developers. I'm now using Solr for the main search engine on Discogs.com. I've been through five revisions of the search engine and this was definitely the least painful. Solr gives me the power of Lucene without having to deal with the guts. It made for a much faster implementation than all other search packages I've worked with.
Some stats: there are now 1.1 million documents in the index and it handles 200,000 searches per day (on a single-cpu P4 server with 1 gig ram). Kevin