From my experience (and I have used Sphinx, Lucene, Solr and Xapian in production) is that Lucene/Solr have a pretty bad perfomance compared to Sphinx or Xapian

From my experience (and I have used Sphinx, Lucene, Solr and Xapian in production) is that Lucene/Solr have a pretty bad perfomance compared to Sphinx or Xapian. My Lucene setup began to throw deadlocks and memory exceptions pretty early on. Searching on "deadlock lucene" on Google yields 25000 results. I have later rewritten the system to Xapian where it has run without any problems. For live updates I would recommend using Xapian. For fairly static indexes I would recommend Sphinx (as it's _really_ fast for both indexing and searching, but it does not support live index updates yet).