Twitter Search is Now Based on Lucene
Twitter to contribute Twitter.com changes back to Lucene.
Team Twitter have revealed that they launched a new backend for search on Twitter.com over the last few weeks. The new search backend is based on the Lucene search engine library.
Twitter have rewritten parts of Lucene’s core in-memory data structures – with a particular focus on the posting lists – and introduced lock-free data structures and algorithms. They have also worked on the garbage collection performance. Twitter plan to contribute these changes back to Lucene. Despite the changes, support for Lucene’s standard APIs has been retained.