Apache Lucene

Lucene

Developer(s)	Apache Software Foundation
Stable release	6.2.0 / August 25, 2016
Development status	Active
Written in	Java
Operating system	Cross-platform
Type	Search and index
License	Apache License 2.0
Website	lucene.apache.org

Apache Lucene is a free and open-source information retrieval software library, originally written in 100% pure Java by Doug Cutting. It is supported by the Apache Software Foundation and is released under the Apache Software License.

Lucene has been ported to other programming languages including Object Pascal, Perl, C#, C++, Python, Ruby and PHP.^[1]

History

Doug Cutting originally wrote Lucene in 1999.^[2] It was initially available for download from its home at the SourceForge web site. It joined the Apache Software Foundation's Jakarta family of open-source Java products in September 2001 and became its own top-level Apache project in February 2005.

Lucene formerly included a number of sub-projects, such as Lucene.NET, Mahout, Tika and Nutch. These three are now independent top-level projects.

In March 2010, the Apache Solr search server joined as a Lucene sub-project, merging the developer communities.

Version 4.0 was released on October 12, 2012.^[3]

The latest version of Lucene is 6.3.0 which was released on November 8, 2016.^[4]

Features and common use

While suitable for any application that requires full text indexing and searching capability, Lucene has been widely recognized^[5][6] for its utility in the implementation of Internet search engines and local, single-site searching.

Lucene has also been used to implement recommendation systems.^[7] For example, Lucene's 'MoreLikeThis' Class can generate recommendations for similar documents. In a comparison of the term vector-based similarity approach of 'MoreLikeThis' with citation-based document similarity measures, such as Co-citation and Co-citation Proximity Analysis Lucene's approach excelled at recommending documents with very similar structural characteristics and more narrow relatedness.^[8] In contrast, citation-based document similarity measures, tended to be more suitable for recommending more broadly related documents,^[8] meaning citation-based approaches may be more suitable for generating serendipitous recommendations, as long as documents to be recommended contain in-text citations.

At the core of Lucene's logical architecture is the idea of a document containing fields of text. This flexibility allows Lucene's API to be independent of the file format. Text from PDFs, HTML, Microsoft Word, Mind Maps, and OpenDocument documents, as well as many others (except images), can all be indexed as long as their textual information can be extracted.^[9]

Lucene-based projects

Lucene itself is just an indexing and search library and does not contain crawling and HTML parsing functionality. However, several projects extend Lucene's capability:

• Apache Nutch — provides web crawling and HTML parsing
• Apache Solr — an enterprise search server^[10]
• Elasticsearch — an enterprise search server^[10][11]
• Compass — the predecessor to Elasticsearch^[12]
• DocFetcher — a multiplatform desktop search application
• Lucene.NET — a port of Lucene written in C# and targeted at .NET Framework users. There are currently two variations of the software, differing in Generics support and a few bug fixes.
• Swiftype - an enterprise search startup based on Lucene^[13]
• Ferret — a search library for Ruby (programming language) inspired by Lucene. There is also a Ruby on Rails plugin called acts_as_ferret.^[14][15] Ferret utilizes Poshlib.
• Kinosearch — a search engine written in Perl and C^[16] and a loose port of Lucene.^[17] The Socialtext wiki software uses this search engine,^[16] and so does the MojoMojo wiki.^[18] It is also used by the Human Metabolome Database (HMDB)^[19] and the Toxin and Toxin-Target Database (T3DB).^[20]
• Apache Lucy is a successor project of both KinoSearch and Ferret, being jointly developed by the authors of these and having bindings in both Perl and Ruby.^[21][22]
• Luke — A Java-based GUI for Lucene which allows you to display and modify indexes.^[23]

Users

For a list of companies that use Lucene (rather than extend), see Lucene's "Powered By" page.^[24] As an example, Twitter is using Lucene for its real time search.^[25]

See also

• Hadoop
• Hibernate search
• Xapian
• Sphinx (search engine)
• List of information retrieval libraries
• LGTE
• Information extraction
• Text mining
• eGranary Digital Library
• Enterprise search
• Manatee (indexing library)

References

1. "LuceneImplementations". apache.org. Retrieved 23 September 2015.
2. KeywordAnalyzer "Better Search with Apache Lucene and Solr" (PDF). 19 November 2007.
3. "Apache Lucene - Welcome to Apache Lucene". apache.org. Retrieved 4 February 2016.
4. "Apache Lucene - Lucene Core News".
5. McCandless, Michael; Hatcher, Erik; Gospodnetić, Otis (2010). Lucene in Action, Second Edition. Manning. p. 8. ISBN 1933988177.
6. GNU/Linux Semantic Storage System
7. J. Beel, S. Langer, and B. Gipp, “The Architecture and Datasets of Docear’s Research Paper Recommender System,” in Proceedings of the 3rd International Workshop on Mining Scientific Publications (WOSP 2014) at the ACM/IEEE Joint Conference on Digital Libraries (JCDL 2014), London, UK, 2014
8. M. Schwarzer, M. Schubotz, N. Meuschke, C. Breitinger, V. Markl, and B. Gipp, https://www.gipp.com/wp-content/papercite-data/pdf/schwarzer2016.pdf "Evaluating Link-based Recommendations for Wikipedia" in Proceedings of the 16th ACM/IEEE-CS Joint Conference on Digital Libraries (JCDL), New York, NY, USA, 2016, pp. 191-200.
9. Perner, Petra (2007). Machine Learning and Data Mining in Pattern Recognition: 5th International Conference. Springer. p. 387. ISBN 978-3-540-73498-7.
10. "What are the main differences between ElasticSearch, Apache Solr and SolrCloud? - Quora". quora.com. Retrieved 23 September 2015.
11. "Elasticsearch: RESTful, Distributed Search & Analytics - Elastic". elastic.co. Retrieved 23 September 2015.
12. "The Future of Compass & Elasticsearch". the dude abides. Retrieved 2015-10-14.
13. Riley, Matt (May 9, 2012). "What is the technology stack behind Swiftype? - Quora". Quora. Retrieved 3 October 2014.
14. https://github.com/jkraemer/ferret Ferret-Github repository
15. http://www.jkraemer.net/projects/acts_as_ferret
16. Natividad, Angela. "Socialtext Updates Search, Goes Kino". CMS Wire. Retrieved 2011-05-31.
17. Marvin Humphrey. "KinoSearch - Search engine library. - metacpan.org". p3rl.org. Retrieved 23 September 2015.
18. Diment, Kieren; Trout, Matt S (2009). "Catalyst Cookbook". The Definitive Guide to Catalyst. Apress. p. 280. ISBN 978-1-4302-2365-8.
19. "HMDB: a knowledgebase for the human metabolome". Nucleic Acids Res. 37 (Database issue): D603–10. January 2009. doi:10.1093/nar/gkn810. PMC 2686599. PMID 18953024.
20. "T3DB: a comprehensively annotated database of common toxins and their targets". Nucleic Acids Res. 38 (Database issue): D781–6. January 2010. doi:10.1093/nar/gkp934. PMC 2808899. PMID 19897546.
21. Michael McCandless; Erik Hatcher; Otis Gospodnetić (2010). Lucene in Action (2 ed.). Manning Publications. p. 338. ISBN 978-1-933988-17-7.
22. "Apache Lucy". apache.org. Retrieved 23 September 2015.
23. "DmitryKey/luke". GitHub. Retrieved 2015-10-14.
24. "PoweredBy". apache.org. Retrieved 23 September 2015.
25. MG Siegler. "Twitter Quietly Launched A New Search Backend Weeks Ago". TechCrunch. AOL. Retrieved 23 September 2015.

Bibliography

• Gospodnetic, Otis; Erik Hatcher; Michael McCandless (28 June 2009). Lucene in Action (2nd ed.). Manning Publications. p. 475. ISBN 1-9339-8817-7.
• Gospodnetic, Otis; Erik Hatcher (1 December 2004). Lucene in Action (1st ed.). Manning Publications. p. 456. ISBN 978-1-9323-9428-3.

External links

• Official website
• Lucene.NET
• List of Lucene Ports (or Implementations) in Other Languages on the Apache wiki
• Schmidt, Marco (2005). "Lucene Wikipedia indexer". Archived from the original on Jul 2006. Introductory article with Java code for search
• Apache Lucene popular APIs in GitHub