Introduction to Open Source Search with Apache Lucene and Solr Grant Ingersoll The How Many Game •How many of you: o Have taken a class in Information Retrieval (IR)? o Are doing work/research in IR? o Have heard of or are using Lucene? o Have heard of or are using Solr? o Are doing work on core IR algorithms such as compression techniques or scoring? o Are doing UI/Application work/research as they relate to search? Lucid Imagination, Inc. Topics •Brief Bio •Search 101 (skip?) •What is: o Apache Lucene o Apache Solr •What can they do? o Features and functionality o Intangibles •What’s new in Lucene and Solr? o How can they help my research/work/____? Lucid Imagination, Inc. Brief Bio •Apache Lucene/Solr Committer •Apache Mahout co-founder o Scalable Machine Learning •Co-founder of Lucid Imagination o http://www.lucidimagination.com •Previously worked at Center for Natural Lang. Processing at Syracuse Univ. with Dr. Liddy •Co-Author of upcoming “Taming Text” (Manning Publications) o http://www.manning.com/ingersoll Lucid Imagination, Inc. Search 101 •Search tools are designed for dealing with fuzzy data/questions o Works well with structured and unstructured data o Performs well when dealing with large volumes of data o Many apps don’t need the limits that databases place on content o Search fits well alongside a DB too • Given a user’s information need, (query) find and, optionally, score content relevant to that need o Many different ways to solve this problem, each with tradeoffs •What’s “relevant” mean? Lucid Imagination, Inc. Search 101 Relevance Indexing Vector Space Model (VSM) for relevance Finds and maps terms and documents Common across many search engines Apache Lucene is a highly optimized implementation of the VSM Conceptually similar to a book index At the heart of fast search/retrieve Apache Lucene in a Nutshell •http://lucene.apache.org/java •Java based Application Programming Interface (API) for adding search and indexing functionality to applications •Fast and efficient scoring and indexing algorithms •Lots of contributions to make common tasks easier: o Highlighting, spatial, Query Parsers, Benchmarking tools, etc. •Most widely deployed search library on the planet Lucid Imagination, Inc. Lucene Basics •Content is modeled via Documents and Fields o Content can be text, integers, floats, dates, custom o Analysis can be employed to alter content before indexing •Searches are supported through a wide range of Query options o Keyword o Terms o Phrases o Wildcards o Many, many more Lucid Imagination, Inc. Apache Solr in a Nutshell •http://lucene.apache.org/solr •Lucene-based Search Server + other features and functionality •Access Lucene over HTTP: o Java, XML, Ruby, Python, .NET, JSON, PHP, etc. •Most programming tasks in Lucene are configuration tasks in Solr •Faceting (guided navigation, filters, etc.) •Replication and distributed search support •Lucene Best Practices Lucid Imagination, Inc. A small sampling of Lucene/Solr-Powered Sites Buy.com 10 Features and Functionality Lucid Imagination, Inc. Quick Solr/Lucene Demo •Pre-reqs: o Apache Ant 1.7.x, Subversion (SVN) •Command Line 1: o svn co https://svn.apache.org/repos/asf/lucene/dev/trunk solr-trunk o cd solr-trunk/solr/ o ant example o cd example o java –Dsolr.clustering.enabled=true –jar start.jar •Command Line 2 o cd exampledocs; java –jar post.jar *.xml •http://localhost:8983/solr/browse?q=&debugQuery=true&annotate Browse=true Lucid Imagination, Inc. Other Features •Data Import Handler o Database, Mail, RSS, etc. •Rich document support via Apache Tika o PDF, MS Office, Images, etc. •Replication for high query volume •Distributed search for large indexes o Production systems with 1B+ documents •Configurable Analysis chain and other extension points o Total control over tokenization, stemming, etc. Lucid Imagination, Inc. Intangibles •Open Source •Flexible, non-restrictive license o Apache License v2 – non-viral o “Do what you want with the software, just don’t claim you wrote it” •Large community willing to help o Great place to learn about real world IR systems •Many books and other documentation o Lucene in Action by Hatcher, McCandless and Gospodnetic Lucid Imagination, Inc. What’s New? •https://svn.apache.org/repos/asf/lucene/dev/trunk/lucene/C HANGES.txt •https://svn.apache.org/repos/asf/lucene/dev/trunk/solr/CHA NGES.txt •Codecs o Pluggable Index Formats o Provide Different index compression techniques •Stats to enable alternate scoring approaches BM25, Lang. Modeling, etc. -- More work to be done here •Faster o Java Strings are slow; convert to use byte arrays Lucid Imagination, Inc. Other New Items •Many new Analyzers (tokenizers, etc.) o Richer Language support (Hindi, Indonesian, Arabic, …) •Richer Geospatial (Local) Search capabilities o Score, filter, sort by distance o http://wiki.apache.org/solr/SpatialSearch •Results Grouping o Group Related Results o http://wiki.apache.org/solr/FieldCollapsing •More Faceting Capabilities o Pivot o New underlying algorithms Lucid Imagination, Inc. How can Lucene/Solr help me? Everyone User Experience Researchers • Fast indexing/search times means less time waiting for jobs to complete • Completely Open (source, community) • Free to use, modify, etc. • Large community ready and willing to help • Rapid UI prototyping • Total Control of results and facets • Easy to setup and use with little to no programming required Lucene/Solr IR Researchers Job Seekers • Flexible Indexing models (trunk) • Flexible Relevance models via functions and other mechanisms • Extendable • Google Summer of Code • Other Internships (see me) • Real programming skills that are highly valued in industry • Publicly visible, demonstrable skills Lucid Imagination, Inc. Job Trends http://www.indeed.com Lucid Imagination, Inc. Other Things that Can Help • Nutch o Crawling o http://nutch.apache.org • Mahout o Machine learning (clustering, classification, others) o http://mahout.apache.org • OpenNLP o Part of Speech, Parsers, Named Entity Recognition o http://incubator.apache.org/opennlp • Open Relevance Project o Relevance Judgments o http://lucene.apache.org/openrelevance Lucid Imagination, Inc. Resources •http://lucene.apache.org •http://www.lucidimagination.com [email protected] [email protected] •http://www.slideshare.net/gsingers [email protected] Lucid Imagination, Inc.