The document provides an overview of Solr, an open-source enterprise search platform built on the Lucene library, highlighting its features such as hit highlighting, faceted search, and distributed searching. It discusses the indexing process, configuration through schema.xml, and querying functionalities with request handlers. Additionally, the document addresses the implementation of Solr for Assamese and cross-lingual search, as well as future work and conclusions regarding its flexibility and features.

1. Moinuddin Ahmed
-guided by
Dr. Pushpak Bhattacharyya
IIT Bombay
7/15/2012 1

2. Outline
 Solr
 Introduction
 Lucene vs. Solr
 Solr Features
 Indexing in Solr
 Querying in Solr
 Assamese Search Engine
 Monolingual Search
 Cross lingual Search
 Conclusions
 Future Work
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3. What is Solr?
 Solr is an open source enterprise search platform from
the Apache Lucene project.[1]
 Solr=Lucene + added features
 Allows for faster, more comprehensive searches on a
large volume of data
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4. Lucene vs Solr
 Lucene is a library while Solr is a web application that uses
the Lucene library.
 Built on top of Lucene, Solr extends it with a set of robust
features like-
 Hit highlighting
 Index replication
 Faceted searching
 Distributed searching etc..
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5. Features
 Hit Highlighting - Shows a snippet of a document in the search
results that surrounds the search terms.
 Faceted Search – Clusters search results into drill-down
categories. Users can then “categorize" by applying specific
constraints to the search results.
 Distributed Searching: The presence of the shards parameter in a
request will cause that request to be distributed across all shards in the
list.
 Pass a number of optional request parameters to the request handler
to control what information is returned
 External XML Configuration –Solr is flexible and adaptable using
XML configuration
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6. Hit Highlighting example..
snippet
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7. Example of Faceted searching
Manufacturer is
FACET
Dell, HP are
constraints
• is a technique for accessing information organized Facet count
• Faceted search helps users who think in terms of attribute specifications
as filtering criteria.
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8. Faceted searching contd..
 Imagine a situation, where the client wants to have the no. of
companies in the cities where the companies were found by the query.
 One has to return the no. documents with same field value.
 the chosen facet value is used to construct a filter query which
matches that value in the index
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9. Distributed Search
When an index becomes too large to fit on a single system, an index can be
split into multiple shards[2]
A single shard receives the query, distributes the query to other shards
Solr can query and merge results across those shards.
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10. STARTING UP THE SOLR SERVER
 Solr 1.4.1 uses Jetty 6.1.3 server
 Solr is started by the following commnad
java –jar start.jar
 This will start up the jetty application server on
port 8983
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11. INDEXING SOLR
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12. Indexing can be done in two ways:
 Command line :
java -jar post.jar *.xml
 Framework such as Nutch:
bin/nutch solrindex <solr url> <crawldb> -linkdb <linkdb>
(<segment> ... | -dir <segments>)
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13. Schema.xml
 This file contains all of the details about which fields
the documents can contain
 how those fields should be dealt with when adding
documents to the index, or when querying those
fields.
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14. Contents of Schema.xml
1)Data types <type>
2)Fields <field type>
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15. 1)DATA TYPE
<types>
<fieldType name="string" class="solr.StrField” />
<fieldType name="long" class="solr.LongField” />
<fieldType name="float" class="solr.FloatField” />
<fieldType name="text" class="solr.TextField” />
</types>
The <types> section allows one to define:
1. a list of <fieldtype> declarations.
2. underlying Solr class that should be used for that type,
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16. 2)Fields
<field name="id" type="string" indexed="true"
stored="true" multiValued="true"/>
 The <fields> section lists the individual<field> declarations one wishes
to use in documents.
 Each <field> has
 a name that will be used to reference it when adding documents or
executing searches and
 an associated type which identifies the name of the fieldtype one
wishes to use for this field.
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17. Some common options that fields can have are...
 default
 The default value for this field if none is provided while adding
documents
 indexed=true|false
 True if this field should be "indexed". If (and only if) a field is
indexed, then it is searchable, sortable, and facetable.
 stored=true|false
 True if the value of the field should be retrievable during a search
 multiValued=true|false
 True if this field may contain multiple values per document, i.e. if it
can appear multiple times in a document
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18. How to add analyzers in a field?
 <fieldType name="text" class="solr.TextField"
positionIncrementGap="100">
<analyzer type="index">
 <tokenizer class="solr.WhitespaceTokenizerFactory"/>
<filter class="solr.StopFilterFactory"
ignoreCase="true" words="assamese_stop_words.txt"/>
<filter class="solr.AssameseStemFilterFactory"/>
 </analyzer>
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19. Querying SOLR..

20. Adding analyzer during Query time
<fieldType name="text" class="solr.TextField"
positionIncrementGap="100">
<analyzer type=“query">
<tokenizer class="solr.WhitespaceTokenizerFactory"/>
<filter class="solr.StopFilterFactory“
words="assamese_stop_words.txt"/>
<filter class="solr.AssameseStemFilterFactory"/>
<filter class="solr.RemoveDuplicatesTokenFilterFactory"/>
</analyzer>

21. SOLR REQUEST HANDLER
 A SolrRequestHandler is a Solr Plugin that defines the logic
executed for any request.[4]
 Can be implemented either in solrconfig.xml or directly
in the url/user interface.
List of Request Handlers utilized
 StandardRequestHandler
 DisMaxRequestHandler
 LukeRequestHandler
 MoreLikeThisHandler

22. DismaxRequestHandler
 It is designed to process simple user entered phrases and search for the
individual words across several fields using different weighting (boosts)
based on the significance of each field. [4]
 Some parameters of DismaxRequestHandler:
qf(query fields), fl(fields), pf(phrase fields), bq(boost query), etc.
Example
<requesthandler=dismax>
<str name="fl">
title,content,anchor,host,url
</str>
<str name="qf">
url^3.0 anchor content^10.0 title^3.0 host^2.0
</str>
</requesthandler>

23. Response Writers
 A QueryResponseWriter is a Solr Plugin that defines
the response format for any request[3].
 Uses a default format XmlResponseFormat.
 Also has several others response formats like Xslt

24. XSLT RESPONSE WRITER..
 The XSLT Response Writer captures the output of the XML
Response Writer and applies an XSLT transform to it.[3]
 http://localhost:8983/solr/select/?q=‘user query’&wt=xslt&tr=example.xsl
 Parameters:
Wt: writer used
Tr: Selects the XSLT transformation to use, which must be found in
Solr's conf/xslt directory.
 The Content-Type of the response is set according to the <xsl:output>
statement in the XSLT transform, for example:
<xsl:output media-type="text/html"/>

25. IMPLEMENTATION FOR ASSAMESE LANGUAGE

26. FIELDS IN SCHEMA.XML
 HOST
 SITE
 URL
 CONTENT
 TITLE
 LANG
 ID
 TIME
 TOPKWORDS
 DOMAIN
UNIQUE KEY: TIME(in milliseconds)

27. INDEXING
For Assamese monolingual search
Indexed around 500 Assamese text files and about 120URLS
upto depth 3.
For Cross Lingual search
Indexed a few English URL s.

28. Analyzers used…
• Assamese Stemmer
suffix stripping (rule based) + dictionary look-up
accuracy: 80%
• English Porter Stemmer
• Both Assamese and English uses Whitespace tokenizer.
• Stop words are removed in both languages.

29. GUI
Famous temples in Guwahati 29

30. QUERY FORMATION
Famous temples in Guwahati

31. RESULT(XML FORMAT)
Famous temples in Guwahati 31

32. XSLT
Famous temples in Guwahati

33. Future work..
 Parsing the query programmatically.
 Building the resources for adding the Translation and
transliteration modules in the monolingual pipeline.

34. CONCLUSION
 As we now know Solr uses the Lucene search library
and extends it with a set of robust features.
 Solr's powerful external configuration allows it to be
tailored to almost any type of application
 So it is preferable to use Solr is if a programmer wants
to embed its added functionalities into his own
existing application.
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35. REFERENCES
1. Author, Rafal Kuc, Packt Publishing, Apache Solr 1.4.1 Cookbook
2. Author, David Smiley, Eric Pugh, Apache Solr 1.4 Enterprise Edition 2009
3. Apache Lucene, http://lucene.apache.org/solr/ , Feb, 2012
4. Scaling Solr and lucene, http://www.lucidimagination.com/content/scaling-
lucene-and solr#article.highqueryvolume.solr, Feb, 2012
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36. THANK YOU
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37. HELLO
If you guys found this, don’t forget
to give my reference, it a healthy
habit 
• Moinuddin ahmed
7/15/2012 37