The document provides an overview of Lucene and Solr, emphasizing their flexibility, speed, and ability to handle various data types including geospatial data and near real-time indexing. It highlights new features in Solr 4.x, such as enhanced relevance functions, new admin UI, and improved search capabilities, while discussing potential applications for search technology in diverse fields. The document also covers community engagement, testing practices, and the evolution of searchable key-value stores.

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Open Source Search FTW!
Grant Ingersoll
Lucene/Solr Committer, Apache Soft.
Found.
CTO, LucidWorks
@gsingers

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Preaching to the Converted!
• Embrace fuzziness!
• Search is a system building
block
• If the algorithms fit,
use them!
• Search use leads to search
abuse
• Scoring features are
everywhere
http://cheezburger.com/5243950080

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Topics
• Quick Intro to Lucene and Solr
• What‘s new in Lucene and Solr 4.x?
- Lucene/Solr for Info Retrieval
• (Ab)Using Search Engine Tech. for Fun and Profit

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Quick Intro to Lucene and Solr

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Relax, You’re Among Friends
• Large, diverse search community with many non-traditional
search engine usages
- Object stores, Record linkage, Social, mobile -> web
• Open Dev. > Open Source
• ―The Apache Way‖
- Meritocracy – Those who do, decide!
• Always Be Testing
- Randomized system tests are all the rage
- http://vimeo.com/32087114
• Patches Welcome!

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Lucene: Speed and Memory
• Native Near Real Time (NRT) support
- Per segment
- FieldCache can be controlled to only load new segments
- Soft commit -- faster without fsync, allows quicker update
visibility
• DWPT (Document Writer per Thread)
- Faster more consistent index speed
• Faster fuzzy & wildcard query processing
• String -> BytesRef
- Much improved data structure
- … means less memory and less garbage collection effort

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Up and to the Right
• http://people.apache.org/~mikemccand/lucenebench/in
dexing.html
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Lucene: Flexibility
• Flexible Index Formats
- New posting list codecs: Block, Simple Text, Append (HDFS..),
etc
- Pulsing codec: improves performance of primary key searches,
inlining docs, positions, and payloads, saves disk seeks
• Pluggable Scoring
- Decoupled from TF/IDF
- Built in alternatives include BM25 & DFR, and others
» http://en.wikipedia.org/wiki/Okapi_BM25
» http://terrier.org/docs/v3.5/dfr_description.html
- Add your own

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FS(A|T)
• Keys:
- byte[] – write-once
- Linear time build of min. automata (nlogn if not sorted)
- Compression
- Reverse lookups
- Weights (used for auto-suggest)
- Pluggable Algebra
• Uses:
- Term Dictionary, TokenStreams, Japanese, synonyms, spelling, others
- FuzzyQuery is 100x faster -- http://bit.ly/hgO65c
• More:
- http://slidesha.re/vKtpVA
- http://bit.ly/Pkjyu0
- ―Smaller Representation of Finite State Automata‖
» Proc. of the 16th Inter. Conf. on Implementation and Application of Automata, CIAA'2011,
vol. 6807, 2011, pp. 118—192.

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Solr 4: New Features
• Search/Faceting/Relevance
- New Relevance Function Queries (tf, df, others)
- Pivot Faceting
- Pseudo-join
- Improved Spatial (more later)
- Full support for Lucene Codecs, pluggable scoring
• Indexing
- New Update Processors, including scripting option
- Near real time
• Codec/Similarity support from Lucene 4
• Other
- New Admin UI

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Geospatial improvements
• Index shapes other than points (circles, polygons, etc)
• More complex interactions than point in a circle
• Indexing:
- "geo‖:‖43.17614,-90.57341‖
- ―geo‖:‖Circle(4.56,1.23 d=0.0710)‖
- ―geo‖:‖POLYGON((-10 30, -40 40, -10 -20, 40 20, 0 0, -10 30))‖
• Searching:
- fq=geo:"Intersects(-74.093 41.042 -69.347 44.558)"
- fq=geo:"Intersects(POLYGON((-10 30, -40 40, -10 -20, 40 20, 0
0, -10 30)))‖

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Scaling Solr
• Distributed/sharded indexing & search
- Auto distributes updates and queries to appropriate shards
- Near Real Time (NRT) indexing capable
• Dynamically scalable
- New SolrCloud instances add indexing and query capacity
- Supports re-balancing
• Reliable
- No single point of failure
- Transactions logged
- Robust, automatic recover
• http://wiki.apache.org/solr/SolrCloud

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New in 4.4 (just released)
• HDFS backed directory for storing index and
transaction logs in Apache Hadoop
• New Core discovery capabilities
• Schemaless/External Schema/Field Guessing
• Schema APIs
• Add documents from the Admin UI

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Hacking Search
Engines for Fun and
Profit
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… Find your Keys, Store Your Content
• Lucene/Solr is a fast key-value
store
- Bonus: search your values!
• NoSQL before NoSQL was cool
• Solr: distributed key/value
- Durable, Isolated, Redundant, Fast,
Real-time
- Joins, Column Storage
• Solr or Tika + Lucene can index
popular office formats
• Solr can backup/replicate and
scale as content grows

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… Find Love! Upsell! Cross-sell!
• Cross recommendation as search
- with search used to build cross recommendation!
• Recommend content to people who exhibit certain
behaviors (clicks, query terms, other)
• (Ab)use of a search engine
- but not as a search engine for content
- more like a search engine for behavior
• See Ted Dunning‘s talk from Berlin Buzzwords on Multi-
modal Recommendation Algorithms
- http://berlinbuzzwords.com/sessions/multi-modal-recommendation-
algorithms
• Go get Mahout/Myrrix or just do it in y(our) search engine

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… Avoid Delays

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… Time travel?
• Leverage Solr‘s new
spatial capabilities to
index non-spatial data,
such as time ranges
- Useful for Open Hours, Shifts,
etc.
• Query using rectangle
intersections
- q = shift:"Intersects(0 19 23
365)‖
https://people.apache.org/~hossman/spatial-for-non-spatial-meetup-20130117/

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Boldly go forth and rank!
• Faster
• More Flexible
• Easier than ever scaling
• More reliable than ever
• Reduced cost of experimentation

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• Lucene/Solr EU
Conference:
- Dublin, IE, November 4-7:
http://lucenerevolution.org/
- CFP Open Now
Where to Next?
• Lucene/Solr
- http://lucene.apache.org
- {java-user|solr-user}@lucene.apache.org
- SIGIR ‗12 Open Source Workshop
» http://opensearchlab.otago.ac.nz/paper_
10.pdf
• LucidWorks
- http://www.lucidworks.com
- Commercial support, products, etc. for
Lucene/Solr
• Me
- grant@lucidworks.com
- @gsingers on Twitter
- ―Taming Text‖ – Engineer‘s guide to open
source search and NLP
» http:///www.manning.com/ingersoll
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Credits
• All of the Lucene/Solr committers and contributors
• Polar bear: http://gaijinexplorer.blogspot.ie/2012/12/its-all-just-relaxing.html
• Volunteers: http://www.poconohealthsystem.org/?id=228&sid=1
• Not Hiring: http://naijaguardianjobs.com/wp-content/uploads/2013/03/Not-Hiring-
The-American.jpg
• Keys: http://www.flickr.com/photos/crazyneighborlady/355232758/
• Love: http://www.msruntheus.com/above-all-love-each-other-deeply/
• TARDIS: http://2.bp.blogspot.com/-
ysN8JskY4WM/UEZNhBywQKI/AAAAAAAABdg/gXE0A9OO6Mk/s1600/13881_do
ctor_who.jpg