Online recommendations at scale using matrix factorisation
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Thesis presentation: Online recommendations at scale with matrix factorisation . Royal Institute of Technology, Stockholm, Sweden Instituto Superior Técnico, Lisbon, Portugal Universitat Politécnica de Catalunya, Barcelona, Spain 22 June 2012 Marcus Ljungblad [email protected]
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This presentation was used for my thesis defense held at Universidad Politecnica de Catalunya, Spain, for a double-degree master programme in Distributed Computing. The other two universities participating in the programme are Royal Institute of Technology, Stockholm, Sweden and Instituto Tecnico Superior, Lisbon, Portugal.
Transcript of Online recommendations at scale using matrix factorisation
Thesis presentation:
Online recommendations at scale with matrix factorisation.
Royal Institute of Technology, Stockholm, SwedenInstituto Superior Técnico, Lisbon, PortugalUniversitat Politécnica de Catalunya, Barcelona, Spain
22 June 2012Marcus Ljungblad
75% of the 30 million daily movie starts are sourced from recommendations."
a key differentiating factor"
3 challenges
How do you serve recommendations from millions of items to millions of users online?
2 4 4 ? 13 5 ? ? 1? 4 2 1 ?
1 ? 1 3 3
Video ratingsU
sers
f( )
2.05 3.97 3.96 2.12 1.012.93 5.02 3.21 1.61 0.982.15 3.95 2.01 1.05 1.10 1.00 4.29 1.01 2.96 2.98
Video ratingsU
sers
2.05 3.97 3.96 2.12 1.012.93 5.02 3.21 1.61 0.982.15 3.95 2.01 1.05 1.10 1.00 4.29 1.01 2.96 2.98
Video ratings
Use
rs
2 4 4 ? 13 5 ? ? 1? 4 2 1 ?1 ? 1 3 3
2.05 3.97 3.96 2.12 1.012.93 5.02 3.21 1.61 0.982.15 3.95 2.01 1.05 1.10 1.00 4.29 1.01 2.96 2.98
13x40M I L L I O NR A T I N G S
Interface Delegate Router Worker
requeststart
route
compute
top-N
to jsonreply
merge
Interface Delegate Router Worker
requeststart
route
compute
top-N
to jsonreply
merge
Did it work?
Setup:
• 1-3 machines
• 1 million items
• same rack = high-speed
• 1 test machine
Performance!
Performance!
huh?!
Did it work?wel
l
74% = 74%Offline Online
Summary:
... clustering depends on data ...
... need balanced clusters ...
... memory bound ...
... scales ok ...
Thank you!
Photos and pictures borrowed from the Internetz:
Iron Maiden cover: http://en.wikipedia.org/wiki/File:Iron_Maiden_(album)_cover.jpgCat picture: http://www.lastfm.es/group/CatsCoins: http://www.sxc.hu/photo/1235540iPhones: http://blog.bayuamus.com/2011/08/user-experience-comparison-between-htc-salsa-and-samsung-galaxy-mini/Amazon recommendations: http://mashable.com/2010/08/06/online-retail-facebook-data/TV remote: http://www.flickr.com/photos/62337512@N00/2749561795/sizes/z/in/photostream/Headphones: http://www.flickr.com/photos/markusschoepke/82957375/sizes/m/in/photostream/Function: http://en.wikipedia.org/wiki/File:Graph_of_example_function.svgHome servers: http://www.flickr.com/photos/fabrico/477844434/sizes/z/in/photostream/
Extra material...
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