Semwebbers, LODers, what PubSubHubbub can do for you (SemTech)

Digital Enterprise Research Institute www.deri.ie SemWebbers, LODers: What PubSubHubbub can do for you Alexandre Passant DERI, NUI GalwaySemTech 2011June 09 2011, San Francisco© Copyright 2010 Digital Enterprise Research Institute. All rights reserved.

AgendaDigital Enterprise Research Institute www.deri.ie   Real-time Web and Semantics   Push vs Pull   PubSubHubbub (PuSH), SemWeb and Linked Data   sparqlPuSH   SMOB   Twarql   Q/A

A *real-time* WebDigital Enterprise Research Institute www.deri.ie   Information is no longer static   The Social Web as an information stream (Twitter, 4sq, ...)   New trends in ubiquitous computing   Sensor data and the IoT –  Even the @towerbridge is Tweeting !   A new area for Citizen Sensing   Earthquake detection (WWW2010 paper)   Emergency management, reporting and monitoring (Mumbai attacks on Flickr, Twitter, etc.)   Opinion / trends mining (Box office prediction by HP labs) 3 of XYZ

Semantics and the real-time WebDigital Enterprise Research Institute www.deri.ie   Combining social stream, sensors and social data   What’s happening right now, sport-wise, 25km around here ? –  Geonames, Twitter, Dbpedia, etc.   Who in my social network, whatever the website we’re connected through, is currently in my hometown –  FOAF, Geonames, etc.   Any humidity issues in our server rooms in the US –  Sensors, Geonames, Legacy Enterprise Data, etc.   New architectures are required   Enabling pro-active notification based on triggers   Defining semantic triggers ? Yes, with SPARQL ! 4 of XYZ

Pull vs PushDigital Enterprise Research Institute www.deri.ie   Pull   Constant queries to various sources to get what’s new   Useless HTTP calls (API/RSS), risks of being banned (TOS), costs and maintenance Schema by M. Dabrowski, DERI 5 of XYZ

Pull vs PushDigital Enterprise Research Institute www.deri.ie   Push   Websites let me know when they have something relevant   Wait. Receive. Consume Schema by M. Dabrowski, DERI 6 of XYZ

PubSubHubbub (PuSH) at a glanceDigital Enterprise Research Institute www.deri.ie   Google’s approach to enable Push on the Web   http://code.google.com/p/pubsubhubbub   Based on Atom / RSS –  link rel=“hub” header for identifying Hub from a feed   Simple registration / notification approach –  Libraries available in various languages –  Open source code for PuSH hub   Broadcasting data through public hubs –  Use Google’s one, Superfeedr, or host your own (e.g. Enterprise distribution of content) 7 of XYZ

PubSubHubbub, SemWeb and LOD ?Digital Enterprise Research Institute www.deri.ie   Registrations and notifications of structured data   Efficient broadcasting of structured content at Web scale   sparqlPuSH   Pro-active notifications of changes in RDF stores   Real-time monitoring using SPARQL and PuSH   SMOB   Distributed microblogging   Syncing hubs with PuSH and SPARQL 1.1 Update   Twarql   Twitter stream analysis 8 of XYZ

sparqlPuSH at a glanceDigital Enterprise Research Institute www.deri.ie   sparqlPuSH   Combining SPARQL, SPARQL Update and PubSubHubbub for pro-active notifications of changes in RDF stores   Can be plugged on the top of any RDF store - http://code.google.com/p/sparqlpush/   Based on   SPARQL to register feeds based on query patterns   SPARQL 1.1 Update for triggers registration and detection   Atom and RSS to get feeds of related changes   PubSubHubbub for broadcasting changes 9 of XYZ

A 2-steps approachDigital Enterprise Research Institute www.deri.ie   A two-steps approach   Query registration   Change notification   A sparqlPuSH endpoint   Plugged on top of any RDF store (implementation-agnostic)   Registration can be done remotely, through an HTTP request sent to the sparqlPuSH endpoing   Notification is triggered as soon as relevant data appears in the store, loaded with SPARQL Update through sparqlPuSH   Clients must understand the rel=“hub” link in the feed header, and interpret notification from PuSH hubs 10 of XYZ

Query registrationDigital Enterprise Research Institute www.deri.ie 11 of XYZ

Example of query registrationDigital Enterprise Research Institute www.deri.ie   Identifying changes on a particular object   Be notified when something happens to ex:FooBar   Using the Changeset vocabulary by Talis 12 of XYZ

Query registrationDigital Enterprise Research Institute www.deri.ie 13 of XYZ

Conventions in query registrationDigital Enterprise Research Institute www.deri.ie   Using conventions to get a well-formatted Atom / RSS feed   Easier to read in standard aggregators   Mandatory elements   ?uri - their URI of the element(s) to be retrieved   ?date - their creation / modification date   Can be used to retrieve named graphs if content itself is not dated   Optional elements   ?label - their label   ?author - their author 14 of XYZ

Browsing available feedsDigital Enterprise Research Institute www.deri.ie   The sparqlPuSH UI   Lists available feeds, including timestamp of last update   Ability to create feeds from the interface 15 of XYZ

NotificationDigital Enterprise Research Institute www.deri.ie 16 of XYZ

Notification on data updateDigital Enterprise Research Institute www.deri.ie   SPARQL Update support   HTTP-Posting data to the sparqlPuSH endpoint –  Then loaded in the underlying RDF store –  Allows *real-time* identification (as opposed to cron-job)   Identifying relevant changes   Applying all registered queries to the updated dataset   Broadcasting changes   Using PubSubHubbub ! (Scalability and RT delivery) 17 of XYZ

ImplementationDigital Enterprise Research Institute www.deri.ie   Source code (PHP)   http://code.google.com/p/sparqlpush/ (BSD license)   Server   Connection to any SPARQL endpoint   Additional connector for ARC2 using the ARC2 API   Generating RSS or Atom feeds   Demo client   Registering / unregistering queries to remote interfaces   Receiving updates from registered feeds 18 of XYZ

SMOBDigital Enterprise Research Institute www.deri.ie   Distributed and Semantic Microblogging   Setup your own hub, own your data, broadcast it   Fully SemWeb based (RDF backend, RDFa, LOD, etc.)   http://smob.me Local SPARQL/Update   SMOB and PuSH ?   Broadcasting SPARQL 1.1 Update queries (in RSS feed) SMOB hub at http://apassant.net HTTP POST   Instant notification for your SPARQL/Update + HTTP POST followers http://twitter.com   Ability to broadcast content deletion SMOB hub at http://example.org 19 of XYZ

SPARQL 1.1 Update + RSS + PuSHDigital Enterprise Research Institute www.deri.ie 20 of XYZ

TwarqlDigital Enterprise Research Institute www.deri.ie   Twitter feeds through SPARQL   Entity extraction from Twitter feeds   Representation as Linked Data (SMOB Stack)   SPARQL queries + PuSH for notifications   Code and demos   http://wiki.knoesis.org/index.php/Twarql   http://bit.ly/twarql 21 of XYZ

Questions ?Digital Enterprise Research Institute www.deri.ie   Acknowledgements   Google Research Awards   Julie Anaya (SMOB + PuSH)   Pablo Mendes / Pavan Kapanipathi (Twarql)   Contact   alexandre.passant@deri.org   http://apassant.net   @terraces 22 of XYZ

http://mnemosyne.de-blog.jp	1296
http://apassant.net	144
url_unknown	17
http://spitfire-project.eu	16
http://translate.googleusercontent.com	10
http://flavors.me	9
http://webcache.googleusercontent.com	9
http://paper.li	4
http://cache.yahoofs.jp	3
http://www.spitfire-project.eu	3
http://twitter.com	3
http://www.slideshare.net	3
http://207.46.192.232	1
http://www.onlydoo.com	1
http://www.linkedin.com	1

Semwebbers, LODers, what PubSubHubbub can do for you (SemTech)

by Alexandre Passant

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