My keynote for the SALAD2015 wokshop at ESWC2015)

1. the story so far
Services and Applications over Linked APIs and Data
workshop at the 12th Extended Semantic Web Conference
Portorož, June 1, 2015
semantics
on services

2. Who Am I?
Partner Technology Manager at Redlink GmbH
also…
External Lecturer at Fachhochschule Salzburg
Member of the Apache Software Foundation
previously…
Senior Researcher at Salzburg Research
Research Engineer at Fundacion CTIC
Sergio Fernández
@wikier
http://linkedin.com/in/sergiofernandez
http://www.wikier.org

3. - 10+ years experience in software
engineering;
- participated in 20+ international
research projects;
- successfully deployed 50+ industrial
solutions;
- co-founded 3 Apache projects.
the team
Redlink GmbH is a Austrian startup, headquartered in
Salzburg, that provides cloud services for Content
Analysis, Linked Data Publishing and Semantic Search.
@RedlinkGmbH
http://linkedin.com/company/redlink-gmbh
http://redlink.co
Who Are We?

4. Redlink offers
named-entity
recognition and
linking, topic
classification, fact
extraction and topic
classification from
textual and media
documents in
different languages.
Text Analysis &
Entity Linking
Linked Data
Publishing
Application
development
Enterprise Data
Linking
Redlink offers
services to build your
own applications by
combining existing
analysis tools and
datasets.
Redlink offers
cleaning,
transformation and
reconciliation of
legacy enterprise data
using open standards
and technologies.
Redlink offers data
management and
data publication
using open standards
Linked Data
technologies.
connect your content
with data that matters

5. semantics
on services
what have we achieved?

6. Service-Oriented Architectures
● Always aimed to enable the
development of applications by
combining loosely coupled and
interoperable services.
● Many technical proposals have came to
address the new problems that a
connected world requires.
● But beyond the syntax, the semantics
has been always the main issue for
services' interoperability.

7. Services _before_ Semantic Web
Semantics is a much bigger field than what
Semantic Web actually touches...
Them, of course, common SOA technologies
already have some sense of semantics:
● SOAP
○ WSDL
● etc...
● RPC
○ only on
failures
● CORBA
○ IDL

8. then back in 1989
Tim Berners-Lee
proposed the concept of
Semantic Web...
and since that
everything is
"semantically-enriched"

9. Semantic Web Services

10. Semantics Web Services proposals
● WSMO Stack
○ WSMO
○ WSML
○ WSMX
○ ...
● WSDL-S
● OWL-S
● SAWSDL
● etc..

11. REpresentational State Transfer
● REST revolutionized the Web providing an
effective mechanism to implement simple
Web APIs
● Simple data formats
○ XML at the beginning
○ JSON has overtook
● No formal protocol, no "official" standard,
just a set of conventions over HTTP
○ Therefore no formal semantics beyond the basic
operations / verbs
○ Simplicity is the key

12. where is my contract?

14. Read-Write Linked Data
2007 Linked Data Design Issues
http://www.w3.org/DesignIssues/LinkedData.html
2009 Read-Write Linked Data
http://www.w3.org/DesignIssues/ReadWriteLinkedData.html
2010 Linked Media Principles
http://bitbucket.org/srfgkmt/lmf/wiki/Principles-Linked-Media
2010 SPARQL 1.1 Graph Store HTTP Protocol
http://www.w3.org/TR/sparql11-http-rdf-update/
2011 Linked Data Basic Profile 1.0
http://www.w3.org/Submission/ldbp/
2012 Linked Data Platform 1.0
http://www.w3.org/2012/ldp/

15. a set of best practices and simple
approach for a read-write Linked
Data architecture, based on HTTP
access to web resources that describe
their state using the RDF data model
Linked Data Platform
Linked Data Platform 1.0
http://www.w3.org/TR/ldp/
W3C Recommendation 26 February
2015

16. L
D
P
https://www.flickr.com/photos/rachelpasch/3432013868

17. https://www.flickr.com/photos/sybrenstuvel/2468506922

18. HATEOAS
● Hypermedia as the Engine of Application
State is a constraint of REST
● Hydra aims to simplify the development of
interoperable Web APIs using
hypermedia controls
○ JSON-LD as pillar
● Some overlap (better resolved?) with LDP
○ containers and pagination
● Some good early results
○ e.g., Linked Data Fragments
● Still a lot of work to do in the W3C CG...

19. Glory of REST

20. What lies ahead...?
● Monolithic services do not scale
● Microservice architectures commonly
provide a better solution for Web-scale
problems
○ Services solving small concrete problems
○ Loosely couple
○ Low semantics on description
○ Stronger on business
● Open your mind
○ RDF is not the single data format
○ HTTP is not the single protocol
● Make easy for developers to jump in
● Test, learn, combine and test again

21. vision
https://www.flickr.

22. test yourself!
scientific evaluation is
not the way to validate
a solution against real
world problems

23. questions / discussion

24. hvala!
https://www.flickr.com/photos/hanspoldoja/1218526964/