A talk I gave at the Semantic Technology & Business Conference in London, 26 September 2011 ( http://semtechbizuk2011.semanticweb.com/sessionPop.cfm?confid=63&proposalid=4198 )

1. Evolving systems and
the link to service
orienta4on
...and the search for a shorter .tle
Angelo van der Sijpt
angelo.vandersijpt@luminis.eu
http://www.flickr.com/photos/artolog/313055444/

2. $ whoami
• Angelo van der Sijpt
• Commi:er with Apache ACE
• So=ware engineer at Luminis
Technologies
• angelo.vandersijpt@luminis.eu
• Buzzwords: Java, OSGi, Agile

3. ARL
http://www.flickr.com/photos/shonk/57302289/

4. Formal'
curriculum
• ...
• ... school's'objec+ves
curriculum personal)objec-ves
• ...
• ...
personal)learning)path

5. personal)learning)path
Goal%selec)on
Learning(
objec-ves

6. Learning(
objec-ves
Object'selec*on
Content
Executable*
learning
design
Execu&on

7. Formal'
curriculum
• ...
• ... school's'objec3ves
curriculum personal'objec3ves
• ...
• ...
personal'learning'path
Goal'selec3on
Learning(
objec-ves
Object'selec*on
Content
Executable*
learning
design
Execu&on

8. ARL
• “Where is this student compared to his class?”
ve
Re
a(
st
ric
or
pl
• “What learning style do I have?”
(v
Ex
ed
e
uc
pro .
file
• “Who else has problems with this?”
Educ.&
domain
• “What should I do now?”
http://www.flickr.com/photos/jeffsmallwood/233853485

9. The profile service
http://www.flickr.com/photos/crazyneighborlady/411869140/

10. • Pluggable
• Evolvable
• Driven by code

11. Query q = new Query()
.select(person())
.where(person().firstName(literal("Roy")));
RowSet<Row> rowSet = q.select(model);
Person roy = rowSet.iterator().next().get(person());
roy.lastName();
roy.lastName("Trenneman");

12. PIM:Person Subject9
Curriculum
hasTopConcept
SKOS:
hasEduca/on
Achievement
ha
f sA
O ch SKOS:Concept
sist iev
con ed
Educa/on Learing
Objec/ve

13. new Query().select(curriculum().label(), learningDimension(),
learningDimension().label(), achievement(),
learningdimension("sublearningdimension"))
.where(
curriculum()
.hasTopConcept(learningDimension())
.label()),
learningdimension("sublearningdimension")
.broader(learningDimension())
learningDimension()
.label(),
p.has(education()),
optional(
education()
.consistsOf(achievement()),
achievement()
.hasAchieved(learningdimension("sublearningdimension"))),
filter("bound(" + achievement() + ")");

14. Service Orienta4on
http://www.flickr.com/photos/camknows/4712191684

15. “A Service Oriented Architecture is comprised of
independently defined components, providing
services through agreed-­‐upon interfaces.
Components can in turn have dependencies on other
services.”
http://www.flickr.com/photos/camknows/4712191684

16. Service Orienta4on
• Mo.va.on
• Isola.on & decoupling
• (Coping with or causing) B A
dynamic composi.on
binding
• Vocabulary
• Service, component,
mandatory/op.onal
dependency • Excluded
• Rules • Discovery
• Services are self-­‐contained • Orchestra.on
• Interfaces are defined • Communica.on
beforehand method

17. http://www.flickr.com/photos/artolog/313055444/

18. Service
Module
Lifecycle
Framework

19. More on OSGi
• Defines a framework
• Bundles (components) are Java jar files
• Contain code, metadata, and arbitrary data
Hall
et al.
C rea tin g M odu lar
A ppl ica tio ns in J
ava
OSGi IN ACTION
Richard S. Hall
Karl Pauls
Stuart McCulloch
David Savage
FOREWORD BY PETER
KRIENS
MANNING
MANNING

20. SOA and data

21. • Code centric
• Data never dies, but code can go
• Plugging axioms and entailments

23. • Allows (de-­‐)installa.on of components
• Respects the service dependency tree
• Tradeoffs
• Transform data, or pay with code complexity

24. Versioning
Semantic Versioning
• Code: we’re ge[ng there Technical Whitepaper
Revision 1.0
May 6, 2010
• Major/minor/micro
• Ontologies: version from the
start
• Closed system? Place addi.ons in © 2010 OSGi Alliance
All Rights Reserved.
same version
• Open system? Bump version on
every change (but minimize those)

25. In short
• Code and data can learn from each other
• Evolve code and data together
• Package them together
• Consider your versioning scheme
• Do, or don’t, worry about interchangeability

26. Evolving systems and
the link to service
orienta4on
Angelo van der Sijpt
angelo.vandersijpt@luminis.eu
http://www.flickr.com/photos/98469445@N00/327471676/