Service Discovery and Component Reuse with Semantic Interfaces

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Service Discovery and Component Reuse with
Semantic Interfaces

• Richard T. Sanders (SINTEF, Trondheim, Norway)
• Rolv Bræk (NTNU, Trondheim, Norway)
• Gregor v. Bochmann Daniel Amyot (SITE, Univ.
  Ottawa, Canada)

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Conclusion

• Service components with semantic interfaces can
  be described using UML 2.0 collaborations
• interface role behaviour including goal
  expressions
• Liveness properties can be evaluated
• improvement over static interfaces
• Helps reuse, service discovery and role learning

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Service oriented architecture

• a service is a collaboration between roles
• a role is the part an actor (agent) plays in a
  service
• a role describes a property of an actor
• actors may be involved in several services

Service component
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Role modelling principles
call A-B
Actor
Actor
CA
CB
user A
user B
Semantic interface
Service component
UML 2.0 Collaboration

• Validate interfaces behaviour rather than
  components
• Safety properties
• Liveness properties

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Service feature and a pair of semantic interfaces
modelled in UML 2.0
UserCall
Collaboration goal
Service feature
def goal Boolean A.VoiceCntTo(B) and
B.VoiceCntTo(A)
Semantic interface
Semantic interface
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Interactions
Collaboration goal
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Phases of a UserCall
UserCall
Invite
Collaboration goal
Calling goal VoiceCnt(A,B)
Busy
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Semantic interfaces with goals and role behaviour
Role goal

• Role behaviour is a projection, and not a
  complete behaviour (hence spontaneous output)
• UML 2.0 does not adequately describe interface
  behaviour (protocol state machines not
  satisfactory)

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Interface behaviour as transition charts
Role goal

• Caller and Callee are dual roles

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Adding WaitOnBusy feature

• CallerW and CalleeW are dual roles

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Safety requirements and subtyping
Removed ouput reduction
Added input extension
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Subtyping relationships
UserCall
Caller
Callee
extension
reduction
UserCallW
CallerW
CalleeW
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Using Semantic Interfaces
Y UserAgent
X UserAgent
Callee
Caller
Compatible UserCall.goal
yi
xi
Incompatible
Compatible UserCall.goal
W UserAgent
Z UserAgent
CalleeW
CallerW
Compatible UserCallW.goal
wi
zi

• Compatibility can be decided at design time
• Can be performed for types, not just instances

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Role negotiation pattern
Run-time role validation
X UserAgent
Y UserAgent
Caller
Callee
B
A
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Service role learning pattern
Result(idCallerW, provider)
X UserAgent
W UserAgent
Caller
CalleeW
BW
A
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Work done

• Role projection and validation
• Role projection and safety validation algorithms
  designed and implemented
• Jacqueline Floch Compositional approach to
  service validation (Thursday)
• Progress validation algorithms design and
  implemented
• To be integrated in the tools used at Teleservice
  Lab at NTNU

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Work to be done

• UML tool support for UML 2.0 collaborations
• Compatibility checking of role binding at design
  time
• Composition of role behaviour from semantic
  interfaces
• Humberto Castejón Behaviour synthesis from
  UML/UCM (Thursday)
• Middleware support for service discovery and
  selection
• Role validation / negotiation at run-time
• Define ontologies for semantic interfaces
• Application to industry cases
• EU IST project 2006-2008
• Semantic Interfaces for Mobile Services (SIMS)
• SINTEF, NTNU, WUT, Appear Networks, Gentleware,
  Amena,

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Conclusion

• Service components with semantic interfaces can
  be described using UML 2.0 collaborations
• interface role behaviour including goal
  expressions
• Liveness properties can be evaluated
• improvement over static interfaces
• Helps reuse, service discovery and role learning

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• Thanks for listening!