This presentation discusses techniques for modeling, analyzing, synthesizing, and characterizing service behavior. It introduces modeling service behavior formally using Petri nets and automata for precision. It covers analyzing behavior for compatibility using state space verification. It also discusses synthesizing partner behavior to ensure controllability and characterizing partners using operating guidelines for discovery and substitutability. A variety of problems are addressed including composition, adaptation, diagnosis, repair, and realizability.
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This presentation:
• Part I: m3 techniques
0: modeling behavior
1: analysing behavior
2: synthesizing behavior
3: characterizing behavior
• Part II: n∞ problems
compatibility, controllability, substitutability, transformation, public
view generation, instance migration, uncontrollability diagnosis,
choreography repair, adaptation, test case generation, discovery,
composition, validation, realizability
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Modeling Behavior
Service
real world: WS-BPEL, BPMN, UML-ACT, ...
Model
formal semantics
Petri nets, automata, ...
Why?
precise meaning
independency of
language evolution
abstraction from
irrelevant details
find ambiguities/
inconsistencies
?€
?C ?T
!B !B[BPM 05,WS-FM 07,LNCS ToPNoC II]
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Modeling Behavior
Service
real world: WS-BPEL, BPMN, UML-ACT, ...
Model
formal semantics
Petri nets, automata, ...
Fact
We use feature
complete
semantics:
-links
-fault handling
-compensation
-events
?€
?C ?T
!B !B[BPM 05,WS-FM 07,LNCS ToPNoC II] implemented:
BPEL2oWFN
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1 Analying Behavior
= Compatibility
Service Service
?
implemented:
LoLA
several compatibility notions:
-deadlock freedom
-weak termination (always possible)
-strong termination (eventually will)
-coverage of activities
-other constraints
How?
state space
verification
[BPM 06,WS-FM 07]
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1 Analying Behavior
= Compatibility
Service Service
?
LoLA can do the job:
•soundness of 868 real business processes:
av. 4ms per process
•BPEL4Chor choreographies with
>1000 service instances
Why?
concurrency partial order reduction
replicated instances symmetry method
acyclic behavior sweep-line method
[BPM 06,WS-FM 07]
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2 Partner synthesis
Service
?
implemented:
(Fiona), Wendy
several controllability notions:
-centralized
-decentralized
-autonomous
[EMISA 05, LNCS ToPNoC II, IPL 08]
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3 Partner characterization
Service
??
?Provided
Service
Service
Requester
€
C T
Public View
•coin falls
•activate buttons
•evaluate pressed
•heat water
•fill cup
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3 Partner characterization
Service
??
?Provided
Service
Service
Requester
€
C T
Operating
Guidelines
•enter coin
•press button
•take cup
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Mediation (Adaptation)
Service
implemented:
MarleneHow?
partner synthesis
specification of
semantical constraints
Service
Service
create:
ack: + password: -
copy:
e-mail: + book: -
transform:
mtrsfeet:+ mtrs€:-
...
[submitted]
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partner
Test case generation
implemented:
as hackHow?
select cases from
operating guidelines
of spec
Service
Spec
Service
Impl
partner
partner
Why?
testing without
a partner misses
subtle errors
[WESOA 08, ZEUS 09]
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implicitly covered:
• service discovery
– characterization, matching, public view
• service composition
– compatibility, mediation, partner synthesis, repair
• validation
– controllability, characterization, diagnosis
• n ∞
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Current Work
• Behavioral Querying
– represent a query by an annotated automaton,
organise registry accordingly
• Other Correctness Criteria
– from deadlock freedom to weak termination
• Split Workflows into Services
• More Problems to Cover