Separating Operational and Separating Operational and Control BehaviorsControl Behaviors Quan Z. Sheng , Zakaria Maamar Quan Z. Sheng , Zakaria Maamar , , Hamdi Hamdi Yahyaoui Yahyaoui ,,Jamal BentaharJamal Bentaharand Khouloud Boukadi and Khouloud Boukadi Internet Computing, IEEE Internet Computing, IEEE May-June 2010 May-June 2010 Volume:Volume: 14 Issue:3 14 Issue:3 On page(s): On page(s): 68 - 76 68 - 76

SSE 3200Luke Gesior Jeremy Strandberg

ProblemsProblemsWeb Services are confined to

simpler applicationsWSDL does not show how to

oversee executionsDesign Soundness-Conversation

DeadlocksDifficult debugging and testing

What are Web What are Web Services?Services?

application components

communicate using open protocols

self-contained and self-describing

used by other applications

What is SOAP?What is SOAP?

Simple Object Access Protocol

Format for sending messages

Designed to communicate via Internet

Allows you to get around firewalls

What is WSDL?What is WSDL?Web Services Description Languageused to describe Web services

Universal Description, Discovery and Integration

a directory for storing information about web services

What is UDDI?What is UDDI?

SeparationSeparationOperational Behavior

◦Application-dependant◦Contains functionality

Control Behavior◦Application-independent◦Builds execution progress

Conversational Messages◦Convey information between the two

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Two FunctionsNext(activated, path1) = (commitment, done)

Next(activated, path2)= (failure, aborted)

Conversational Conversational MessagesMessagesSeven Types

◦sync, ping, success, ack, fail, delay, syncreq

Initiation messages◦from control to operational behaviors◦start an execution

Outcome Messages◦from operation to control behaviors◦Report on executions status

Input ArgumentsInput Arguments• strp1 –Common Arguments– ID, Name, From, To, Trigger

• strp2 –Arguments from control to operational

behavior–Authorized activity-time, Authorized

passivity-time, Required Participants• strp3 –Arguments from operational to control

behavior–Counter-part ID, Effective activity time,

Execution Nature

ExampleExampleSync(str) handles (activated,

label1 , input-collected) ◦Consists of strp1 and strp2

Conversation SessionsConversation SessionsSequenced conversational

messagesSync.SuccessSync.Delay.Syncreq.Sync.SuccesSome sequences lead to

indefinite waiting

SolutionSolution• Represent every combination of

conversational messages• Integrate restrictions to

conversational messages–Each Delay message in a sequence

should be followed by a Success, Fail, or Syncreq message, that is, Delay(t) ⇒ Success(t + 1) ∨ Fail(t + 1) ∨ Syncreq(t + 1). –Each Ping message in a sequence

should be followed by an Ack message, that is, Ping(t) ⇒ Ack(t + 1).

• Ensures soundness of design

Conclusion and Conclusion and ImplementationImplementation

Coded in JavaConsists of four tools system engineers

access◦Control Behavior Modeler◦Operational Behavior Modeler◦Conversation Modeler

Takes web services behavior as input Produces conversation specification as output,

translated into XML◦Conversation Controller

Provides methods for managing conversations◦Service Manager

Allows engineer to track and analyze execution

QuestionsQuestions(mandatory)(mandatory)

ReferencesReferences Separating Operational and Control Behaviors

Quan Z. Sheng , Zakaria Maamar , Hamdi Yahyaoui ,Jamal Bentaharand Khouloud Boukadi Internet Computing, IEEE May-June 2010 Volume: 14 Issue:3 On page(s): 68 – 76

A Formal Verification Approach of Conversations in Composite Web Services using NuSMVMelissa KOVA1, Jamal BENTAHAR1, Zakaria MAAMAR, and HamdiYAHYAOUI

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