Download Separating Operational and Control Behaviors

Separating Operational and
Control Behaviors
Quan Z. Sheng , Zakaria Maamar , Hamdi Yahyaoui ,Jamal Bentahar
and Khouloud Boukadi
Internet Computing, IEEE
May-June 2010
Volume: 14 Issue:3
On page(s): 68 - 76
SSE 3200
Luke Gesior
Jeremy Strandberg
Problems
Web Services are confined to simpler
applications
 WSDL does not show how to oversee
executions
 Design Soundness-Conversation
Deadlocks
 Difficult debugging and testing

What are Web Services?

application components

communicate using open protocols

self-contained and self-describing

used by other applications
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?
Web Services Description Language
 used to describe Web services

What is UDDI?
Universal Description, Discovery and Integration
 a directory for storing information about web
services

Separation

Operational Behavior
◦ Application-dependant
◦ Contains functionality

Control Behavior
◦ Application-independent
◦ Builds execution progress

Conversational Messages
◦ Convey information between the two
www.noaa.gov
Two Functions
Next(activated, path1) =
(commitment, done)
Next(activated, path2)=
(failure, aborted)
Conversational Messages

Seven 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 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
Example

Sync(str) handles (activated, label1 , inputcollected)
◦ Consists of strp1 and strp2
Conversation Sessions
Sequenced conversational messages
 Sync.Success
 Sync.Delay.Syncreq.Sync.Succes
 Some sequences lead to indefinite waiting

Solution
•
•
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 Implementation


Coded in Java
Consists 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
Questions
(mandatory)
References

Separating Operational and Control Behaviors
Quan Z. Sheng , Zakaria Maamar , Hamdi Yahyaoui ,Jamal Bentahar
and 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
NuSMV
Melissa KOVA1, Jamal BENTAHAR1, Zakaria MAAMAR, and HamdiYAHYAOUI

http://www.w3schools.com/

www.noaa.gov