We have identified issues related to composition of a business process and discussed the requirements for event-driven composition and event-driven service-oriented architecture.

1. Event-Driven Service-oriented Architecture (EDSOA)

2. Presentation Outline
2
Background
Introduction
Challenges
Related Work
Proposed Architecture
Model, Composition, and Deployment
Contribution
Conclusion & Future Work
2/16/2010 Event-Driven Service Oriented Architecture

3. Web Services
3
Definition by World Wide Web consortium (W3C)
“a software application identified by a URI, whose interfaces
and bindings are capable of being defined, described and
discovered as XML artifacts. A web service supports direct
interactions with other software agents using XML-based
messages exchanged via Internet-based protocols”
Registry
Producer Consumer
2/16/2010 Event-Driven Service Oriented Architecture

4. Web Service Interaction Pattern
4
2/16/2010 Event-Driven Service Oriented Architecture

5. WS* Stack
5
2/16/2010 Event-Driven Service Oriented Architecture

6. Web Services Composition
6
Business applications exposing their functionalities through web services
Developing and exposing Web Services is not sufficient. We need to
combine the functionality of several web services.
The process of developing a composite service is called service composition.
Service composition can be either performed by composing elementary or
composite services.
2/16/2010 Event-Driven Service Oriented Architecture

7. Introduction
7
A business process consists of a set of activities to provide a
specified servers..
Business processes require composition of services to fulfill its
goal, e.g. loan approval, Orderbook, generate result.
Business processes are driven by events and dynamic in nature.
Service-oriented Architecture (SOA) is an extension to
distributed computing paradigms to publish, discover, invoke
software component as services and for loosely coupled
interoperable integration of distributed heterogeneous system.
2/16/2010 Event-Driven Service Oriented Architecture

8. Challenges
8
Dynamically changing business requires
Service description and discovery
Event-driven modeling and Composition
Adaptive to the changes (State, Event and Execution)
Heterogeneous partner infrastructure requires
Interoperability, common vocabulary
Vanilla Web Services are lacking these requirements.
Standards and specifications are syntax oriented
No semantic support to make it machine processable
Limited usability
2/16/2010 Event-Driven Service Oriented Architecture

9. Composition Approaches
9
Web Services Composition approaches
Static vs. dynamic
Model driven
Automated vs. Manual
Adaptive
Do not consider event and time parameters
Event is important for life cycle of a process
2/16/2010 Event-Driven Service Oriented Architecture

10. Event-driven SOA Lifecycle
10
2/16/2010 Event-Driven Service Oriented Architecture

11. Event-driven SOA Architecture
11
2/16/2010 Event-Driven Service Oriented Architecture

12. Event Driven Composition
12
Event-Condition-Action rule: when an event occurs, the
condition will be evaluated and action will be taken if
the condition is true.
RULE<RuleName>[(<parameter>,…)]
WHEN<Event Expression>
IF<Condition 1> THEN <Action 1>
…
IF<Condition n> THEN <Action n>
ENDRULE<RuleName>
2/16/2010 Event-Driven Service Oriented Architecture

13. Backward Chain Rule
13
Backward Chain Rule: Contains preconditions for the tasks
Backward Chaining Algorithm – Deals with the backward chain rules
and identifies the tasks that need to be executed.
Input: Backward Chain Rule
Output: A={A1,A2,A3,....An} where A1,A2...An are the activities that
need to be performed
begin
Task Pool TP = Φ //empty initially
for each rule r in BCR
{
if (r.pre-condition ∉ TP)
add r.pre-condition to TP
}
A= TP
end
2/16/2010 Event-Driven Service Oriented Architecture

14. Forward Chain Rule
14
Forward Chain Rule: ECA rules are define as a Forward Chain Rule
Forward Chaining Algorithm – deals with the forward chain rules and
identifies the order in which tasks need to be executed.
Input : ForwardChain Rules – FCR, A – set of activities that need to be
performed, initial task I
Output : P[n] where Pi ∈ A and P is the process schema
begin
Task Pool P = Φ //empty initially
Add I to P
temp=I
Label:
index_of_task = Search(A,temp)
//Search will return -1 if temp is not present in A
while (index_of_task ! = - 1)
{
forward_index = Search(FCR,P[index_of_task].taskname)
add FCR[forward_index].action to P
temp = FCR[forward_index].action
goto Label
}
end
2/16/2010 Event-Driven Service Oriented Architecture

15. Deployment: Grid Business Process
15
Grid Business Process: to capture the requirements of dynamic
business processes.
Grid computing utilize SOA to capture the requirements of a
business process.
Convergence of Web Services and Grid computing replace
OGSI functionality with web services based set of
specifications:
WS – Resource Framework (WS-RF)
WS – Notification (WSN)
2/16/2010 Event-Driven Service Oriented Architecture

16. Six-Step Process
16
1. Model the business process.
2. Develop WS-RF service using factory pattern.
3. Modification of wsdl files.
4. Insertion of header variables
5. Orchestration of a process
6. Execution of process in grid environments
2/16/2010 Event-Driven Service Oriented Architecture

17. Convergence of SW, WS and GS
17
Standards are syntax based
Semantic Business Services Business Ontologyof business process
Automation and Business Rules
Discovery Semantic Web
Domain Ontology and Rules
Dynamic Composition
Grid Business Process
Composition Business Process Modeling Web Services
state, transaction, event and notification
Event-driven Composition
Scalability, Execution and Monitoring
Business Services
Deployment Grid Services
Grid Services
Middleware support
2/16/2010 Event-Driven Service Oriented Architecture

18. Conclusion
18
We have identified issues related to composition of a business
process and discussed the requirements for event-driven composition
and event-driven service-oriented architecture.
We have implemented event-driven lifecycle (model, compose,
deploy, and execution) and proposed Event-driven Service-oriented
Architecture.
We have demonstrated realization of event-driven Service-oriented
Architecture with the use of policy, service level agreement, and
service grouping for effective coordination of resources
Creation of Virtual Organization (VO) based on the policy to allow
access and sharing of resources
Use of semantic and policy to provide better search, query, and
management
Context, content and contract based dynamic services selection
2/16/2010 Event-Driven Service Oriented Architecture

19. Thank You!
Contact Us -For more information:
Attune Infocom Pvt Ltd
www.attuneinfocom.com
contact@attuneinfocom.com
Phone : +91-79-40047259
Cell : +91-9737339652