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Federated Application Federated Application Integration with Web Integration with Web
Services:Services:
Case of MultiCase of Multi--Participant Cargo TraParticipant Cargo Transportationnsportation
Haoxiang Xia
Japan Adv. Inst. Sci. &Tech.
Shuangling Luo
Dalian Univ. Tech.
Taketoshi Toshida
Japan Adv.Inst. Sci. &Tech.
OutlineOutline
A real-world application case: multiparty A real-world application case: multiparty shipments tracking with Web Servicesshipments tracking with Web Services
Current Efforts of Web Service integration Current Efforts of Web Service integration (composition, orchestration, (composition, orchestration, choreography…)choreography…)
Federated Application Integration Model Federated Application Integration Model with Web Serviceswith Web Services
Application Case: Application Case: Multiparty Shipments Multiparty Shipments
TrackingTrackingScenario:
Coordinated by a transport agent, multiple cargo transportation companies collaboratively freight a bunch of cargos, from one city to another, or from one country to another.
Transport/Inventory Service Providers
Transport Process
User (cargo owner)
inquiring
coordinating
participating
TransportAgent
WS-based SolutionWS-based Solution
Cargo owner
Browser-based Query InterfaceBrowser-based Query Interface
TransportAgentCargo
Status DB
Shipments Tracking System
of Company A
Shipments Tracking System
of Company B
Shipments Tracking System
of Company n…
Status reportWS A
Status reportWS B
Status reportWS n
Status Listener
DB updater
Reporter-Listener Reporter-Listener MechanismMechanism
Reporter-Listener mechanism for Interactions Reporter-Listener mechanism for Interactions between WS of Transport Service Providers and between WS of Transport Service Providers and the Transport Agentthe Transport Agent
CargoStatus
TrackingSystem
of a
partici-pator
Cargo Status
Status Report WS
Status Report
Generator:XML
-basedDoc.
Status Reporter
JAXM-based Listener:Handling response or fault
JAXM-basedListener: receivingstatus change info
DB Updater
Error?
Error Msg Generator
Status Listener
Observations from the Observations from the ExampleExample
1) From business point of view, this example implies the Web Service support for a virtual enterprise
Transport/Inventory Service Providers
Transport Process
User (cargo owner)
inquiring
coordinating
participating
TransportAgent
Invisible to user
Facing a single company
A Virtual Enterprise
Observations from the Observations from the ExampleExample(cont.)(cont.)
2) From technology point of view, the key problem to support virtual enterprises is the inter-organizational IT application integration, or “Business-to-Business Integration” (B2Bi).
In the case of Web Services, the major challenge is inter-organizational Web Services integration.
Observations from the Observations from the ExampleExample(cont. 2)(cont. 2)Requirements:
• interoperable – Services should be easy to interconnect with each other to complete the overall goal;
• Adaptable to changes of business processes – currently supports long-running processes, short-running inter-organizational processes need to be supported too. process prone to change in temporary collaborations, e.g.,
new company participate an existing virtual enterprise; a company leaves the integrated process; or, the integrated process ends
Current Efforts for WS Current Efforts for WS IntegrationIntegration
Two families of work:
1)Composite Ws description in the Semantic Web Services community, e.g. DAML-S/OWL-S;
2)Web Service Orchestration and Choreography
BPEL4WS Abstract BPEL4WS Abstract ProcessesProcesses WSCIWSCI
BPEL4WS BPEL4WS Executable Executable ProcessesProcesses
BPMLBPML
Collaborative Protocols
Executable Processes
Source: C. Peltz, 2003 (HP White Paper)
Current Efforts: Current Efforts: OWL-S Composite OWL-S Composite
ProcessesProcessesThe Process Ontology of OWL-S describes the construction of composite processes
Source: www.daml.org
Current Efforts: BPEL4WSCurrent Efforts: BPEL4WSBPEL4WS is a typical example of the Web Services Composition technologies in the WS Orchestration and Choreography community.
• Proposed by IBM, Microsoft, and BEA;
• Combine and extend XLANG (Microsoft) and WSFL (IBM)
• Essentially describe syntax of WS interactions
• Follow a centralized orchestration model of WS composition and integration --- the integrated process is edited in a central control point and executed by a BPEL Engine, which invokes the participating Web Services.
Current Efforts: BPELCurrent Efforts: BPEL
Centralized Orchestration Model of BPEL(Source: BPEL4WS Introduction article at IBM alphaworks,2003)
BPEL Execution Engine
Limitations in Current Limitations in Current EffortsEfforts
All the work essentially aims at describing WS interactions at the coding level (e.g. describing how a message passes from one service to another, as well as the execution sequence of a series of services for completing a specific task or process);
BPEL and BPML imply a central control model for WS orchestration; WSCI declares to support more collaborative mode of WS interactions, but it itself does not provide the underpinning mechanism of how to support collaborative interactions.
Federated Application Federated Application Integration with Web Integration with Web
Services: InfrastructureServices: Infrastructure
App 1
App 2
The Internet
WS 1
interfacing
publishing
WS 2WS 3App 3
The Web of Services
Serve for users (user groups) assimple or compositeservices
?
Basic Ideas of FAIBasic Ideas of FAI Inter-organizational integrated processes are formed from bottom up by the participating organizations:
• Each organization takes the full responsibility of simple and composite Web Services (processes) bounded to it;
• Recursive composition of composite processes from simple operations, using BPEL4WS, WSCI or OWL-S;
• Decentralized orchestration of Web Services /processes for inter-organizational processes.
“Federated” integration means: 1) each organization manages and runs its own Services /inner-processes;
2) Simultaneously, it participates interactions with others
Recursive Service Recursive Service CompositionComposition
In business process modeling, the fundamental elements are “actions” ( in WSCI term) or “atomic processes” (in OWL-S term), which can be embodied as an executable “operation” of a Service.
Composite processes are comprised of a series of actions from some control construct ( basically “Sequence”, “Split”, and “Cycle”…) --- thus, the structured programming model is applicable for constructing a composite process: simple actions group into a module or composite process, composite processes form larger composite processes…
Recursive Service Recursive Service CompositionComposition
Observing from outside, composite and simple processes are not distinguishable
Decentralized Inter-Decentralized Inter-Organizational WS Organizational WS
OrchestrationOrchestration1 Participating organizations publish simple and
composite services (processes) so as to potentially be used by the collaborators;
2 Composite services can be comprised of internal services, and they can also be comprised of internal and external services (services that are from another organization);
3 Central control point is replaced by multiple orchestration points that are respectively owned and maintained by the participating organizations.
Decentralized WS Decentralized WS Orchestration:Orchestration:
Demonstrative ExampleDemonstrative ExampleCompany A
Company B The Internet
WS A1
Composite WS B5B1 B2
B3
B4
WS A2
Orchestrated Process A3
A1 B5 A3
Runtime Engine at Company A
WS C1
Company C
Orchestrated Process C2
A3 C1
Runtime Engine at Company C
Further Considerations for Further Considerations for FAIFAI
For business process integration, the key concept is that each participating company takes the responsibility of its own parts of the overall process; and the overall process is then formed from bottom up.
Each company maintains the interactions with the companies that directly interact with it, ignoring those not being directly connected.
Flexibility and Agility of the entire process would be increased, comparing with the centralized orchestration model; more suitable for temporary organized virtual enterprises or communities.
Further Considerations for Further Considerations for FAIFAI
Company A
The Internet
WS A1
Company B
B1 B2B3
B4
WS A2
Orchestrated Process A3
A1 B5 A3 WS C1
Company C
Orchestrated Process C2
A3 C1Influenced
Influence extends to
Find a new collaborator
Company D
B1 B2B3
B4
Further Considerations for Further Considerations for FAIFAI
The leaving of Company B in fact influences its direct collaborator (Company A). Company C needs do nothing. When Company A recovers the Process A3, the entire process is recovered too.
This concept resembles the localization principle of programming – try the most for avoiding local changes spread to the global structure.
Concluding RemarksConcluding RemarksCurrent work is at a very primitive stage, just on conceptualization.
• Test with more realistic application fields (medical information systems)
•Implementation of the entire framework.
for WS interactions, existing technologies of SOAP WSDL WSCI BPEL4WS are applicable.
need to integrate with data transfer standards, connects to ebXML, RosettaNet,…?
consider Inter-organizational mutual “understandings” of WS, at syntactic, semantic, and pragmatic levels?