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Agenda• Evolution to Web Services
– The need for business processes
• Understanding BPEL4WS– BPEL4WS in a Nutshell– Abstract Processes– Simple Scenario
• Using BPEL4WS– Implementing BPEL4WS– Quick walk-through– Typical BPEL4WS constructs
• Update on the OASIS BPEL4WS Technical Committee
Evolutionto
Web Services
Business BenefitBusiness Benefit
The Evolution to Web Services
Early 1990sApplication integration
technologies appearApplication integration
technologies appear
Late 1990sWeb technologies appear
e.g. HTTP, HTML, XMLWeb technologies appear
e.g. HTTP, HTML, XML
2000+Web application
technology = Web services
Web application technology = Web services
Pre-1990sCustom, staticCustom, staticB2B IntegrationB2B IntegrationCustom, staticCustom, staticB2B IntegrationB2B Integration
The Goal A standards-based architecture that is broad yet flexible enough to provide secure, reliable, transacted Web services messaging infrastructure
Web Services Overview
XMLXML
Your CompanyYour Company Internal SystemsInternal Systems
PartnersPartners CustomersCustomers
SOAPSOAPSOAPSOAPSOAPSOAP
Web Services OverviewWhat’s Missing?What’s Missing?
SecuritySecurity
Reliable MessagingReliable Messaging
TransactionsTransactions
Your CompanyYour Company
Good Progress…More To Do• Businesses need a model for describing how
individual Web services can be connected to create complex, reliable and dependable business processes
• This must enable...– Baseline transactional support– Interoperability between business processes and
business partners in heterogeneous environments– Interoperability between tools such that any supporting
tool can be used to author and analyze business processes
– Executability in each supporting environment
Web Services“Secure, Reliable, Transacted”
Business Processes
Business Process Execution Languagefor Web Services (BPEL4WS)
TransactionsReliable MessagingSecurity
Messaging
Web Services Description Language (WSDL)
Simple Object Access Protocol (SOAP)
Extensible Markup Language (XML)
Other protocolsOther services
Description
Quality of
Service
“BPEL4WS in a Nutshell”• A Turing complete language that can be used to specify behavior of
business processes – Between Web services...– ...and as Web services
• BPEL4WS is not a programming language– Exchange format for defining public behaviors (business protocols)– Export from one platform, import into another– BPEL4WS implementations leverage platform-specific strengths
• Abstract processes– Specify constraints of message exchange– Exposes only information required by partner
• Same language may also be used to define executable processes and business protocols – “Best practice” executable models?
BPEL4WS Dependencies
• XML 1.0
• W3C XML Schema 1.0
• WSDL 1.1
• XPath 1.0
• WS-Addressing • Every partner is assigned a unique
endpoint reference•
BPEL4WS• Extends and subsumes previous specifications in this area
published individually by Microsoft XLANG (05/01) and IBM WSFL (05/01)
• XML-based workflow definition language
• Describe business to consume/provide Web services in a reliable and dependable manner
• Portability and interoperability by defining a set of constructs to implement executable business processes and to implement message exchange protocol
BPEL4WS – Basic Concepts
• Peer-to-peer interaction between Web Services described in WSDL
• Process and partners are modeled as WSDL services
• BPEL4WS provides the process definition
What is an Abstract Process?
• Description of public behavior– Public face of private processes
• Independent of implementation
• Scenarios:– BigCo dictates trading partner requirements– Industry consortia provides guidelines for working together
BigCoBPELaBPELa
BPELaBPELa
BPELa BPELa
IndustryCommitte
e
Simple Scenario
• Goals:1. Allow customers to submit travel itineraries to travel agents;2. Automatically procure appropriate airline, hotel and vehicle
reservations for customer itineraries;3. Automatically return confirmation on all reservations back to the
customer once processing of the itinerary is complete; and4. Streamline cancellation procedure.
ReceiveItinerary
CustomerReserveFlights
ReserveHotel
Reserve Car
Airline
Wait ForConfirmation
Hotel
Car
NotifyCustomer
Simple Scenario
ReceiveItinerary
CustomerReserveFlights
ReserveHotel
Reserve Car
Airline
Wait ForConfirmation
Hotel
Car
NotifyCustomer
1. BPEL4WS: Define how to integrate the services of partners into business processes.
2. BPEL4WS: Define how specific activities of a business process can be exposed publicly as Web services, bridging the abstract and the executable.
BPEL4WS
• Expect most practical usage in– Design of business protocols (external behavior)– Design of best practices and templates (executable models)
• Realistic process implementations will need platform-specific resources
• Common model for “public” and “private” behavior– The boundary between private and public can shift
• Outsourcing, mergers, etc.
– Conformance relationships, export and import, is easier if the underlying set of core concepts is the same
• WSDL– Port types, services and messages (extensions)– Defined abstractly
• BPEL1. Partner Links
– Define partners, services
2. Variables– Globally visible, used to pass info, state, etc
3. Fault Handlers– Transfer of control during an exception
4. Activities– Process definition/description
BPEL and WSDL
What’s in BPEL4WS?
Correlation SetsCorrelation Sets
Fault HandlersFault Handlers
VariablesVariables
Business Process
Partner LinksPartner Links
ActivitiesActivities
Correlation
• Correlation identifiers are groups of properties embedded in messages
• Correlation is used between partners to identify process instances
• Different partners may use different correlation mechanisms
• Even for a single partner correlation mechanism might change in course of interaction
Activities<-! activity can be any one of the following: -->
<empty><invoke><receive><reply><assign><wait><throw><compensate><terminate><flow><switch><while><sequence><pick> <scope>
WSBPEL Technical Committee Update
About the WSBPEL TC• Technical Committee launched 5/15/2003
– BEA, IBM, Microsoft, SAP and Siebel submitted BPEL4WS V1.1 with royalty free terms
• Subcommittees:– Issues– Specification Editing– Use Cases– Liaisons– Implementation
• Liaisons with:– CEFACT Business Process WG– W3C Web Services Choreography WG– Others pending…
• Publicly available:– Archives– Spec, Issues List, Resources– Comment “web form”
Recommended Resources
• Start using BPEL today with BizTalk 2004– http://www.microsoft.com/biztalk/– Download a trial copy
• BPEL 1.1 specification (draft)• Goals of the BPEL4WS Specification• Abstract Processes in BPEL4WS• BPEL4WS Issues Tracking• BPEL4WS Use Cases
msdn.microsoft.com/library/en-us/dnbizspec/html/bpel4wsspecindex.asp
© 2003 Microsoft Corporation. All rights reserved. © 2003 Microsoft Corporation. All rights reserved. This presentation is for informational purposes only. MICROSOFT MAKES NO WARRANTIES, EXPRESS OR IMPLIED, IN THIS SUMMARY.This presentation is for informational purposes only. MICROSOFT MAKES NO WARRANTIES, EXPRESS OR IMPLIED, IN THIS SUMMARY.
