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Service Oriented Architecture
Concepts, Principles, Facts, Myths, Hype, Reality…Part 1
Adomas SvirskasVilnius UniversitySeptember 2005
Agenda
• SOA as a moving target• SOA from corporate point of view• BEA SOA Domain Model and Strategy• SOA from technical point of view
SOA is…• The latest fashion in IT architecture• “SOA represents the biggest change in enterprise IT
since the advent of the Internet.” Infoworld SOA Executive Forum
• "Service-Oriented Architecture is an IT strategy that organizes the discrete functions contained in enterprise applications into interoperable, standards-based services that can be combined and reused quickly to meet business needs.“ Bill Roth, BEA Systems
• “SOA is a specific architectural style that is concerned with loose coupling and dynamic binding between services” [5]
SOA Benefits (Promised) [6]• Allows IT to deliver services faster and align closer with
business• Leverage existing assets• Improved productivity, agility and speed for Business &
IT• Reduced development times and costs through re-use• Decreased integration costs and risks• Lower maintenance costs and higher data integrity• Allows business to respond quicker and deliver
enhanced user experience• Enables new ways to relate to employees, partners and
customers
SOA Expectations [4]
Q: What are the critical business or IT problems your company hopes to address using SOA?
Base: 261 respondents (those personally involved with SOA in their company)
24%26%
35%
53%59%
42%42%
45%47%
58%59%
63%
46%
0% 10% 20% 30% 40% 50% 60% 70%
More effective use of external service providers
Customer service initiatives
Enterprise portal initiatives
Composite applications
Custom application development
More effective integration with business partners
Data integration
Integration to existing applications
Business process implementation
More flexible architecture
Employee self service
Streamlined supply chain
Global sourcing
Tech points of pain
Business pointsof pain
Source – BEA sponsored research with InfoWorld, [4]
SOA Roots
• SOA has emerged as a consequence of business and IT drivers of the past decade
• Business factors– Outsourcing of non-core operations– Business process re-engineering
• IT factors– Importance of universal middleware– The Internet
SOA from Business Perspective
• Business processes (BP) of any company prescribe how products are manufactured and offered to the clients
• Speed of change in BP domain corresponds to the speed of change in product offers, i.e. affects chances of survival in highly dynamic markets
• Flexibility is reflection of company’s ability to adapt its BPs quickly
The Services
• The business partners offer their resources in the form of services
• A service is:– Some sort of publicised package of
functionality– Composable– Discoverable based on describing metadata– Usable by a mutually agreed contract
The Services Taxonomy• Component services: Simple atomic services
potentially acting on single enterprise resource (e.g., database, code, etc)
• Data services: Service providing data querying, combination and transformation for multiple data sources.
• Business services: Atomic services composed of combinations of component services and rules.
• Workflow services: Long lived business processes coordinating other services with external interactions
Virtual Enterprises (Organisations)
• The need for speed and flexibility forces to outsource parts of the business, find the best partners on demand and manage a network of collaborations
• A company becomes a virtual organisation in its essence
• Mergers/acquisitions also create VOs• Complex VOs are tricky to manage and
operate without suitable framework
Virtual Enterprises (Organisations)
• VOs can exist inside a large company as well as cross company boundaries
• The partners inside a VO have no direct authority to control each other, as a rule
• The partners offer their resources (forms vary greatly) to other partners
• The collaborations between the partners include a number of business transactions
• The partners are loosely coupled
VO Lifecycle
Identification
OpportunityIdentification
OpportunitySelection
Formation
PartnerIdentification
PartnetSelection
PartnershipSelection
Operation
Design
FinancialManagement
Marketing
Design
Marketing
Termination
OperationTermination
AssetDispersal
To Function Well SOA Needs…
Service Infrastructure
Meta-dataRepository
Service Registry
Management
MessagingServices
MonitoringServices
DataServices
SecurityServices
UserInteraction
Services
BusinessProcessServices
CompositionTools
WebApp
Presentation Logic
ApplicationClient
Browser
Clients
Databases
Mainframes
Data
Legacy App
Identity/Policy
Portal
WSRP
WSRP
WebServicesWebServices
Data Layer
Data
Identity/Policy
Data
Data
Data
Process
Process
Process WebServicesWeb
ServicesMobile
… an infrastructure [4]
SOA Infrastructure
User Interaction
Inte
grat
ed C
ompo
sitio
n En
viro
nmen
t
Security Services
Data and Information Integration
Message Services
Process Orchestration
Message ServicesService ManagerService Manager
Message ManagementMessage Management Service RegistryService Registry
Security ServicesFederated Identity ManagementFederated Identity Management
Distributed Application Security ManagementDistributed Application Security Management
User InteractionPortal Portal
Multi-channelMulti-channel
CollaborationCollaboration
Interaction ManagementInteraction Management
Moni
tor
Com
pose
Prev
iew
Inte
grat
ed C
ompo
sitio
n En
viro
nmen
t
Upda
teProcess Orchestration
Business Process ManagementBusiness Process Management
Business Activity ManagementBusiness Activity Management
Enterprise ConnectivityEnterprise Connectivity
Business RulesBusiness Rules
Business IntelligenceBusiness Intelligence
Composite Data ManagementComposite Data Management
Data and Information Services
Unified Meta Data RepositoryUnified Meta Data Repository Unified Data ModelingUnified Data Modeling
more details [4]
SOA Solution Components [3]
• Producers: A producer is an entity that offers a specific service or functionality
• Consumers: A consumer is an entity that makes use of the service offered by the producer
• Services: A service is an entity that performs a specific task when invoked
• Contract: A contract or an interface specifies a format in which the data needs to be provided to the service to perform the specific task
• Repository: A repository is a glorified version of a registry and includes the metadata relevant for the solution, namely service, service contract, data/object model, and so on
Governance
• Governance is the management of development artefacts (or assets), such as Java code, HTML, XML, deployment descriptors, WSDL, etc.
• Governance is primarily about tracking and controlling development artifactsthrough their life cycles; from creation to archiving (it is usually not a good idea to destroy an artefact).
Debunking SOA Myths [3]
• Myth #1: SOA is a solution (panacea, silver bullet) to all software problems
• Myth #2: SOA is like a product, and can be downloaded for trial
• Myth #3: SOA is a complete, off-the-shelf solution
• Myth #4: SOA software always needs to be developed using Web services
Debunking SOA Myths [3]
• Myth #5: Any software development using Web services is aligned with SOA
• Myth #6: Each service is always atomic in nature
• Myth #7: SOA is not aligned with any standards
• Myth #8: SOA is the same as EAI• Myth #9: SOA is a very expensive solution
Debunking SOA Myths [3]
• Myth #10: SOA solution components (services, contracts) are completely reusable
• Myth #11: Services in the context of SOA are not explicit
• Myth #12: SOA is applicable only to specific industrial domains
• Myth #13: SOA can be sold to customers as is
Conclusions
• SOA has many shapes and forms• Domain Models, patterns and best
practices for SOA start to emerge• The first SOA-based corporate solutions
go live• SOA will attract more attention in the next
few years
References• [1] Foster, I. et al. Open Grid Services Architecture V1. 2004.• [2] Booth, D., et al. Web Services Architecture. W3C, Working Draft
http://www.w3.org/TR/2003/WD-ws-arch-20030808/, 2003.• [3] Anantharangachar, R. Myths About Service-Oriented Architecture, Web Services
Journal, August 2005• [4] Carges, M. Taking SOA from "Pilot to Production" with Service Infrastructure
http://www.infoworld.com/event/soa/InfoWorld_SOA_Mark_Carges.ppt• [5] Curbera, F. et al., Web Services Platform Architecture: Soap, WSDL, WS-Policy,
WS-Addressing, WS-Bpel, WS-Reliable Messaging and More, Prentice Hall PTR, 2005
• [6] Kamdal, M. SOA – Taking a Structured approach. BEA Architects Summit, http://ftpna2.bea.com/pub/downloads/architectsummitpresentations/SOA_Taking_A_Structured_Approach.pdf
• [7] Roth, B. Service-Oriented Architecture Best Practices, http://java.sys-con.com/read/48032.htm