Transcript Integratie Software Systemen - Institute for Computing and

Integratie Software Systemen
Alonso, Casati, Kunu & Machiraju
Web Services - Concepts, Architectures
and Applications
Hoofdstuk 5 – Webservices
Danny Romme (0213950)
Jan Vogels (0321389)
Waar gaat het over?
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Introductie Web Services (Jan)
Beperkingen conventionele middleware (Jan)
Essentiële concepten Web Services (Jan)
Overzicht middleware (Danny)
Web Service architecture (Danny)
Definitie (1)
Verscheidene definities van algemeen tot specifiek
 Definitie van het UDDI consortium: “self-contained,
modular business applications that have open, Internetoriented, standards-based interfaces”
 Nadruk op standaarden en internettoegang
 Niet precies genoeg
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Definitie (2)
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Definitie van W3C: “a software application identified
by a URI, whose interfaces and bindings are capable of
being well-defined, described, and discovered as XML
artifacts. A web service supports direct interactions with
other software agents using XML-based messages
exhanged via Internet-based protocols”
Definitie (3)
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Definitie van Webopedia: “a standardized way of
integrating web-based applications using the XML,
SOAP, WSDL, and UDDI open standards over an
internet protocol backbone. XML is used to tag the data,
SOAP is used to transfer the data, WSDL is used for
describing the services available, and UDDI is used for
listing what services are available”
Definitie (4)
Webopedia definitie specificeert standaarden
 Standaarden vormen niet de essentie
 Boek hanteert W3C definitie
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B2B Integratie
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Voorbeeld supply chain
web
server
internal procurement
requests
internal
infrastructure
internal
infrastructure
web
server
internal
infrastructure
warehouse
B2B interactions
occur by accessing
Web pages, filling
Web forms, or via
email.
Limitations of Conventional
Middleware in B2B Integration
Conventionele middleware in voorbeeld niet
handig
 1 middleware systeem
 Implementatie global workflow
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Limitations of Conventional
Middleware in B2B Integration (2)
third party
a “global” workflow is executed
here
WfMS
WfMS adapter
message broker
customer
supplier
customer’s
adapters
internal procurement
requests
internal
infrastructure
the combination of message
broker and adapters enables
interoperability
supplier’s
adapters
warehouse
warehouse’s
adapters
internal
infrastructure
internal
infrastructure
Limitations of Conventional
Middleware in B2B Integration (3)
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Conceptueel mogelijk, maar praktisch lastig
Gebrek aan vertrouwen (Lack of trust)
Autonomie
Confidentialiteit
Mogelijke oplossing: Point-to-point
Point-to-Point (1)
customer
message broker
XYZ
customer’s
adapters
internal
infrastructure
supplier
message broker
XYZ
supplier’s
adapters
internal
infrastructure
Point-to-Point (2)
Waarborgt confidentialiteit
 Voor elke partner nieuwe afspraken
 Heterogeniteit
 Integratie noodzakelijk
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Point-to-Point (3)
customer
warehouse
another party (XYZ)
yet another party
(ABC)
middleware for
supplier-customer
interaction
middleware for
supplier-warehouse
interaction
middleware for
supplier-XYZ
interaction
middleware for
supplier-ABC
interaction
supplier’s
adapters
supplier’s
adapters
middleware for integrating
the middleware
supplier
supplier’s
adapters
internal infrastructure
Middleware perikelen
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Conventionele middleware schiet te kort
EAI transacties meestal van korte duur
Transacties tussen organisaties vaak langer van
duur
Asynchroon
Locking van resources
Gebrek aan vertrouwen
Integration before Web Services
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Fundament middleware: gecentraliseerd en veilig
Gaat niet op voor B2B
Point-to-point duur door gebrek standaardisatie
Enkele succesgevallen (Walmart)
Ad-hoc
Pogingen tot standaardisatie
Integration with Web Services (1)
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Bijdrage van het web
– service-oriented architectures
– redesign van middleware protocollen
– standaardisatie
Service-oriented architectures
Aanroepbare procedures
 Aanroepen via web
 Niet elke service op het web is een webservice
 Webservice: software applicatie met gepubliceerde
en stabiele API
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Redesign Middleware protocollen
Conventionele protocollen moet herontworpen
worden
 Decentralisatie
 Confidentialiteit
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Standaardisatie
Noodzakelijk voor veelvuldig gebruikt
 Web services benadrukt belang van standaard
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Integration with Web Services (2)
customer
Web
service
internal procurement
requests
internal
infrastructure
interactions based on protocols
redesigned for peer to peer and
B2B settings
internal functionality made
available as a service
supplier
languages and protocols
standardized, eliminating need for
many different middleware
infrastructures (need only the
Web services middleware)
Web
service
internal
infrastructure
Web
service
internal
infrastructure
warehouse
Integration with Web Services (3)
Webservices dienen als entrypoints naar locale
informatiesystemen
 Communicatie gebeurt peer-to-peer
 Gestandaardiseerde protocollen als
gedecentraliseerde middleware
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Webservices en EAI (1)
Webservices als entrypoint
 Functionaliteit vinden en benaderen op
gecontroleerde manier
 Wrapper
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Web
service
Web
service
Web
service
middleware
internal
service
internal
service
Company A (provider)
wide area network (Internet)
Webservices en EAI
client
middleware
internal
service
Company B (client)
internal
service
Wrappers
Homogeen
 Kern middleware ondersteunende applicaties
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Locale webservice (1)
Webservice kan locaal zijn
 Integratie enterprise applicaties
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Locale webservice (2)
Company A (or a LAN within Company A)
integrating application (contains
the composition logic)
Web service-enabled broker
sendmail
application
SmartQuotation
assumes all back-end
systems are accessible
as Web services
DBMS
SmartForecasting
applications
XYZ
Web Services Technologies
Service Description
 Service Discovery
 Service Interactions
 Combining Web Services: Composition
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Service Description
properties and semantics
business protocols
interfaces
common base language
directories
vertical standards
Service Discovery
Service Interactions
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Transport
 Messaging
 Protocol Infrastructure (meta-protocols)
 Middleware (horizontal) protocols
Combining Web Services:
Composition
Web Services Architecture
The two facets of Web Services architecture
 Internal architecture of Web Services
 External architecture of Web Services
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Vragen?
Nee? Mooi!