Introduction to Service Oriented Architecture (SOA).
=> Web Services technology extended (WSDL, SOAP, UDDI) is used as solution implementation
=>and the Java (JAX-WS, OpenESB) is used as a development platform.
1.To SOA architecture.
2.SOA generalities
3. Service Definition
4.Extended Services Web & REST
5.Web Service Providers :
1.To SOA architecture :
* DCOM, CORBA, EJB, RMI, .Net Remoting, … are solutions for distributed application .
(Pb):
a. Interoperability if components use the same solution .
b.Transport Protocol need Network Configuration
c. specific data representation format .
(Solution) :
-Evolution of Distributed Application : (Client/Server>>Web Application>>SOA)
soa001.png
2.SOA Generalities :
-SOA : Service Oriented Architecture :
-SOA Paradigm : Search(ابحث ) , Publish(نشر) , Consume(استهلك)
3. Service Concepts :
3.1.Definition(Service) :
service is a distributed software component, exposing functionality with high added value of a business domain .
(un service est un composant logiciel distribué, exposant les fonctionnalités à fort valeur ajoutée d'un domaine métier [M.Baron])
3.2. Aspects of Service :
A.Contract standardized , B.loose coupling, C.abstraction, D.reusability, E.autonomy, F.stateless G.discoverability, H.composability
3.2.A.Contract standardized :
-it's contract between service Provider & service Consumer .
-There is 3 types of contract :
>>>Linked to Service Syntax : (Operations,Input & Output Messages...)
>>>Linked to Service Semantic : Definition of rules and constraints .
>>>Linked to Service quality:(time of response ....)
-is based on interoperability standards to facilitate dialogue(such as WSDL) .
3.2.B.loose coupling:
-Use of Messages(Exchanges between provider and consumers).
-Use of Orchestration.
3.2.C. Abstraction :
-The working of the Service is "black box".(boîte noire)
-The service contract must contain only the information relevant to its invocation.
==>ensure the predictability(القدرة على التنبؤ) of a service ,
3.2.D. Reusability & discoverability:
-The service is accessible through a directory(annuaire) to facilitate its discovery .
3.2.E. Autonomy & Stateless(sans état) :
-Service shouldn't have dependency with another External Service .
-Ensure Autonomy of Service ===> Ensure its Predictability .
-Service should be stateless to minimize resource consumption .
3.2.F.composability:
-service must run in a modular way and not integrated. .
-Orchestration ensure composability of services .
4.Extended Services Web & REST
Two families of web service:
4.a.Extended Web Service:
>> Directory : UDDI ,
>>Contract :WSDL .
>>Consume : SOAP .
Stack of Standars :
4.b.REST Web Service :(Representational State Transfer) :
-Used fro DOA(Data Oriented Architecture)
-Use directly HTTP instead of SOAP envelope.
-Use URI to identify resource .
-Use HTTP Methods(GET,POST,PUT,DELETE) to Perform CRUD operations .
Stack of Protocols& Langages for REST :
5.Web Service Providers :
Tow Types :
>>Web Oriented Provider :=>Public
>>Entreprise Oriented Provider :
Reference :
No comments:
Post a Comment