SERVICE ORIENTED ARCHITECTURE

                                                SERVICE ORIENTED ARCHITECTURE

UNIT 1

Definition of architecture along with types:

IT departments started to recognize the need for a standardized definition of a baseline application that could act as a template for all others. Its types are

i)                    Application Architecture – analogous to blue print of a Building

ii)                  Enterprise Architecture – analogous to urban plan of a city

iii)                Service Oriented Architecture

    List various Characteristics of SOA.

The following primary characteristics:

1. Contemporary SOA is at the core of the service-oriented computing platform.
2. Contemporary SOA increases quality of service.
3. Contemporary SOA is fundamentally autonomous.
4. Contemporary SOA is based on open standards.
5. Contemporary SOA supports vendor diversity.
6. Contemporary SOA fosters intrinsic interoperability.
7. Contemporary SOA promotes discovery.
8. Contemporary SOA promotes federation.
9. Contemporary SOA promotes architectural composability.
10. Contemporary SOA fosters inherent reusability

     Differentiate SOA vs Traditional Distributed Internet Architecture.

Distributed Internet application put all the application logic on the server side

Even client-side scripts are downloaded from the server

Entire solution is centralized

Emphasis is on:

a.      How application logic is partitioned

b.      Where partitioned units reside

c.       How units of logic should interact

In Service Oriented Architecture, Functionality is wrapped in services

Functionality is exposed via open, standardized interface, irrespective of technology providing the solution

Services exchange information via SOAP messages.  SOAP supports RPC-style and document-style messages

Most applications rely on document-style

      Compare SOA with client-server and distributed internet architectures.

 Service Oriented Architecture is an IT architecture Consisting of loosely coupled modular services that meets specific IT or Business Requirement.

While in Client-Server Architecture, applications cannot share data and resources and they act as an individual unit which cannot be reused or shared. If any change has to be made to the system,we have to recompile from scratch.

While in Distributed Internet Architecture,Functions and services are tightly coupled and hence reusability and interoperability becomes primary concern.

4.      What are the Logic components of the Web services framework?

The logic components of Webservices Framework are:

Messages = units of communication

Operations = units of work

Services = units of processing logic

Processes = units of automation logic

5.      What are messages, operations, services and processes?

Messages = units of communication

Operations = units of work

Services = units of processing logic

Processes = units of automation logic

6.      List the common principles of service-orientation.

i)                    Abstraction

ii)                  Loose Coupling

iii)                Service Contract

iv)                Autonomous

v)                  Reusability

vi)                Composability

vii)              Discoverability

viii)            Statelessness

7.      Are services reusable? Justify.

In Service Oriented Architectutre, Services can be reused.

For Example:

8.      Are services loosely coupled or tightly coupled? Justify.

In Service Oriented Architecture,Services are Loosely Coupled.

16 marks

1. Compare SOA with client-server and distributed internet architectures.
2. Explain in detail about various components of SOA and how they inter – relate to each other.
3. How components in an SOA inter-relate
4. Discuss in detail about the Common principles of service- orientation.

unit 2 

Definition of web service:

Web Service is a black box that provides specific functionality that can be exposed over the internet to be consumed by applications independent of Operating System, programming language and Component Model.

Characteristics of Web service framework:

The Web services framework is characterized by:

1. an abstract (vendor-neutral) existence defined by standards organizations and implemented by (proprietary) technology platforms
2. core building blocks that include Web services, service descriptions, and messages
3. a communications agreement centered around service descriptions based on WSDL
4. a messaging framework comprised of SOAP technology and concepts
5. a service description registration and discovery architecture sometimes realized through UDDI
6. a well-defined architecture that supports messaging patterns and compositions a second generation of Web services extensions

Web service Roles:

Web service Roles are

i)                    Service Providers

ii)                  Service Requestors and

iii)                Service Intermediaries

Definition of service model:

The manner in which services are being utilized in the real world, though, has led to a classification based on the nature of the application logic they provide, as well as their business-related roles within the overall solution. These classifications are known as service models. Its types are

i)                    Business Services

ii)                  Utility Services and

iii)                Controller Services