Soumadri Roy ChowdhuryAssociate ID: 68313

Web Services

Introduction to

Agenda

The Past1

The Present2

The Future (definitely it’s Web Services )3

A peep into the future4

The Past

Client Server Architecture

Problems it faced:

1. Scalability2. Single point failure

The Present

3-tier Architecture What it uses

• DCOM (Distributed Component Object Model)• RMI (Remote Method Invocation)• CORBA (Common Object Request Broker

Architecture)

Problems it faced:– Interoperability– Tight coupling– Crossing firewall

Get ready for the future…

Web + Services Web – The facilities are provided via World

Wide Web. Services – Facilities provided to you by

some provider.

A classic exampleCourier Delivery system

“I wanted this parcel to reach on time. I don’t bother how your delivery system works.”

“I don’t bother that you are late because the delivery van was stuck in some problem.”

Encapsulation

Loose Coupling

The Future

Web Services Solution to earlier problems

• Encapsulation• Loose coupling• Contract based architecture

A formal definition• “Web Services are encapsulated, loosely

coupled contracted Service Provider functions offered via standard protocols”

- WebServices.org

A peep into the future…Architecture

A peep into the future…

SOAP (Simple Object Access Protocol)

Web Services

WSDL(Web Services Definition Language)

UDDI(Universal Discovery Description Integration)

Protocols used

A peep into the future…Protocols

SOAP Used to exchange messages between

Service Requester, Service Broker and Service Provider

SOAP contd…

A peep into the future…Protocols WSDL

WSDL describes network services by using an XML grammar

A peep into the future…Protocols UDDI

It represents the service broker that enables service requesters to find a suitable service provider

…

Architecture + Protocols

A friendly note…

KISS

Keep It Simple, Stupid!

“Keep it simple. When in doubt during design, choose the simplest solution.”

-Brian Carpenter , Internet Architecture Board

“The Question” Award