Some Basics of Globus Web Services Adarsh Patil http://www.adarshpatil.com/

GGF-Globus Grid Forum  GGF4 was formed on Feb 2002  Globus team and IBM proposed first OGSA specification to merge Globus and Web Services (globus 2.x to globus 3.x)  This is a body for designing standards for the Grid.

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OGSI-Open Grid Service Implementation 

It is an technical specification for the implementation of Grid Services as described in the OGSA specification

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Globus Toolkit 3 and 4 are OGSA complaint and are Service Oriented Grid Systems

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Grid services are transient and stateful. Due to heavy specifications in one and only OGSI (too many specification in OGSI) it does not fit in web services and xml protocols

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WSRF-Web Service Resource Framework 

Globus Alliance + IBM + HP --> introduced WSRF to solve this issue ( many implementations in specification of OGSI)

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WSRF standard promises this effort

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Web Services 

Based on Service Oriented Architecture

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Clients are service Requestors

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Servers are service Providers

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XML, http, SOAP, WSDL, UDDI, WS Inspection language are used

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Request, Publish, Registry

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WSDL-Web Service Description Language 

It’s a XML based specification

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It is used to describe Web Service

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It describes

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What a service can do?

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Where is its location?

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How to invoke it ?

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SOAP-Simple Object Access Protocol 

It’s a communication protocol for clients and servers to exchange messages in XML format over http

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It specifies rules, header, body(URI)

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The message contains

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SOAP envelope

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SOAP schema

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XML schema definition

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UDDI Universal Description, Discovery, and Integration 

Service discovery and registration

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Used to advertise services

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Used to find appropriate services

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Use to publish/obtain services

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Provider, User, Registry - white pages, yellow pages , green pages

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OGSA- Open Grid Service Architecture 

Architecture to build service oriented Grid.

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It is based on web services

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It uses protocols such as xml, http

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Concept of Grid Services was introduced in OGSA

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It defines various aspect of Grid Service and interfaces that are needed.

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OGSA-WG is the work group which works on the design of OGSA specification

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Credits/Acknowledgements 

http://www.globus.org

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http://www.globusconsortium.com/

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http://www.globusworld.org/

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http://www.ggf.org/

Text Books

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The Grid 2: Blueprint for a New Computing Infrastructure (The Morgan Kaufmann Series in Computer Architecture and Design)

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The Grid : Core Technologies

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Grid Computing: Making The Global Infrastructure a Reality