Protecting Application Developers – A Client Toolkit for OGSA-DAI

Alastair Hume (A.Hume@epcc.ed.ac.uk)

Tom Sugden, Mike Jackson, Mario Antonioletti, Neil Chue Hong, Amy Krause and Martin Westhead

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OGSA-DAI Client Toolkit

A high-level API for writing client-side interactions with OGSA-DAI services

Aims: Provide a clear and simple API built around

solid abstractions Minimise specialist knowledge and the

number of steps required to achieve results Protect to the application developer from

future changes to the OGSA-DAI interfaces

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Solid Abstractions

Registry Grid Data Service Factory Grid Data Service Request

Constructed from Activities Response

Easily converted to appropriate types, e.g. ResultSet or ResourceSet.

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Minimise Specialist Knowledge

Client Toolkit JDBC XMLDB

AxisGlobusToolkit

DOMXerces

OGSA-DAI Services

Higher-levelAPIs

Lower-levelAPIsClient

Machine

ServiceContainer

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Minimise the Number of Steps

0

20

40

60

80

lines of code import statements

using client toolkit w ithout client toolkit

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Protection From Future Changes

Proposed Web and Grid standards in state of flux

Changes to standards cause changes to the OGSA-DAI interface

Especially OGSI->WS-RF and DAIS Client toolkit will hide a lot of these

changes from the application developer Client toolkit makes OGSA-DAI a more

stable solution in these times of constant change

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Future for Client Toolkit Data Resource concept may replace the

GDSF and GDS Loosens coupling between client toolkit

and service architecture Will work with all future supported OGSA-

DAI interfaces – OGSI, WS-RF, WS-I Automatically switch to the appropriate

interface for the service? Depreciation policy Standardisation across all OMII products

at client toolkit level?