Towards the Design and Implementation of the DAME prototype: OGSA Compliant Grid Services on the White Rose Grid

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Towards the Design and Implementation of the DAME
prototypeOGSA Compliant Grid Services on the
White Rose Grid

• Sarfraz A Nadeem
• University of Leeds

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An Overview

• Distributed Aircraft Maintenance Environment
• White Rose Grid v/s Virtual Organisation
• OGSA compliant Grid Services
• Grid Services on the White Rose Grid
• XTO analysis tool
• XtoAnalysis Grid Service
• Plotting Charts

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DAME Distributed Aircraft Maintenance Environment

• Pilot project funded by the UK e-Science core
  program
• Aims at research, business and contribution
  towards Grid technologies
• To facilitate the diagnostic and maintenance of
  an aircraft engine in a distributed fashion
• To reduce the cost of an unexpected and unplanned
  maintenance of an aircraft engine

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WRG White Rose Grid

• A Virtual Organisation (VO)
• Transparent access to Grid resources
• No worries about physical location of resources
• Interested only in attributes and availability
• WRG is a practical example of VO
• Comprises high performance resources
• Resources are diverse in nature
• Subject to local administration, access control
  and security policies

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OGSA Compliant Grid Service Factory Approach

• A Factory Service is a secure and stateless
  persistent service
• Knows how to create instance(s) of transient,
  possibly stateful service
• Grid Service Handle (GSH) is just a URI that
  points to a Grid Factory Service
• Clients contact Factory Service and request to
  instantiate the service instance
• Factory Service returns Grid Service Reference
• If SOAP binding is used, GSR is just a WSDL
  document
• GSR / WSDL document explains Grid Service
  information such as available methods and message
  types

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XTO Grid Factory Services on the WRG

• XtoQuery Grid Service is designed to retrieve
  information from a MySQL database against input
  parameters
• XtoAnalysis Grid Service analyses aircraft engine
  data and uses gsiftp for
• Transfer of XTO analysis tool
• Transfer of ZMOD/binary data
• Transfer of XTO output data
• XtoChart Grid Service plots chart using XTO
  output data and uses GridFTP for
• Transfer of XTO output data
• Transfer of plotted chart in PNG/JPG format

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XTO Analysis Tool

• XTO is a framework
• Plug-ins perform the analysis job
• Plug-ins are specialised piece of software
• Four plug-ins are in use with current version
• 20 tracks / features are extracted
• 2 by the framework
• 18 by the plug-ins
• Fractional (3)
• Multiple (11)
• Residual energy (1)
• Step change (3)

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XtoAnalysis Grid Service (1)

• Two file are created during the transfer of XTO
  analysis tool to compute resource
• XTO configuration file
• XTO feature detector summary file
• This relies on
• A shell script
• User defined variables
• Variables define in Globus
• An RSL script

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XtoAnalysis Grid Service (2)

• RSL provides a common interchange language to
  describe resources
• User defined variables are used to construct an
  RSL script dynamically
• This RSL script outlines the job request
• Job request is parsed and processed by GRAM
• GASS server is used to run this scripted job

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XtoChart Grid Service Plotting Charts

• XtoChart Grid Service plots chats
• From XTO output data
• Using a public domain package customised to
  handle XTO output data
• GridFTP is an optimised, high-performance,
  secure, reliable data transfer protocol
• Used to transfer
• XTO output/XtoChart input data to Grid Service
  hosting machine
• Chart image from Grid Service hosting machine

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