Performance Evaluation of a SNAP-based Community Resource Broker

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Performance Evaluation of a SNAP-based Community
Resource Broker
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Outline

• DAME Project (Distributed Aircraft
• Maintenance Environment)

• Current challenges within Grid middleware

• Grid Resource Brokers

• Service Negotiation Acquisition Protocol

• Use of a Knowledge bank

• Three-phase Commit protocol

• Performance results

• Conclusion and future work

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DAME Project (Distributed Aircraft Maintenance
Environment)

• DAME is a joint project
• Four Universities, Leeds, York,
• Sheffield and Oxford
• Industrial partners are Rolls Royce,
• Data Systems and Solutions and Cybula Ltd

• This project aims to build a distributed
  diagnostics
• decision support system, for the use of
  Virtual
• Organisations (VOs), based on Grid
• technology

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Current Challenges within Grid Middleware
There are many complexities in-order to submit a
simple Grid job

• Have the ability to query local and remote
  resource
• Information Providers
• Identify and filter out the appropriate
  resources
• for the job
• Co-allocate the job
• Secure the resources
• Submit the job
• Monitor and police the active job

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Grid Resource Brokers

• A Resource Broker is a middleware entity that
• insulates the user from the Grid
  complexities
• Two broad categories of resource brokers
• System-centric which enhances system utilisation
  and throughput
• User-centric which enhances computation and
  adheres to user requirements

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Service Negotiation and Acquisition
Protocol (SNAP)
Task Service Level Agreement (TSLA).
Resource Service Level Agreement (RSAL).
Binding service level agreement (BSLA).
QoS needs
TSLA
Policies
User requirements through a Grid portal
Feedback on decisions made
Observation
Resource broker
Resource query/ Dispatch
RSLA
Active Job
SLA
Resources
Resource availability
Monitor
Policing
Resources
BSLA
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SNAP Development
TSLA
Portal
Knowledge bank
Matchmaker
Co-ordinator
RSLA
Dispatcher
BSLA
Grid middleware
Resources
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Knowledge Bank (KB)
Benefits of having a KB

• Enhance efficiency by avoiding unnecessary
• interaction with resources

• Alleviate the user from the burden of keeping a
• log of the resources

• Facilitate the broker in supporting automated
• resource discovery

• The KB
• stores a history profile of past performance of
  resources
• enables the broker to differentiate and
  categorise the
• resources into different levels

• An analogy to the KB is a telephone directory

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Need to Secure Resources
TSLA
Portal
Knowledge bank
Matchmaker
Co-ordinator
RSLA
Dispatcher
BSLA
Grid middleware
Resources
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Three-Phase Commit Protocol

• First phase
• Contact the categorised resources which would
  either be tagged as white or blue

• Establish a socket connection for probing the
  dynamic information and
• keeping a vision of any resource status
  change

• Second phase
• On receiving the information from all the
  contacted resources, the broker co-allocates
• the task
• The selected resources are reserved and evolve
  into the amber state
• The data is transferred

• Third phase
• The information service updates the
• resource status to red and the job is bound
• to the resources and begins execution

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Experimental Design and Performance Evaluation

• Objectives
• Investigate behaviour of both a simple SNAP
  broker and one using the three-phase commit
  protocol
• Performance evaluation
• Scenario 1
• Resources appropriate for the job are taken and
  the broker must wait until they become free
  before submitting the job
• Case A
• The information provider response time varies
  but the job duration is
• constant
• Case B
• The information provider response time is
  constant but the job duration
• is varied
• Scenario 2
• While the broker is in the process of making a
  decision as to where the job should be submitted
  the resources are taken

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Results Scenario 1 Case A Experiment 1
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Results Scenario 1 Case A Experiment 2
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Results Scenario 1 Case B Experiment 1
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Results Scenario 1 Case B Experiment 2
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Results Scenario 2 Experiment
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Future Work
To deploy the SNAP-based resource broker on the
White Rose Grid (WRG) using the Three-phase
commit protocol.
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Conclusion

• SNAP-based resource broker is a viable contender
  for use in future Grid implementations.
• Results indicate that in certain specific
  scenarios, three-phase commit protocol provides a
  performance enhancement over a simple SNAP-based
  broker.
• Further work would be to investigate the broker
  in a wider scenario space through mathematical
  modelling and simulation and for it to be
  deployed on the WRG.

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References

• M.H. Haji, P.M. Dew, K. Djemame, I. Gourlay.
• A SNAP-based Community Resource Broker using
  a Three-Phase Commit
• Protocol, 18th IEEE International Parallel
  and Distributed Processing
• Symposium, Santa Fe, New Mexico, April 2004.
• 
  
• K. Djemame, M.H Haji, J. Padgett. SLA
  Management in a
• Service Oriented Architecture, 2004
  International Conference on
• Computational Science and its Application,
  Assisi, Italy , May 2004.
• A. Othman, P. Dew, K. Djemame, I. Gourlay
  Adaptive Grid Resource
• Brokering, IEEE Cluster Computing, December
  2003, Hong Kong.