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Optimal Resource Placement in Structured Peer-to-Peer NetworksAuthors: W. Rao, L. Chen, A.W.-C. Fu, G. Wang Source: IEEE Transactions on Parallel and Distributed Systems, vol. 21, no. 7, pp. 1011-1026, 2010Speaker: Huan-Chin Hsu (徐煥欽 )Date: 2010/10/08
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Outline
• Introduction– Chord– Symphony– Problems
• Proposed scheme– Resource placement strategy– PCache– PRing
• Experimental results• Conclusions• Comments
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Chord
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SymphonyN1
N8
N14
N21
N32
N38
N42
N48
N51
N56
K54
Short links
Long links
Lookup path
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Problems
• Skewed Popularity – Popular objects create excessive
workload– Overloading problem
• Where to place the resources?• How many resources are needed?
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Resource placement strategy
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Placement strategy in symphony
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PCache architecture
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PCache• Load Balancing• Popularity Estimation
– Aggregation protocol
• Consistency Maintenance– Object version
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PRing in Symphony
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Experimental results(1/4)• Solving MAX_PERF Problem with N = 4000 to Evaluate the
Achieved Average Lookup Hops H
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Experimental results(2/4)• Solving MIN_COST Problem with N = 4000 to Find the Consumed
Replicas (×1000)
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Experimental results(3/4)
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Experimental results(4/4)
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Conclusions
• Propose a resource allocation solution PCache which can optimally trade off the performance gain and paid cost.
• And the optimal ring structure, PRing with better results than existing works.
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Comments• Web object version problem in PCache.• PRing still skewed popularity.• PCache not suitable for use in large siz
e files.