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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.