Analysis of Peer to Peer Communication in Networks 2/15/10 - - PowerPoint PPT Presentation

Prestige Lecture Purdue University

Analysis of Peer to Peer Communication in Networks

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Outline of presentation

 Overview  Fluid analysis (after Massoulie and Vojnovic)  Direct stochastic analysis (work with Ji Zhu)  Discussion

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Prestige Lecture Purdue University

Traditional File Service

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Prestige Lecture Purdue University

Peer-to-peer File Service

Service capacity scales with demand ! Scalable Robust

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Prestige Lecture Purdue University

1st Generation P2P Systems

Entire file uploaded in

• ne shot

Users wait till entire file is received before relaying BUT if file size is large,

• 1. Long delay before users

become useful.

• 2. If users depart mid-way, a

lot of upload time wasted. e.g. Gnutella, KaZaa

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2nd Generation P2P Systems

Peers can start serving pieces without waiting for entire file. File split into pieces More effective at serving large files. e.g. BitTorrent, eDonkey

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Prestige Lecture Purdue University

Relative Popularity

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Prestige Lecture Purdue University

File Types in eDonkey

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Prestige Lecture Purdue University

Flash Crowds

Users requesting LoTR III on BitTorrent Flash Crowd: large number

• f users start requesting same

file simultaneously

Scenario where P2P system design tested most severely.

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Prestige Lecture Purdue University

Our Motivation

To understand second-generation peer-to-peer systems Peer selection strategies Piece selection strategies Push vs. pull Effects of heterogeneous link speeds Effects of network topologies ISP friendly operation Applications: file transfer, live streaming, video on demand,

• nline interactive gaming or instruction, . . .

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Prestige Lecture Purdue University

peers collecting pieces (coupons) seed initial seeding peers pieces

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Prestige Lecture Purdue University

peers collecting pieces (coupons) seed initial seeding peers pieces

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Prestige Lecture Purdue University

peers collecting pieces (coupons) seed initial seeding peers pieces

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Prestige Lecture Purdue University

peers collecting pieces (coupons) seed initial seeding peers pieces

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Prestige Lecture Purdue University

peers collecting pieces (coupons) initial seeding peers pieces

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Prestige Lecture Purdue University

peers collecting pieces (coupons) seed initial seeding peers pieces

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Prestige Lecture Purdue University 2/15/10

peers collecting pieces (coupons) seed

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Prestige Lecture Purdue University 2/15/10

peers collecting pieces (coupons) seed

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Prestige Lecture Purdue University 2/15/10

peers collecting pieces (coupons) seed

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Prestige Lecture Purdue University

• ne club

(members have all pieces except piece one) normal young peers peers pieces infected young peers seed

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Prestige Lecture Purdue University

• ne club

normal young peers infected young peers seed

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Prestige Lecture Purdue University 2/15/10

• ne club

normal young peers infected young peers seed

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• ne club

normal young peers infected young peers seed

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1 K-1 2 i 1 K-1 2 i j

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2/15/10 Prestige Lecture Purdue University

1 K-1 2 i 1 K-1 2 i j

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Discussion

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2/15/10 Prestige Lecture Purdue University

Discussion (continued)

• ne club

(members have all pieces except piece one) infected young peer normal young peer

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Discussion (continued)

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2/15/10 Prestige Lecture Purdue University

Discussion (continued)

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Thanks!

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