1 egoist overlay routing using selfish neighbor selection georgios smaragdakis joint work with...
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EGOIST Overlay Routing using Selfish Neighbor SelectionGeorgios Smaragdakis
Joint work with Vassilis Lekakis, Nikos Laoutaris, Azer Bestavros, John Byers and Mema Roussopoulos
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Overlay Networks
Applications Overlay routing P2P file sharing Content distribution networks Multimedia streaming Online multiplayer games ….
OverlayPlane
Physical Plane
O1
O2
O3
R4
R2
R7
R5 R6
R3R1
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Connectivity Management
Full mesh architectures for reliability(e.g. RON)
Myopic heuristicsrandom or proximity based neighbor selection
Tree forest or mesh construction to optimize multicast(e.g. Bullet, Splitstream)
Optimization for network delay(e.g. Detour, QRON)
Opportunistic choke/unchoke(e.g. BitTorrent)
Distributed hashing tables(e.g. Chord, Pastry, Tapestry)
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Selfish Neighbor Selection
[Laoutaris, Smaragdakis, Bestavros, Byers, INFOCOM’07]
Optimal wiring for vi: choose k neighbors, s.t.
viu
w
ij Vv
jiSiji vvdpC ),(min
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Selfish Neighbor Selection
The selfish node can reap substantial performance. The performance gain is higher under uninformed
overlays. The evolving stable graphs that consist of selfish nodes
are highly optimized.
Advantages
The computation of the exact optimal wiring might be expensive.
Requires full information about the network. The number of iterative wirings before stabilization might
be high.
Disadvantages
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EGOIST:Key Contributions
System Architecture
Link state protocol to support connectivity information dissemination.
Overlay monitoring and maintenance mechanism. Computationally efficient neighbor selection.
Performance Evaluation
Average performance in real operational scenaria. Performance under different performance metrics (delay,
system load, available bandwidth) Overhead of the implementation. Performance under churn. Vulnerability to malicious users. Applications.
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EGOIST:Basic Architecture
111.1.1.1
122.2.2.2
133.3.3.3
144.4.4.4
111.1.1.1 122.2.2.2 25msecs
111.1.1.1 133.3.3.3 165msecs
111.1.1.1 122.2.2.2 25msecs
111.1.1.1 133.3.3.3 165msecs
111.1.1.1 122.2.2.2 25msecs
111.1.1.1 133.3.3.3 165msecs
111.1.1.1 122.2.2.2 25msecs
111.1.1.1 133.3.3.3 165msecs
111.1.1.1 122.2.2.2 25msecs
111.1.1.1 133.3.3.3 165msecs
111.1.1.1 122.2.2.2 25msecs
111.1.1.1 133.3.3.3 165msecs
111.1.1.1 122.2.2.2 25msecs
111.1.1.1 133.3.3.3 165msecs
111.1.1.1 122.2.2.2 25msecs
111.1.1.1 133.3.3.3 165msecs
X
Objectives
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Performance Evaluation:Experimental Setting
Nodes: 50 PlanetLab nodes for 2
months.
Wiring policies: EGOIST k-Random, k-Closest, k-
Regular (DHT). Wiring frequency: 60
seconds.
Metrics of interest: Delay (ping, Pyxida). CPU load (loadavg). Available Bandwidth
(pathChirp).
Control variables: We vary the number (k) of
neighbors.
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7
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Performance Evaluation:Re-wiring Frequency
EGOIST wiring Approximate EGOIST wiring (e= 10%)
CPU, memory and bandwidth consumption is minimal.
EGOIST delay/optimal delayEGOIST re-wirings
Appr. EGOIST/optimal delayAppr. EGOIST re-wirings
Norm
aliz
ed
dela
y
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Performance Under Churn
Effi
ciency
Index
Connect
ivit
y
qualit
y
EGOIST
K-RandomK-RegularK-Closest
Hybrid-EGOIST
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Performance Under Churn
Effi
ciency
Index
Connect
ivit
y
qualit
y
EGOIST
K-RandomK-RegularK-Closest
Hybrid-EGOIST
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Performance Under CheatingD
ela
y/
Dela
y w
ith a
buse
truthfulEGOIST
truthfulEGOIST
UntruthfulTruthful
UntruthfulTruthful
Many Untruthful nodesSingle Untruthful node
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Applications
Multi-path file transfer
Real-time VoIP
Online multiplayer P2P games
[Quake III traces from Donnybrook, SIGCOMM’08]
EGOISTk-Closest
k-Randomk-Regular
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Current Status
Explore worst case scenaria for cheating.
Study scalability.
Provide a general wiring service.