UNIVERSITY OF JYVÄSKYLÄ
Topology Management Algorithmsin Chedar InBCT 3.2 Peer-to-Peer communicationCheese Factory -projecthttp://tisu.it.jyu.fi/cheesefactory
Research AssistantAnnemari Auvinen
University of Jyväskylä
Agora [email protected]
2004
UNIVERSITY OF JYVÄSKYLÄ
Hit values
• Active connections and history data contains– Hit values:
• Increased every time the node gets reply to resource query from the connection
– Relayed hits• Connection measures how many replies its neighbors
have relayed
2004
UNIVERSITY OF JYVÄSKYLÄ
Overtaking 1/2
• Peer moves closer to the ”good” peers• Overtaking percent• If connection has neighbor which relayed hits
proportion of all neighbors relayed hits and connection’s hits is more than the given percent a new connection to that neighbor is established and current connection is dropt
1 23
4Hits:2
Relayed hits:6 (60%)
Relayed hits:2 (20%)
1 23
4
2004
UNIVERSITY OF JYVÄSKYLÄ
Overtaking 2/2
• Peers which provide lots of good resources are in the middle of the network
• Power-law network: a few nodes with many neighbors and a lot of nodes with a few neighbors -> fault tolerant and efficient topology for searching
2004
UNIVERSITY OF JYVÄSKYLÄ
Node Selection
1. Tries to establish the connections which the peer had before leaving the network
2. History data1. Connections with hit values and ”old” request
time
2. Connections with ”old” request time or unrequested connections
2004
UNIVERSITY OF JYVÄSKYLÄ
Node Removal
• Selects the ”worst” connection • Worst connection is a connection which has
the lowest goodness value• Goodness value:
– Connection’s hits + its neighbors’ relayed hits
2004
UNIVERSITY OF JYVÄSKYLÄ
Load estimation
• Connections are established and dropped based on the traffic amount flowing through the node
• ConnectionManager measures the traffic in the given time sequence and if it is more than the given traffic limit one connection is dropped by using Node Removal
• If the traffic meter is less than the limit, algorithm tries to establish a new connection by using Node Selection
1 2
3
1 2
3
UNIVERSITY OF JYVÄSKYLÄ
Results
2004
UNIVERSITY OF JYVÄSKYLÄ
Overtaking 20%
Naapureiden jakauma
0
2
4
6
8
10
12
14
16
1 2 3 4 5 6 7 8 9 10 11
Naapureiden lukumäärä
So
lmu
jen
luk
um
ää
rä
Ohitus 20% Potenssijakauma
2004
UNIVERSITY OF JYVÄSKYLÄ
Overtaking 20%
Suurimman solmun kehitys ohitusprosentilla 20
0
5
10
15
20
25
010
020
030
040
050
060
070
080
090
010
0011
0012
00
Lähetetyt viestit
Na
ap
ure
ide
n lu
ku
mä
ärä
Ensimmäinen testi Toinen testi
2004
UNIVERSITY OF JYVÄSKYLÄ
Overtaking 80%
Naapureiden jakauma
0
2
4
6
8
10
12
1 2 3 4 5 6 7 8 9 10
Naapureiden lukumäärä
So
lmu
jen
luk
um
ää
rä
Ohitus 80% Potenssijakauma
2004
UNIVERSITY OF JYVÄSKYLÄ
Overtaking 80%
Suurimman solmun kehitys ohitusprosentilla 80
0
2
4
6
8
10
12
010
020
030
040
050
060
070
080
090
010
0011
0012
00
Lähetetyt viestit
Na
ap
ure
ide
n lu
ku
mä
ärä
Ensimmäinen testi Toinen testi Kolmas testi
2004
UNIVERSITY OF JYVÄSKYLÄ
Overtaking
• Overtaking percent 20% + gives power-law network+ the biggest nodes provides a lot of resources- network doesn’t converge -> creating and dropping
connections creates traffics and loads the network
- Overtaking percent 80%+ network converges+ the biggest nodes provides a lot of resources- not power-law distributed network but some
features of it
2004
UNIVERSITY OF JYVÄSKYLÄ
Load Estimation
• Traffic limit 60kB
Naapureiden jakauma
0
5
10
15
20
25
3 4 5 6 7 8
Naapureiden lukumäärä
So
lmu
jen
luk
um
ää
rä
Kuormituksen yläraja 60 kB Normaalijakauma
2004
UNIVERSITY OF JYVÄSKYLÄ
Load Estimation
Suurimman solmun kehitys
0
2
4
6
8
10
12
14
010
020
030
040
050
060
070
080
090
010
0011
0012
00
Lähetetyt viestit
Na
ap
ure
ide
n lu
ku
mä
ärä
Kuormitus 60kB
2004
UNIVERSITY OF JYVÄSKYLÄ
Interaction of Overtaking and Load Estimation
• Overtaking 80% and traffic limit 60kB
Naapureiden jakauma
02468
1012141618
5 6 7 8 9 10
Naapureiden lukumäärä
So
lmu
jen
luk
um
ää
rä
Ohitus 80% ja kuormituksen yläraja 60 kBPotenssijakaumaNormaalijakauma
2004
UNIVERSITY OF JYVÄSKYLÄ
Interaction of Overtaking and Load Estimation
Suurimman solmun kehitys
0
2
4
6
8
10
12
14
010
020
030
040
050
060
070
080
090
010
0011
0012
00
Lähetetyt viestit
Na
ap
ure
ide
n lu
ku
mä
ärä
Ohitusprosentti 80 ja kuormitus 60kB
2004
UNIVERSITY OF JYVÄSKYLÄ
Future
• Testing in simulator with information about reply messages hops
• Peer’s goodness in relation to sent resource queries
• Topology management using a neural network for making Chedar adaptive in wide range of peer-to-peer networks