dragonfly topology for networks presented by ： long bao
TRANSCRIPT
Dragonfly Topology for networks
Presented by： Long Bao
Netwrok
Topology
Topology
A
B
Topology
A1
B
A2A3
Topology
A
B
Perfect?
Topology
• Bandwidth• Latency• Cost• Scalability
Outlet
• Dragonfly Topology Description
• Dragonfly Topology Routing
• Cost analysis
• Conclusion
Dragonfly Topology Description
• Hierarchical Network– Router, Group and System
Figure 1. High-level block diagram of a dragonfly topology
Dragonfly Topology Description
• (a, p, h) network
• K=p+a+h-1• K’=a(p+h)• K’>>K• N=ap(ah+1)
Router 0 Router 1 Router a-1...
I0, I1,…, Ip-1 Ip, I1+p,…, I2p-1 Ik1-p, I1+k1-p,…, Ik1
O0, O1,…, Oh-1 Oh, O1+h,…, O2h-1 Ok1-h, O1+k1-h,…, Ok1
Inter-Group Interconnection
Network
Dragonfly Topology Description
• A simple example—(4,2,2) Network
R0 R1 R2 R3
R0
R1
R2
R3
R0
R1
R2
R3
R0
R1
R2
R3 R 0
R 1R 2
R 3
R0
R1
R2
R3
R0R1
R2R3
R0
R1
R2
R3
R0 R1 R2 R3
R0
R1
R2
R3
Dragonfly Topology Description
• Topology Variations
R0 R1 R2 R3
2 2
R0 R1 R2 R3 R4 R5 R6 R7
Dragonfly Topology Routing
• Existing routing algorithm– Minimal (Min)– Valiant (Max)– Universal Globally-Adaptive Load-balanced (UGAL)• UGAL-L• UGAL-G
Dragonfly Topology Routing
• Minimal and Valiant method
R0 R1 R2 R3 R0 R1 R2 R3
R0 R1 R2 R3
2 31
12
3
4 5
Non-mininal route
mininal route
Dragonfly Topology Routing
• UGAL– Problems• Limited throughput
R0 R1 R2 R3
I0, I1 I2, I3 I4, I5 I7, I8
O0, O1 O2, O3 O4, O5 O7, O8
R0 R1 R2 R3 R0 R1 R2 R3
Group 0 Group 1
Group 2
Non-mininal route
mininal route
Dragonfly Topology Routing
• UGAL– Problems• High intermediate latency
R0 R1 R2 R3 R0 R1 R2 R3
R0 R1 R2 R3
Q0
Q1 Q3Q2
Group 0
Group 2
Group 1
Cost analysis
• (15+15)/(15+15+15+15)=50%• 16/(16+15+15+15)=25%
Router
15
Dimension 3 channels Dimension 2
channels
Dimension 1 channels
Flattened Butterfly
Router
15
Inter-group channels
Inter-group channels
Dragonfly
1515 15 16 30
Global Local
Conclusion
• Less diameter• Low cost• Small latency
Future Work• Routing Strategy Research• High-radix topology