Dragonfly+: Low Cost Topology for scaling Datacenters

1. Dragonfly+: Low Cost Topology for scaling Datacenters Authors: Alexander Shpiner, Zachy Haramaty, Saar Eliad, Vladimir Zdornov, Barak Gafni and Eitan Zahavi

2. Outline:

3. Topology Dragonfly Topology Fat Tree Topology

4. Topology Dragonfly+

5. Topology Dragonfly+

6. Topology Dragonfly+

7. Topology For keeping full bi-sectional bandwidth inside the group: (1) p= l = s = h (2) p= h = k/2 (3) Ngroup = pl = (k*k)/4 l: leaf routers p: hosts per leaf routers  s,h: spine routers k: router radix Ngroup : number of hosts in the group

8. Routing

9. Deadlock Avoidance (1) Packet that traverses the minimal route does not change its VL. (2) Packet that traverses the intermediate spine route changes its VL in intermediate spine router. (3) Packet that traverses the intermediate leaf route changes its VL in intermediate leaf router.

10. Routing Is Min-routing optimal?

11. Routing Fully Progressive Adaptive Routing (FPAR-Rules)

12. Routing Fully Progressive Adaptive Routing(FPAR-Rules)

13. Routing How does it handle Remote Congestion? ARN(Adaptive Routing Notification)  ARN messages: destination address A and incoming port ARN ARN messages are sent among the routers to notify distant congestion that can be resolved by previous router on the route. Packet

14. Analytical and Simulative Analysis

15. Analytical Analysis Scalability Fig A. Maximal network size in number of hosts vs. Router radix (k). Fig B. Group size in number of hosts vs router radix(k).  Dragonfly+ and Non-blocking Fat Tree graphs are merging

16. Analytical Analysis

17. Simulative Analysis (over Omnet++ based infrastructure)

18. Simulative Analysis -Uniform Random Traffic Fig: End to End Network Latency vs. Load with Uniform Random Traffic

19. Simulative Analysis -Permutation Traffic Fig A: Speedup of Permutation Pattern with various routing schemes and message size Fig B: Mean End to End Network Latency vs. Load with Permutation Traffic with message size of 1MB.

20. Conclusions