Wireless Data Center Network. Reporter: Green

Transcription

1 Wireless Data Center Network Reporter: Green

2 Outline What is DCN? Challenges in current DCN Cable Topology Traffic load Heterogeneous DCN Optical DCN Wireless DCN Challenges in WCDN The researches in WDCN 2

3 What is DCN? day3.cloud.infrastructure.aspx 3

6 What is DCN? Cui. Y, Wang, H. Cheng, X. Chen, B. Wireless data center networking, Wireless Comm., IEEE,

7 What is DCN? 7

8 What is DCN? Data Center Requirements High inter-node link capacity Bandwidth-demanding operations: E.g., GFS Distributed processing of large amounts of data: E.g., MapReduce Reliability Provision sources to meet the requirements of DCN Security Isolation Data exchanged between services in DCN must be isolated Scalability Link connectivity should scale to support large numbers of machines Small form factor of networking components: Higher processing requirements Floor space constraints Reduced energy consumption K. Ramachandran et al. 60 GHz data-center networking: Wireless=>worry less?, Technical report, NEC,

9 Challenges in Current DCN By the year of 2014 Google has got over servers in its 30 data centers For traditional schemes Expensive high-end switches and a large number of wires Facts and Stats of World s largest data centers Yong Cui, Hongyi Wang, Xiuzhen Cheng, Channel Allocation in Wireless Data Center Networks, INFOCOM,

10 Challenges in Current DCN High maintenance challenges Cabling complexity Cables take up space Hard to keep accurate per-cable info Inefficient cooling Under raised floors Airflow blockages Substantial operational costs 7-8% of the total infrastructure cost K. Ramachandran et al. 60 GHz data-center networking: Wireless=>worry less?, Technical report, NEC,

11 Challenges in Current DCN K. Ramachandran et al. 60 GHz data-center networking: Wireless=>worry less?, Technical report, NEC,

12 Challenges in Current DCN OO(nn) OO(nn 2 ) Katayama, Y. ; Takano, K. ; Kohda, Y. ; Ohba, N. ; Nakano, D., Wireless data center networking with steered-beam mm wave links, WCNC,

13 Challenges in Current DCN S. Kandula, J. Padhye, and P. Bahl. Flyways to de-congest data center networks. In HotNets, Nov

14 Challenges in Current DCN S. Kandula, J. Padhye, and P. Bahl. Flyways to de-congest data center networks. In HotNets, Nov relieve hotspot and boost performance 14

15 Challenges in Current DCN D. Halperin, S. Kandula, J. Padhye, P. Bahl, and D. Wetherall, Augmenting Data Center Networks with Multi-Gigabit Wireless Links, SIGCOMM,

16 Heterogeneous DCN G. Wang, David G. Andersen, Michael K, Konstantina Papagiannaki, T.S. Eugene Ng, Michael Kozuch, Michael Ryan, c-through: part-time optics in data centers, SIGCOMM,

17 Heterogeneous DCN 17 Farrington, N., et al. Helios: A hybrid lectrical/optical switch architecture for modular data centers. In Proc. Of SIGCOMM (2010).

18 Heterogeneous DCN Katayama, Y. ; Takano, K. ; Kohda, Y. ; Ohba, N. ; Nakano, D., Wireless data center networking with steered-beam mm wave links, WCNC,

19 Heterogeneous DCN Cui. Y, Wang, H. Cheng, X. Chen, B. Wireless data center networking, Wireless Comm., IEEE,

20 The Researches in WDCN The technologies used in WDCN c ad 20

21 Introduction of Wireless Technology 21

22 Introduction of Wireless Technology ad-60-ghz-technologies

23 The Researches in WDCN D. Halperin, S. Kandula, J. Padhye, P. Bahl, and D. Wetherall, Augmenting Data Center Networks with Multi-Gigabit Wireless Links, SIGCOMM,

24 The Researches in WDCN S. Kandula, J. Padhye, and P. Bahl. Flyways to de-congest data center networks. In HotNets, Nov relieve hotspot and boost performance 24

25 Introduction -WDCN Hardware Design WDCN Resource Allocation 25

26 Hardware Design The Researches in WDCN [1] K. Ramachandran et al. 60 GHz data-center networking: Wireless=>worry less?, Technical report, NEC, ( 凱旭 ) [2] S. Kandula, J. Padhye, and P. Bahl. Flyways to de-congest data center networks. In HotNets, Nov relieve hotspot and boost performance ( 凱旭 ) [3] Vardhan, H. ; Thomas, N. ; Seong-Ryong Ryu ; Banerjee, B. ;Prakash, R., Wireless Data Center with Millimeter Wave Network, GLOBECOM, 2010 [4] D. Halperin, S. Kandula, J. Padhye, P. Bahl, and D. Wetherall, Augmenting Data Center Networks with Multi-Gigabit Wireless Links, SIGCOMM, 2011( 于翔 ) [5] Katayama, Y. ; Takano, K. ; Kohda, Y. ; Ohba, N. ; Nakano, D., Wireless data center networking with steered-beam mm wave links, WCNC, 2011 [6] W. Zhang, X. Zhou, L. Yang, Z. Zhang, B. Y. Zhao, and H. Zheng. 3D Beamforming for Wireless Data Centers. HotNets, 2011 ( 凱程 ) [7] Yamane. T., katayama. K., An effective initialization of interference cancellation algorithms for distributed MIMO systems in wireless datacenters, GLOBECOM, 2012 [8] Katayama, Y. ; Yamane, T. ; Kohda, Y. ; Takano, K. ;Nakano, D. ; Ohba, N. MIMO link design strategy for wireless data center applications, WCNC, 2012 [9] Xia Z., Zengbin Z., Yibo Z., Yubo Li, Saipriya Kumar,. Amin Vahdat, Ben Y., Mirror Mirror on the Ceiling: Flexible Wireless Links for Data Centers, SIGCOMM, 2012 ( 凱程 ) [10] Shin, J.-Y. ; Sirer, E.G. ; Weatherspoon, H. ; Kirovski, D., On the Feasibility of Completely Wireless Datacenters, Networking, IEEE/ACM Transactions on, vol. PP, no. 99,

27 Resource Allocation The Researches in WDCN [1] Cui. Y, Wang, H. Cheng, X. Chen, B. Wireless data center networking, Wireless Comm., IEEE, 2011 ( 專題生 ) [2] Cui. Y, Wang, H. Cheng, X., Wireless Link Scheduling for Data Center Networks, ICUIMC, 2011( 凱程 ) [3] Cui. Y, Wang, H. Cheng, X., Channel allocation in wireless data center network, INFOCOM, 2011 [4] Cui. Y, Wang, H. Cheng, X., Li, D. Ylä-Jääski, A., Dynamic Scheduling for Wireless Data Center Networks, Parallel and Distributed Systems, IEEE Transactions on, vol. PP, no. 99, 2013 ( 凱旭 ) Scheduling by traffic load: - The heuristic algorithm (by distance) - Min-Max Scheduling (by distance) - Genetic Algorithm (by interference && transmitting speed) The data traffic in ToR switches is heavy and may cause serious degradation in network performance 27

28 The Researches in WDCN At Microsoft Research in Redmond, Wash., 60 GHz wireless links are atop server racks. The links are intended to speed data flow at crunch times. 28

29 Suitability of 60 GHz radios Spectrum availability License-free 60 GHz range (57-64 GHz) 70 orthogonal channels 1GHz = 10 channels (100MHz per channel) Improved interference mitigation and security Path loss attenuation due to low frequency Highly directional beams with small footprints Small λ and more # of antennas in a phased array LLLLLLLL wwwwwwwwww = LLLLLLLL wwwwwwwwwwwwwwww (less than 15 ) Scalability Scale DCN connectivity Small form-factors E.g., UWB (3.1 to 10.6GHz) requires 30cm x 30cm form factor Universal operation License-free in many countries K. Ramachandran et al. 60 GHz data-center networking: Wireless=>worry less?, Technical report, NEC,

30 The Researches in WDCN Vardhan, H. ; Thomas, N. ; Seong-Ryong Ryu ; Banerjee, B. ;Prakash, R., Wireless Data Center with Millimeter Wave Network, GLOBECOM,

31 Challenges of 60 GHz radios Characters of 60 GHz Travel shorter distances Suffer significant attenuation from obstacles Small λ Challenges of 60 GHz Lower bandwidth in practice Lower reliability High propagation loss and attenuation One of solution: High transmit powers, but power consumption K. Ramachandran et al. 60 GHz data-center networking: Wireless=>worry less?, Technical report, NEC,

32 Challenges in WDCN How to determine the best beam to communicate with? TX Use feedback channel info to formbeams off-line Use a table-lookup at runtime RX Estimate the channel from TX Feedback channel info to TX How often to carry out channel measurements? For beam forming Use the same beam in TX and RX? Need a suitable algorithm in DCN Map receiver feedback to antenna patterns? Dynamic channel fluctuations People walking within in DCN K. Ramachandran et al. 60 GHz data-center networking: Wireless=>worry less?, Technical report, NEC,

33 Challenges in WDCN Yamane. T., katayama. K., An effective initialization of interference cancellation algorithms for distributed MIMO systems in wireless datacenters, GLOBECOM,

34 Wireless Data Center Katayama, Y.,Yamane, T., Kohda, Y., Takano, K., Nakano, D., Ohba,N., MIMO link design strategy for wireless data center applications, WCNC,

35 Wireless Data Center D. Halperin, S. Kandula, J. Padhye, P. Bahl, and D. Wetherall, Augmenting Data Center Networks with Multi-Gigabit Wireless Links, SIGCOMM,

36 Wireless Data Center K. Ramachandran et al. 60 GHz data-center networking: Wireless=>worry less?, Technical report, NEC,

37 Challenges in WDCN How to compute multi-hop routes? By two arbitrary nodes that cannot be directly connected How to handle node and link failures? How to choose the optimal path Distribute the traffic for load balancing? Do nodes need to maintain multiple paths TXs deal with small time-scale channel fluctuations? How much do reflectors help improve link reliability? Is there an optimal placement of reflectors Max. performance && min. # of used reflectors 37

38 The Reaserches in WDCN Vardhan, H. ; Thomas, N. ; Seong-Ryong Ryu ; Banerjee, B. ;Prakash, R., Wireless Data Center with Millimeter Wave Network, GLOBECOM,

39 The Researches in WDCN Xia Z., Zengbin Z., Yibo Z., Yubo Li, Saipriya Kumar,. Amin Vahdat, Ben Y., Mirror Mirror on the Ceiling: Flexible Wireless Links for Data Centers, SIGCOMM,

43 The Researches in WDCN Shin, J.-Y. ; Sirer, E.G. ; Weatherspoon, H. ; Kirovski, D., On the Feasibility of Completely Wireless Datacenters, Networking, IEEE/ACM Transactions on, vol. PP, no. 99,

44 The Researches in WDCN Shin, J.-Y. ; Sirer, E.G. ; Weatherspoon, H. ; Kirovski, D., On the Feasibility of Completely Wireless Datacenters, Networking, IEEE/ACM Transactions on, vol. PP, no. 99,

45 The Researches in WDCN For redundancy elimination 45