Publications

Journal Publications: 

·        Tao Wang, Fangming Liu*, Hong Xu, "An Efficient Online Algorithm for Dynamic SDN Controller Assignment in Data Center Networks", to appear in IEEE/ACM Transactions on Networking (TON), 2017.

·        Xiaomeng Yi, Fangming Liu*, Di Niu, Hai Jin, John C.S.Lui, "Cocoa: Dynamic Container-based Group Buying Strategies for Cloud Computing", to appear in ACM Transactions on Modeling and Performance Evaluation of Computing Systems (TOMPECS), Volume 2, Issue 2, May 2017.

·        Zhaojie Niu, Bingsheng He, and Fangming Liu, "JouleMR: Towards Cost-Effective and Green-Aware Data Processing Frameworks", to appear in IEEE Transactions on Big Data, 2017.

·        Fangming Liu, Jian Guo, Xiaomeng Huang, John Lui, "eBA: Efficient Bandwidth Guarantee under Traffic Variability in Datacenters", IEEE/ACM Transactions on Networking (TON), Vol. 25, No. 1, Feb., 2017.

·        Zhi Zhou, Fangming Liu*, Zongpeng Li, "Bilateral Electricity Trade Between Smart Grids and Green Datacenters: Pricing Models and Performance Evaluation", IEEE Journal on Selected Areas in Communications (JSAC), Series on Green Communications and Networking, Volume: 34, Issue: 12 Pages: 3993 - 4007, December 2016.

·        Zhi Zhou, Fangming Liu*, Ruolan Zou, Jiangchuan Liu, Hong Xu, Hai Jin, "Carbon-aware Online Control of Geo-Distributed Cloud Services", IEEE Transactions on Parallel and Distributed Systems, Volume 27, Issue 9, September 2016.

·        Jian Guo, Fangming Liu*, John Lui, Hai Jin, "Fair Network Bandwidth Allocation in IaaS Datacenters via a Cooperative Game Approach", IEEE/ACM Transactions on Networking (TON), Volume 24, Issue 2, April 2016.

·        Fangming Liu, Peng Shu, John Lui, "AppATP: An Energy Conserving Adaptive Mobile-Cloud Transmission Protocol", IEEE Transactions on Computers, vol. 64, no. 11, Nov. 2015.

·        Fei Xu, Fangming Liu*, Hai Jin, "Heterogeneity and Interference-Aware Virtual Machine Provisioning for Predictable Performance in the Cloud", IEEE Transactions on Computers, Volume 65, Issue 8, August 2016.

·        Fei Xu, Fangming Liu*, Hai Jin, Athanasios V. Vasilakos, "Managing Performance Overhead of Virtual Machines in Cloud Computing: A Survey, State of Art and Future Directions", ESI Highly Cited Paper, Proceedings of the IEEE (Impact Factor: 9.237, the most highly-cited general interest journal in electrical engineering and computer science), vol. 102, no. 1, Jan. 2014.

·        Fangming Liu, Zhi Zhou, Hai Jin, Bo Li, Baochun Li, Hongbo Jiang, "On Arbitrating the Power-Performance Tradeoff in SaaS Clouds", IEEE Transactions on Parallel and Distributed Systems, vol. 25, no. 10, 2014.

·        Guoming Tang, Weixiang Jiang, Zhifeng Xu, Fangming Liu*, Kui Wu, "NIPD: Non-Intrusive Power Disaggregation in Legacy Datacenters", to appear in IEEE Transactions on Computers, 2016.

·        Xiaomeng Yi, Fangming Liu*, Jiangchuan Liu, Hai Jin, "Building a Network Highway for Big Data: Architecture and Challenges", IEEE Network Magazine (Impact Factor: 3.72), Special Issue on Networking for Big Data, vol.28, no.4, July-August 2014. (The latest comprehensive survey on Networking Perspectives for Big Data in the literature)

·        Fei Xu, Fangming Liu*, Linghui Liu, Hai Jin, Bo Li, Baochun Li, "iAware: Making Live Migration of Virtual Machines Interference-Aware in the Cloud", IEEE Transactions on Computers, vol. 63, no. 12, 2014.

·        Wei Deng, Fangming Liu*, Hai Jin, Bo Li, Dan Li, "Harnessing Renewable Energy in Cloud Datacenters: Opportunities and Challenges", IEEE Network Magazine (Impact Factor: 3.72), vol. 28, no. 1, Jan. 2014. (The newest survey on Green Datacenters with Renewable Energy)

·        Fangming Liu, Peng Shu, Hai Jin, Linjie Ding, Jie Yu, Di Niu, Bo Li, "Gearing Resource-Poor Mobile Devices with Powerful Clouds: Architecture, Challenges and Applications", IEEE Wireless Communications Magazine (Impact Factor: 8.972, ranking Top#1 for impact and citations in Telecommunications according to the Thomson Reuters Journal Citation Reports), Special Issue on Mobile Cloud Computing, vol. 20, no. 3, June, 2013. (The latest comprehensive survey on Mobile Cloud Computing in the literature)

·        Fangming Liu, Shijun Shen, Bo Li, Baochun Li, Hai Jin, "Cinematic-Quality VoD in a P2P Storage Cloud: Design, Implementation and Measurements", IEEE Journal on Selected Areas in Communications (JSAC), Special Issue on Emerging Technologies in Communications, vol.31, no.9, pp.214-226, August 2013.

·        Fangming Liu, Bo Li, Baochun Li, Hai Jin, "Peer-Assisted On-Demand Streaming: Characterizing Demands and Optimizing Supplies", IEEE Transactions on Computers, vol. 62, no. 2, pp. 351-361, Feb. 2013.

·        Fangming Liu, Bo Li, Lili Zhong, Baochun Li, Hai Jin, Xiaofei Liao, "Flash Crowd in P2P Live Streaming Systems: Fundamental Characteristics and Design Implications", IEEE Transactions on Parallel and Distributed Systems, vol. 23, no. 7, pp. 1227-1239, July 2012.

·        Hong Zhang, Hongbo Jiang, Bo Li, Fangming Liu, Athanasios V. Vasilakos, and Jiangchuan Liu, "A Framework for Truthful Online Auctions in Cloud Computing with Heterogeneous User Demands", IEEE Transactions on Computers, Volume 65, Issue 3, March 2016.

·        Fangming Liu, Bin Luo, Yipei Niu, "Cost-Effective Service Provisioning for Hybrid Cloud Applications", ACM/Springer Journal on Mobile Networks and Applications (MONET), 2016.

·        Fei Xu, Fangming Liu*, Peng Yin, Hai Jin, "Network-Aware Task Assignment for MapReduce Applications in Shared Clusters", Journal of Internet Technology, Vol.16 No.2, 2015.

·        Fangming Liu, Peng Shu, "eTime: Energy-Efficient Mobile Cloud Computing for Rich-Media Applications", IEEE COMSOC MMTC E-Letter (IEEE Communications Society, Multimedia Communications Technical Committee), vol. 8, no. 1, January 2013.

·        Wei Deng, Fangming Liu, Hai Jin, Xiaofei Liao, Haikun Liu, "Reliability-aware Server Consolidation for Balancing Energy-Lifetime Tradeoff in Virtualized Cloud Datacenters", International Journal of Communication Systems (IJCS), 2013.

·        Jie Dai, Fangming Liu, Bo Li, Baochun Li, Jiangchuan Liu, "Collaborative Caching in Wireless Video Streaming Through Resource Auctions", IEEE Journal on Selected Areas in Communications (JSAC) special issue on Cooperative Networking Challenges and Applications, vol. 30, no. 2, pp. 458-466, February 2012.

·        Fangming Liu, Ye Sun, Bo Li, Baochun Li, Xinyan Zhang. “FS2You: Peer-Assisted Semi-Persistent Online Hosting at a Large Scale,” in IEEE Transactions on Parallel and Distributed Systems, vol. 21, no. 10, pp. 1442-1457, October 2010.

·        Jie Dai, Fangming Liu, and Bo Li, “The Disparity between P2P Overlays and ISP Underlays: Issues, Existing Solutions, and Challenges,” in IEEE Network Magazine (Impact Factor: 3.72) Special Issue on Network Science, vol. 24, no. 6, pp. 36-41, November 2010.

·        Wei Deng, Fangming Liu*, Hai Jin, and Dan Li, "Leveraging Renewable Energy in Cloud Computing Datacenters: State of the Art and Future Research," in Chinese Journal of Computers, vol. 36, no. 3, Mar. 2013.

·        Yueming Hu, Yueju Xue, Qing Li, Fangming Liu, Gabriel Y. Keung, Bo Li, "The Sink Node Placement and Performance Implication in Mobile Sensor Networks", in ACM/Springer Journal on Mobile Networks and Applications (MONET), Special Issue on New Advances in Heterogeneous Networking for Quality, Reliability, Security and Robustness, Vol. 14, No. 2, pp. 230-240, April 2009.

·        Fangming Liu*,Jian Guo,Jiangchuan Liu,Software Defined Networking: Technologies and Solutions toward an Open Network Eco-System,Science Foundation in China (《中国科学基金》英文版)国家自然科学基金委员会主办的综合指导性学术期刊,Vol. 25, No. 1, 42-56, 2017.

·        李丹,刘方明,郭得科,何源,黄小猛,软件定义的云数据中心网络基础理论与关键技术,电信科学,2014306):48-59. (2014中国计算机科学技术发展年度报告》专题报告之一,入选中国科协组织出版的学科3-5年权威性发展报告).

Conference Publications: 

·        Jian Guo, Fangming Liu*, Tao Wang, and John C.S. Lui, "Pricing Intra-Datacenter Networks with Over-Committed Bandwidth Guarantee", (Slides & Live Audio officially public, welcome download and post comments), in Proc. of USENIX ATC 2017 (one of the top system conferences, 60 accepted out of 283 submissions, HotCloud 2017 and HotStorage 2017 are co-located with USENIX ATC 2017), SANTA CLARA, CA, USA, July, 2017.

·        Xincai Fei, Fangming Liu*, Hong Xu, and Hai Jin, "Towards Load-Balanced VNF Assignment in Geo-distributed NFV Infrastructure", in Proc. of IEEE/ACM IWQoS 2017 (29 accepted out of 146 submissions, acceptance ratio: 19.9%), VILANOVA I LA GELTRU, SPAIN, June, 2017.

·        Yipei Niu, Fangming Liu*, Xincai Fei, and Bo Li, "Handling Flash Deals with Soft Guarantee in Hybrid Cloud", in Proc. of IEEE INFOCOM, (double-blind review), Atlanta, GA, USA, May, 2017.

·        Qixia Zhang, Yikai Xiao, Fangming Liu*, John C.S. Lui, Jian Guo and Tao Wang, "Joint Optimization of Chain Placement and Request Scheduling for Network Function Virtualization", in Proc. of IEEE ICDCS, Atlanta, GA, USA, June, 2017.

·        Weixiang Jiang, Fangming Liu*, Guoming Tang, Kui Wu and Hai Jin, "Virtual Machine Power Accounting with Shapley Value", in Proc. of IEEE ICDCS, Atlanta, GA, USA, June, 2017.

·        Yanqi Jin, Fangming Liu*, Xiaomeng Yi, and Minghua Chen, "Reducing Cellular Signaling Traffic for Heartbeat Messages via Energy-Efficient D2D Forwarding", in Proc. of IEEE ICDCS, Atlanta, GA, USA, June, 2017.

·        Tao Wang, Hong Xu, and Fangming Liu*, "Multi-Resource Load Balancing for Virtual Network Functions", in Proc. of IEEE ICDCS, Atlanta, GA, USA, June, 2017.

·        Tao Wang, Hong Xu, and Fangming Liu, "Aemon: Information-agnostic Mix-flow Scheduling in Data Center Networks", in The First Asia-Pacific Workshop on Networking (APNet), Hong Kong, August, 2017.

·        Youshi Wang, Fa Zhang, Shaolei Ren, Fangming Liu, Rui Wang, Zhiyong Liu, "Energy Efficiency in Colocation Data Centers: A Joint Incentive Mechanism Approach ", in The 8th International Green and Sustainable Computing Conference (IGSC), Orlando, Florida, USA, October 23-25, 2017.

·        Xiaomeng Yi, Fangming Liu*, Zongpeng Li, and Hai Jin, "Flexible Instance: Meeting Deadlines of Delay Tolerant Jobs in The Cloud with Dynamic Pricing", in Proc. of IEEE ICDCS, (68 accepted out of 386 submissions, acceptance ratio: 17%), Nara, Japan, June, 2016.

·        Zhifeng Xu, Fangming Liu*, Tao Wang, and Hong Xu, "Demystifying the Energy Efficiency of Network Function Virtualization", in Proc. of IEEE/ACM IWQoS, Best Paper Candidate, perhaps the 1st study on energy aspect of NFV in the literature, (only 27 are accepted as Full Papers, which results in an acceptance rate of 20.6%), Beijing, June, 2016.

·        Guangyuan Wu, Fangming Liu*, Haowen Tang, Keke Huang, Qixia Zhang, Zhenhua Li, Ben Y. Zhao, and Hai Jin, "On the Performance of Cloud Storage Applications with Global Measurement", in Proc. of IEEE/ACM IWQoS, (only 27 are accepted as Full Papers, which results in an acceptance rate of 20.6%), Beijing, June, 2016.

·        Haowen Tang, Fangming Liu*, Jacky Shen, Yuchen Jin, and Chuanxiong Guo, "UniDrive: Synergize Multiple Consumer Cloud Storage Services", in Proc. of ACM/IFIP/USENIX Middleware 2015, (ONLY 23 accepted out of 120 submissions), December, Vancouver, Canada, 2015.

·        Guoming Tang, Weixiang Jiang, Zhifeng Xu, Fangming Liu*, and Kui Wu, "Zero-Cost, Fine-Grained Power Monitoring of Datacenters Using Non-Intrusive Power Disaggregation", in Proc. of ACM/IFIP/USENIX Middleware 2015, (ONLY 23 accepted out of 120 submissions), December, Vancouver, Canada, 2015.

·        Tao Wang, Fangming Liu*, Jian Guo, and Hong Xu, "Dynamic SDN Controller Assignment in Data Center Networks: Stable Matching with Transfers", in Proc. of IEEE INFOCOM, (Acceptance ratio: 18.25%, Double-blind review), San Francisco, CA, USA, April, 2016.

·        Zhaojie Niu, Bingsheng He, and Fangming Liu, "Not All Joules are Equal: Towards Energy-Efficient and Green-Aware Data Processing Frameworks", in Proc. of IEEE IC2E 2016 (IEEE International Conference on Cloud Engineering), Best Paper Runner-Up, April 4-8, Berlin, Germany, 2016.

·        Tan Zhang, Xian Zhang, Fangming Liu*, Hongkun Leng, Qian Yu, and Guanfeng Liang, "eTrain: Making Wasted Energy Useful by Utilizing Heartbeats for Mobile Data Transmissions", in Proc. of IEEE ICDCS, (Acceptance ratio: 12.8%, 70 accepted out of 543 submissions), June-July, Columbus, Ohio, USA, 2015.

·        Zhi Zhou, Fangming Liu*, and Zongpeng Li, "Pricing Bilateral Electricity Trade between Smart Grids and Hybrid Green Datacenters", in Proc. of ACM SIGMETRICS, poster paper (only 57 papers, including 25 poster papers, were accepted among 239 submissions), June, Portland, Oregon, USA, 2015.

·        Zhi Zhou, Fangming Liu*, Zongpeng Li, and Hai Jin, "When Smart Grid Meets Geo-distributed Cloud: An Auction Approach to Datacenter Demand Response", in Proc. of IEEE INFOCOM (double-blind review with Acceptance ratio: 19%), April-May, Hong Kong, 2015.

·        Yipei Niu, Bin Luo, Fangming Liu*, Jiangchuan Liu, and Bo Li, "When Hybrid Cloud Meets Flash Crowd: Towards Cost-Effective Service Provisioning", in Proc. of IEEE INFOCOM (double-blind review with Acceptance ratio: 19%), April-May, Hong Kong, 2015.

·        Bin Luo, Yipei Niu, and Fangming Liu*, "Cost Effective Service Provisioning for Hybrid Cloud Applications", in The 11th International Conference on Collaborative Computing: Networking, Applications and Worksharing (CollaborateCom 2015) (newly promoted to CCF C class), Wuhan, China, Nov. 9-12 2015.

·        Zhi Zhou, Fangming Liu*, Bo Li, Baochun Li, Hai Jin, Ruolan Zou, and Zhiyong Liu, "Fuel Cell Generation in Geo-Distributed Cloud Services: A Quantitative Study", in Proc. of IEEE ICDCS, (Acceptance ratio: 13%, only 66 accepted out of over 500+ submissions), June-July, Madrid, Spain, 2014.

·        Shuopeng Zhang, Di Niu, Yaochen Hu, and Fangming Liu, "Server Selection and Topology Control for Multi-Party Video Conferences", in Proc. of ACM NOSSDAV, March, Singapore, 2014.

·        Jian Guo, Fangming Liu*, Xiaomeng Huang, John C.S. Lui, Mi Hu, Qiao Gao, and Hai Jin, "On Efficient Bandwidth Allocation for Traffic Variability in Datacenters", in Proc. of IEEE INFOCOM (Acceptance ratio: 19%), April, Toronto, 2014.

·        Jian Guo, Fangming Liu*, Haowen Tang, Yingnan Lian, Hai Jin, John C.S. Lui, "Falloc: Fair Network Bandwidth Allocation in IaaS Datacenters Via a Bargaining Game Approach", in Proc. of IEEE ICNP (only 46 accepted out of 251 submissions worldwide), October, Goettingen, Germany, 2013.

·        Zhi Zhou, Fangming Liu*, Yong Xu, Ruolan Zou, Hong Xu, John C.S. Lui, Hai Jin, "Carbon-aware Load Balancing for Geo-distributed Cloud Services", in Proc. of IEEE MASCOTS (only 44 accepted out of 163 submissions worldwide), August, San Francisco, USA, 2013.

·        Wei Deng, Fangming Liu*, Hai Jin, Chuan Wu, Xue Liu, "MultiGreen: Cost-Minimizing Multi-source Datacenter Power Supply with Online Control", in Proc. of ACM e-Energy'2013 (organized by ACM SIGCOMM Community), UC Berkeley, May 2013.

·        Zhi Zhou, Fangming Liu*, Hai Jin, Bo Li, Baochun Li, Hongbo Jiang, "On Arbitrating the Power-Performance Tradeoff in SaaS Clouds", in Proc. of IEEE INFOCOM (Acceptance ratio: 17%), April, Italy, 2013.

·        Jian Guo, Fangming Liu*, Dan Zeng, John C.S. Lui, Hai Jin, "A Cooperative Game Based Allocation for Sharing Data Center Networks", in Proc. of IEEE INFOCOM (Acceptance ratio: 17%), April, Italy, 2013.

·        Peng Shu, Fangming Liu*, Hai Jin, Min Chen, Feng Wen, Yupeng Qu, Bo Li, "eTime: Energy-Efficient Transmission between Cloud and Mobile Devices", in Proc. of IEEE INFOCOM (Mini-conference, Acceptance ratio: 25%), April, Italy, 2013.

·        Hong Zhang, Bo Li, Hongbo Jiang, Fangming Liu, Athanasios V. Vasilakos, Jiangchuan Liu, "A Framework for Truthful Online Auctions in Cloud Computing with Heterogeneous User Demands", in Proc. of IEEE INFOCOM (Acceptance ratio: 17%), April, Italy, 2013.

·        Wei Deng, Fangming Liu*, Hai Jin, Chuan Wu, "SmartDPSS: Cost-Minimizing Multi-source Power Supply for Datacenters with Arbitrary Demand", in Proc. of IEEE ICDCS'2013 (Acceptance ratio: 13%, only 61 accepted out of 484 submissions), Philadelphia, USA, July, 2013.

·        Wei Deng, Fangming Liu*, Hai Jin, Xiaofei Liao, "Online Control of Datacenter Power Supply Under Uncertain Demand and Renewable Energy", in Proc. of IEEE ICC, Budapest, Hungary, Jun. 2013.

·        Fei Xu, Fangming Liu*, Dekang Zhu, Hai Jin, "Boosting MapReduce with Network-Aware Task Assignment", in Proc. of ICST CLOUDCOMP, October, Wuhan, China, 2013.

·        Saumay Pushp, Chi Harold Liu, Fangming Liu, Junehwa Song, "Multi-Player Gaming in Public Transport Crowd: Opportunities and Challenges", in IEEE World Forum on Internet of Things (WF-IoT), March, Seoul, South Korea, 2014.

·        Wei Deng, Fangming Liu, Hai Jin, Xiaofei Liao, Haikun Liu, "Lifetime or Energy: Consolidating Servers with Reliability Control in Virtualized Cloud Datacenters", Best Paper Nominee (one of the 4 best papers among 90 papers), in Proc. of IEEE CloudCom, Taipei, Taiwan, December 2012.

·        Jie Dai, Bo Li, Fangming Liu, Baochun Li, Jiangchuan Liu, "Collaborative Caching for Video Streaming among Selfish Wireless Service Providers", Best Paper Award (one of the 14 best papers among 1070 papers), in Proc. of IEEE GLOBECOM, Houston, Texas, USA, September 2011.

·        Hao Yin, Heungsun Chang, Fangming Liu, Tongyu Zhan, Ying Zhang, Bo Li, "Discovering a Large-scale Internet Topology: Complementary and Contrast View", Best Paper Award, in Proc. of 11th IEEE International Conference on Ubiquitous Computing and Communications (IUCC-2012), Liverpool, UK, June 2012.

·        Fangming Liu, Shijun Shen, Bo Li, Baochun Li, Hao Yin, and Sanli Li, “Novasky: Cinematic-Quality VoD in a P2P Storage Cloud,” in IEEE INFOCOM, (Acceptance rate: 15.96%), April, 2011.

·        Jie Dai, Bo Li, Fangming Liu, Baochun Li, and Hai Jin, “On the Efficiency of Collaborative Caching in ISP-aware P2P Networks,” in IEEE INFOCOM, (Acceptance rate: 15.96%), April 2011.

·        Fangming Liu, Ye Sun, Bo Li, Baochun Li. "Quota: Rationing Server Resources in Peer-Assisted Online Hosting Systems," in IEEE International Conference on Network Protocols (ICNP), (36 accepted out of 197 submissions), Princeton, New Jersey, October 13-16, 2009.

·        Fangming Liu, Bo Li, Lili Zhong, Baochun Li, and Di Niu, “How Do P2P Streaming Systems Scale Over Time Under a Flash Crowd?” in International Workshop on Peer-to-Peer Systems (IPTPS), (20% acceptance rate), Boston, MA, USA, April 21, 2009.

·        Ye Sun, Fangming Liu, Bo Li, Baochun Li, and Xinyan Zhang, “FS2You: Peer-Assisted Semi-Persistent Online Storage at a Large Scale,” [Oral Presentation], in Proc. of IEEE INFOCOM, (282 accepted out of 1,435 submissions), Rio de Janeiro, Brazil, April 2009.

·        Fangming Liu, Ye Sun, Bo Li, and Xinyan Zhang, “Understanding the Roles of Servers in Large-scale Peer-Assisted Online Storage Systems,” in IEEE International Conference on Communications (ICC), Dresden, Germany, June 2009.

·        Ye Sun, Fangming Liu, Bo Li, Baochun Li, "Peer-Assisted Online Storage and Distribution: Modeling and Server Strategies," in International Workshop on Network and Operating Systems Support for Digital Audio and Video (ACM NOSSDAV), Williamsburg, Virginia, USA, June 2009.

·        Fangming Liu, Bo Li, Lili Zhong, and Baochun Li, “Understanding the Flash Crowd in P2P Live Video Streaming Systems,” (invited paper) in International Packet Video Workshop (PV), SEATTLE, WA, USA, May 11-12, 2009.

·        Bo Li, Gabriel Y. Keung, Susu Xie, Fangming Liu, Ye Sun, and Hao Yin, “An Empirical Study of Flash Crowd Dynamics in a P2P-based Live Video Streaming System,” [Oral Presentation], in Proc. of IEEE Globecom, New Orleans, LA, USA, November 2008.

·        Yueming Hu, Qing Li, Fangming Liu, Gabriel Y. Keung and Bo Li, "A Preliminary Study of Information Collection in a Mobile Sensor Network", in Proc. of ICST QShine 2008, Hong Kong SAR, July 2008.

·        [Ph.D. Dissertation] Fangming Liu, Large-Scale Peer-Assisted Online Hosting, Distribution and Video Streaming Systems: Design, Modeling and Practice, Ph.D. Dissertation, Department of Computer Science & Engineering, Hong Kong University of Science & Technology, Jan. 2011.

Technical Reports: 

·        Wei Deng, Fangming Liu*, Hai Jin, Chuan Wu, Xue Liu, and Bingsheng He, "Battery Matters: Rightsizing Energy Storage for Green Datacenters", Technical report, July, 2013.