Time-efficient Caching and Regeneration Scheme of Distributed Storage Systems

Prof. Xin WANG
Fudan University
Wednesday, 3 October, 2012
4:00 - 5:00 pm
Room 1009, William M. W. Mong Engineering Building

Distributed storage systems are able to provide time-efficient data access services, by connecting low-end storage devices in the network. In practice, however, data stored in distributed storage systems cannot be accessed temporarily or get lost permanently due to failures of storage devices. Lost data can be repaired through a process called data regeneration. In this project, we optimize the process of data regeneration to reduce time spent and bandwidth consumed during regeneration, and thus to improve the reliability and the availability of data stored in distributed storage systems. Rather than conventional (star-structured) data regeneration process that the newcomer acquires data from multiple providers simultaneously, we propose tree-structured regeneration processes including single-tree and multiple-tree regeneration processes. Moreover, because commodity routers are powered with higher and higher computing and storage abilities, and are becoming service-oriented and users' need-oriented, we are able to utilize routers during regeneration to encode data by random linear codes and to cache coded data. Thus, we can further reduce the bandwidth consumption during regeneration and thus achieve less regeneration time and higher successful probability of data regeneration.



Xin Wang is currently a full professor in the School of Computer Science at Fudan University. He received his BS degree in information theory and MS degree in communication and electronic systems from Xidian University, China, in 1994 and 1997, respectively. He received his PhD Degree in computer science from Shizuoka University, Japan. In 1995 and 1998, he had worked on China's first telecom-level video conferencing systems and DVB-S systems, in Huawei Tech. Ltd., Shenzhen, China. His research interests include quality of network service, next-generation network architecture, mobile Internet and network coding. He is a senior member of CCF, and a member of IEEE. Currently he is in charge of research projects from Natural Science Foundation of China (NSFC), China high-tech project plan (863 Program), Shanghai Municipal R&D Foundation and etc. Now he leads the joint Android Lab of Fudan-Google.