关键词: 自治移动云, 存储服务, 数据副本维护, 数据丢失率

Abstract: Concerning the scenario of localized geographical area, the autonomous mobile cloud is capable of providing provisional storage services for cloud users. However, because of the limitation of storage space in mobile nodes, maintaining the data persistence becomes more difficult. This paper proposes a space-limited storage protocol for  autonomous mobile cloud named as SLAMS protocol. The central idea of this protocol is that K copies for each data block are kept via periodic communications among mobile nodes, and data block copies are stored into nodes with larger free storage space. This paper presents the specific data copy maintaining mechanism, corresponding data structures and algorithms, and detailed design of SLAMS protocol, respectively. The simulation results show that, compared with current major solution Phoenix, the data lost rate can be reduced by up to 50%, the time of convergence can be reduced by up to 95%, and the overhead of data block storage can be reduced by up to 90% in the SLAMS protocol. Besides, the SLAMS protocol can effectively increase the probability of K copies by up to 40% for each data block in case that mobile nodes have limited storage space.

Key words: autonomous mobile cloud, storage service, data copy maintenance, data loss rate