混合云环境下利用世系保障数据一致性的研究

Data provenance based consistency service for hybrid cloud

混合云环境下,公有云与私有云共同为用户提供服务,公有云中的应用可能需要频繁读取私有云中的数据,通过复制私有云中的副本到公有云中可降低网络开销,但不同云中文件副本的动态更新会导致云中各个副本的不一致性。提出了一致性服务,该服务由一致性维护模块和一致性检测与恢复模块两个部分组成。一致性维护模块通过发送文件的更新消息的方法维护副本的一致,降低了系统的响应时间;一致性检测与恢复模块利用世系的思想,通过对比副本的世系记录来检测副本的一致性,可将副本不一致状态恢复成一致状态。实验证明混合云下利用世系一致性服务是可行的,由此带来的通信和存储开销在可接受范围内。

Under hybrid cloud environments, public cloud and private cloud work together to provide service for users. Appli- cations in public cloud may read data stored in the private cloud frequently. This could be realized by copying a private cloud replica to the public cloud, and it could reduce network overhead. Futher mord, file copies dynamically update in the cloud, which would lead to other inconsistencies of cloud copies. This paper presented a consistency service, which consisted of a consistency maintenance module, and a consistency checking and recovery module. The module of consistency maintenance could maintain consistency of file copies by sending updating message. This method could reduce the responsing time to the ap- plications in the public cloud. Consistency checking and recovery module utilized the idea of data provenance, by comparing provenance record of copies to detect consistency of copies. Meanwhile it could make a copy recover to a consistent state. Ex- periments show that the consistency service for hybrid cloud is flexible, and the communication and storage overhead is accepta- ble.