Abstract: Redundant data backup is one of the important guarantee mechanisms to ensure the reliability of data under the cloud data center. OpenStack is an open source platform for cloud computing which belongs to IaaS layer private cloud services, and it has been widely used in the industry. The Swift module, which is one of the OpenStack’s modules, uses the consistent Hash algorithm in order to choose the replica backup node by a Ring to complete  the load balancing and data backup. By analyzing the implementation mechanism and code of Swift, this paper points out the shortcomings of the selection of the nodes in the replica placement node, and then puts forward the optimization selection strategy ABS (Adaptive Backup Strategy). On the basis of real-time monitoring of the current storage node load, the mechanism adaptively selects the recently available nodes to complete the backup in order to optimize the overall backup efficiency based on the predetermined threshold and lower limits. By comparing with the existing copy backup strategy and experimental verification, it shows that ABS improves the four reading and writing performance of the system by 3.4%~9.1% on the basis of maintaining the balance of data copy allocation, and achieves the purpose of optimizing access.

Key words: copy, backup, Swift, ABS