Distributed directories synchronization method based on Hash tree
Bao Ai-hu · Journal of PLA University of Science and Technology · 2013
In cloud storage application scenarios,users usually need to modify their working directory copies in different terminals,and then it becomes an important issue for efficient data synchronization between distributed replications of the working directory.Optimistic replication and the eventual consistency theory was used as reference,a distributed working directory synchronization system named HTD2Sync was designed and implemented.In HTD2Sync,file hash value was imported as foundation to detect conflicts in concurrent file synchronization,so that most of the pseudo-conflicts were filtered;two conflict types and six conflict scenarios in directory replication synchronization were analyzed,and the corresponding resolution methods were proposed;Ordered Hash Tree(OHT)was used to represent the character of user working directory replication,and the create and update methods of OHT were introduced;the distributed directory synchronization method based on OHT was proposed,and meanwhile,its progress and core operation steps were elaborated,and algorithm to compare OHT named COMPARE_OHT was also proposed.Experiments show that HTD2Sync can detect client file changes quickly,and also has a good performance in detecting cloud file changes.