MultiRep: asynchronous multi-device consistency

Abstract

Nowadays, people increasingly use multiple devices to manage and share information anywhere anytime. Users are increasingly spreading large sets of files and folders among several devices. Since users cannot know at one device which files/folders are stored by other devices, data management across multiple devices has become a very difficult task. For instance, when one user needs an object that is not stored on the device being used, he/she needs to manually explore the entire object collection, which is spread across multiple devices. Additionally, different versions of files are created on multiple devices raising a consistency problem. Most current solutions ensure data management and consistency across devices through central servers or Internet services. Since portable devices have intermittent network connection or no connection at all to access these services, it is essential to take advantage of proximity between devices to synchronize data among them. This paper introduces MultiRep, a single-user file synchronizer middleware that provides the user with information about the location of files and folders stored on multiple devices. MultiRep is a totally decentralized system based on optimistic replication. It ensures eventual consistency among multiple devices through pair-wise interactions, reporting all relevant information about conflicts to the users.