Operational transformation based reconciliation in the FEW File System

Optimistic replication is used to provide high data availability and support for disconnected operation in mobile computing environments. As this approach may lead to concurrent updates, a system based on optimistic replication must include a replica reconciliation mechanism. In this paper, we describe the reconciliation mechanism implemented in the Files EveryWhere (FEW) le system for mobile computing. Our reconciliation approach is based on operational transformation. However, as our system supports only asynchronous collaboration, we propose a set of new techniques for operational transformation. First, we propose a new technique for handling operations in operational transformation algorithms that supports ef cient epidemic dissemination. Second, we propose a new set of transformation functions that explicitly handle line versions in text les. Finally, we propose a set of transformation functions that explicitly handle le versions for opaque les. Our approach is implemented as a new le system, thus allowing users to continue using their favorite applications. Author