Abstract
Due to the high availability of the Internet, many large cross-organizational collaboration projects have emerged. One of the fundamental requirements of these collaboration efforts is a storage system to exchange data. This storage system must be highly scalable and can efficiently aggregate the storage resources contributed by the participating organizations. In this thesis, we propose Collaborative File Repository (CFR), a storage system for large scale collaboration projects. CFR uses peer-to-peer techniques to achieve scalability, efficiency, and ease of management. In CFR, storage nodes contributed by the participating organizations are partitioned according to geographical regions. Files stored in CFR are automatically replicated to all regions. Furthermore, popular files are duplicated to other storage nodes of the same region. By doing so, data transfers between users and storage nodes are confined within their regions and transfer efficiency is enhanced. The system maintenance procedure of CFR can be mapped to the Coupon Collection problem, and we propose an optimal solution to the problem to reduce system maintenance overhead. Experiments show that our replication can achieve high efficiency with a small number of duplicates.