REEFS: An SDN Hyper File System Based on Erasure Coding

This study proposes a hyper file system, named REEFS (Resilient Erasure-codE File System), which is based on erasure code (EC) and integrates the technologies of software defined networking (SDN) and the distributed file system (DFS). REEFS utilizes the EC to encode a data object or file into n blocks for storing in n storage nodes in the DFS. REEFS is fault-tolerant since any k out of the n blocks can recover the data object. An algorithm, called Residual Network Multiple Shortest Path (RNMSP), is developed for finding the shortest paths from the file source to n storage nodes to reduce the file data block transmission latency, while maintaining high data availability. The shortest paths are used by the SDN controller to manage SDN switches to forward block data. The RNMSP algorithm is compared with other related algorithms to show its superiority in terms of the average file transmission latency.