NCCloud: Applying Network Coding for the Storage Repair in a Cloud-of-Clouds

Yuchong Hu, Henry C. H. Chen, Patrick P. C. Lee, Yang Tang

Proceedings of the 10th USENIX Conference on File and Storage Technologies (FAST ’12), February, 2012


To provide fault tolerance for cloud storage, recent studies propose to stripe data across multiple cloud vendors. However, if a cloud suffers from a permanent failure and loses all its data, then we need to repair the lost data from other surviving clouds to preserve data redundancy. We present a proxy-based system for multiple-cloud storage called NCCloud, which aims to achieve cost-effective repair for a permanent single-cloud failure. NCCloud is built on top of network-coding-based storage schemes called regenerating codes. Specifically, we propose an implementable design for the functional minimum-storage regenerating code (F-MSR), which maintains the same data redundancy level and same storage requirement as in traditional erasure codes (e.g., RAID-6), but uses less repair traffic. We implement a proof-of-concept prototype of NCCloud and deploy it atop local and commercial clouds. We validate the cost effectiveness of F-MSR in storage repair over RAID-6, and show that both schemes have comparable response time performance in normal cloud storage operations.



Columbia University Department of Computer Science