Mobile Cloud-of-Clouds Storage Made Efficient: A Network Coding Based Approach

Cloud-of-clouds storage is a viable means to ensure security and reliability of distributed data storage, where data are encrypted, encoded, and stored in multiple clouds. However, it is a great challenge to adopt such a paradigm in mobile devices (e.g., smartphone). Mobile devices are generally incapable to perform the heavy-weight operations (i.e., data encryption, encoding, and transmission) required in such a paradigm, given the limited resources in such devices. This paper focuses on addressing this challenge, i.e., improving data storage performance in mobile cloud-of-clouds storage systems. The key of our proposal is to allow the low-capability mobile devices to offload the computational and transmission overhead to the clouds. In other words, we propose a Network Coding based Cloud-of-clouds Storage (NCCS) scheme, where the clouds can encode and exchange data collaboratively. We consider two state-of-the-art cloud-of-clouds storage approaches, i.e., AONT-RS and CAONT-RS, as example cases to deploy our scheme. Accordingly, we propose their network coding-based enhancements, namely NAONT-RS and NCAONT-RS. We implement a prototype cloud-of-clouds system to verify the efficiency of our proposal. We deploy the prototype on Microsoft Azure and conduct extensive experiments with real-world traces. The experimental results show that NAONT-RS and NCAONT-RS can reduce the time of data storage process by up to 50% and improve the throughput by up to 110% compared with their original versions, i.e., AONT-RS and CAONT-RS.