Modelling multi level consistency in erasure code based storage systems

In the internet era, cloud storage services are in high demand. Due to huge volumes of the present day big data, cloud service providers look for alternatives for data replication, which has been traditionally used for providing fault tolerance and availability. If three copies of data are maintained for ensuring availability, then there is 200% storage overhead in replication based storage systems. Erasure code based storage is proving itself the most suitable alternative to replication schemes. Hardware assisted encoding, decoding process and research outcomes on data updates from various research communities, indicate a promising future for erasure code based storage systems for hot data storage. In this paper, a new protocol is proposed which shows how to provide different types of consistency in erasure code based storage systems in concurrent data access scenarios where failures of components are anticipated. We have developed protocols and data structures for implementing the strong, eventual and monotonic types of consistencies. The proposed consistency model has been tested successfully and the results are promising.