Classic Replication Techniques on the Cloud

The limited scalability of cluster-based databases has motivated a new class of storage systems based on the cloud paradigm, which favor availability over data consistency to provide highly elastic and scalable services. This paper presents a distributed storage architecture that combines a cloud inspired scheme with traditional database replication concepts to provide transactional support as well as high availability by offering different consistency levels according to the demands of client applications, thanks to a replication strategy based on epidemic updates. We also include an analytical model for computing the scale out of a distributed system that can be used for adjusting the configuration of the proposed architecture.