Scalable Service Oriented Replication in the Cloud
Tao Chen, Rami Bahsoon · 2011
Replication techniques are widely applied in and for cloud to enable elastically scalable and highly available service. Consistency and scalability requirements need to be ensured for the applications deploy in cloud. However, a major lack of existing service oriented replication approaches is that they only allow either rather restricted consistency or none at all, consequently the system may violates consistency requirements or does not scale well. In this paper, we present Scalable Service Oriented Replication (SSOR), a middleware solution that satisfies application's requirements in service replication. We propose the notions of region and the relevant service oriented requirements policies, by which trading between consistency and scalability can be handled. We solve atomic broadcast as a sub-problem by demonstrating Multi-fixed Sequencers Protocol (MSP). We also apply a Region based Election Protocol (REP) that elastically balances the workload amongst sequencers. Preliminary experiments show that the proposed approach achieves better scalability with desirable consistency constraint.