Chapter Two towards Autonomic Transactional Replication for Cloud Environments

In recent years, in-memory transactional data platforms, often referred to as NoSQL data grids, have emerged as a reference solution for transactional data management in the cloud. In these in-memory platforms, replication plays a role of paramount importance for fault-tolerance purposes, given that it represents the key means to ensure data durability in the face of unavoidable node failures. Unfortunately, despite the abundance of approaches in the area, existing replication schemes still fall short of addressing one of the key requirements of cloud computing environments: ensuring optimal efficiency when deployed over elastic infrastructures that dynamically expand/reduce the number of (physical or virtualised) resources in response to fluctuations of workload characteristics. Tackling this issue is a key goal of the Cloud-TM project, a recent EU funded initiative that aims at developing a self-tuning, elastic transactional data platform tailored to meet the elasticity requirements of cloud computing infrastructures.