Achieving efficient agreement within a dual-failure cloud-computing environment

Fault-tolerance is an important research topic in the study of distributed systems. To counter the influence of faulty components, it is essential to reach a common agreement in the presence of faults before performing certain tasks. However, the agreement problem is fundamental to fault-tolerant distributed systems. In previous studies, protocols dealing with the agreement problem have focused on a fully connected network or on a general connectivity. However, cloud-computing, an Internet-based development in which dynamically scalable and often virtualized resources are provided as a service over the Internet has become a significant issue. In a cloud-computing environment, the connected topology is not very significant. Therefore, previous protocols for the agreement problem are not suitable for a cloud-computing environment. To enhance fault-tolerance, the agreement problem in a cloud-computing environment is revisited in this study. The proposed protocol is called the Dual Agreement Protocol of Cloud-Computing (DAPCC). DAPCC achieves agreement on a common value among all nodes in a minimal number of message exchange rounds, and can tolerate a maximal number of allowable faulty components in a cloud-computing environment.