Developing a VM-based hybrid DNS system with high availability
In this paper, we proposed to develop a set of low-cost, virtual machine-based hybrid DNS scheme (i.e., a frontend + multiple backend systems) with a scalable capability to provide DNS services with high availability. In this study, we had built two use case diagrams, namely the frontend (i.e., load-balancer) and the backend (i.e., DNS resolving) subsystems, for modeling the overall system. Moreover, we had developed a two-phase DNS health checking algorithm and designed two testing cases to help implement and evaluate the system. For validating the hybrid scheme, we had deployed and run the proposed DNS system for more than 2 years on our campus network. Based on the collected statistics, we had ensured that the proposed DNS systems could offer the expected DNS services with load-sharing capability and high availability for serving daily DNS queries on a regular basis and run smoothly.