Research On The Mechanisms Of Dynamic Virtual Machine Migration Oriented High Availability Services

Virtualization technology has been widely used in cloud computing, data center and cyber physical systems. However, as the system scale expands unceasingly and business lines growth continuously, how to ensure the system running stably and efficiently,reduce shutdown requirements caused by updating, repairing and maintaining, keep continuity of missions, how to stand the racket of special harsh environment, unpredictable disasters ,malicious attacks and faulty operation, reduce the impact of unplanned downtime,thereby provide a more stable and highly available basic platform has been the urgent priority of special computer system development. In this paper, we propose a dynamic virtual machine migration mechanism which improves availability of Foreign Service under the special environment. The mechanism includes a set of dynamic memory allocate mechanisms in a single-machine environment and a set of dynamic virtual machine migration mechanisms in a multiple machine environment.We propose a dynamic memory management mechanism in single environment with the goal of availability growth, which includes a fast memory adjustment strategy with memory recycling, memory increasing, and memory adjustment. Experimental results show that, in order to satisfy the memory requirements virtual machines need, this memory management mechanism can recycle a large amount of free memory in virtual machines rapidly; in the aspect of increasing memory, using exponential growth mode can also satisfy high memory requirements in a short time, which has improved availability of the virtual machine requiring memory urgently; and in the case of shortage of memory resources, the model can also give priority to meet the demand of virtual machine requiring memory urgently, which has avoided availability falling due to shortage of memory resources. This mechanism reduces the occurrence of unnecessary migration with the improvement of memory utilization.The dynamic migration mechanism of virtual machines in multi-computer environment that we proposed has a comprehensive analysis instead of only concerning the computing resource information by adding the hardware statement, which proposes Node Reliability to help judging trigger conditions and. selecting the destination host. Experimental results show that, the mechanism can provide a more reasonable comprehensive assessment in allusion to the environment of computational nodes, and a more effective virtual machine migration trigger aiming at both computing resources and hardware status of nodes in order to reduce the risk of task running on virtual machines. Also, this mechanism can achieve effective filtration in face of Occasional Stab, at the same time, achieve a valid trigger when reliability changes frequently, which both avoids unnecessary trigger and also identifies instability computational nodes to ensure stability of the task. In the selection of destination host,avoiding single selection of destination host only on the core purpose of current status of computational nodes, this mechanism adopts the method of adding virtual machine to analyze historical data, which improves the availability of migration mechanism.