Research And Optimization Of Dynamic Transfer Mechanism Of Virtual Machine In Cloud Computing

Virtual machines not only provide efficient and secure computing resource containers,but also smooth migration between multiple physical hosts.Dynamic migration of virtual machines is a powerful management tool based on multiple virtual machine environments.It has become a powerful tool for system maintenance,load balancing,fault tolerance and energy saving,especially in clusters or data centers.In a virtual machine-based cluster,multiple virtual machines share a pool of physical resources.Due to the dynamically changing workload,some nodes are usually not fully utilized,while other nodes may become overloaded.In order to balance the load between nodes,some virtual machines will migrate from overloaded machines to light-load machines based on regularly collected resource usage.But also because of the health of the node,power budget and many other issues,the need for dynamic migration of virtual machines.The current pre-copy algorithm is widely used by virtualization platforms such as Xen and VMware.In this paper,Xen is selected as the experimental platform for the dynamic migration of virtual machines to study,mainly for high load situation.In the case of high load,the pre-copy algorithm in the iterative copy phase will appear a lot of memory repeat transmission situation,will lead to iterative copy of the transmission process due to the transmission time is too long to cause the next transmission to produce more repetitive memory,resulting in a vicious cycle,Affect the efficiency of migration,and may even cause migration failure.So in the case of high load,the important factor affecting the transmission efficiency is the iterative transfer time of each iteration of the iterative copy stage.The current method of optimizing the transmission efficiency is to predict the probability of dirty memory to avoid the repeated transmission,the reasonable allocation of limited bandwidth to balance the transmission speed and the transmission of each round of transmission to improve the transmission speed and so on.In this paper,the improved bandwidth dynamic allocation algorithm is used to dynamically allocate the bandwidth of each transmission,balance the transmission time of each round,and prevent the next dirty memory from becoming too long for a certain transmission time to form a vicious circle Happening.At the same time,an improved memory adaptive compression algorithm is proposed to allocate the memory for each iteration to its compression algorithm,reduce the iterative transmission time and shorten the total migration time.At the end of this paper,the improved algorithm and the pre-copy algorithm and the improved algorithm are tested.The experimental results show that the improved algorithm has different degree of optimization and performance improvement in the case of high transmission time and downtime.