Research On Data Replication Technology In The Mobile Computing Environments

As the development of mobile communications,database,distributed computing technology and the popularity of smart phones,panel computer,other mobile computing devices makes we are from the personal computing era to the era of ubiquitous mobile computing.Mobile computing environment has node mobility,network conditions diversity,network communication asymmetry.But at the same time,mobile computing environment is mobile power supply capacity limited and resources limited and network frequent disconnected and low reliable.In mobile computing environment,data replication technology which through storing the data on multiple nodes to improve the data access efficiency,reduce communication costs,reduce the consumption of wireless link bandwidth and energy and other resources,balance the system's load,guarantee data fault tolerance effectively etc.In this paper,firstly,studied the data replication technology in mobile environment of fixed station supporting.In the selection of the replicated data item,through the analysis of the data access of nodes to get the value of data item to select the data item higher than the average value to create a copy of the data.In the selection of data storage nodes,through the analysis of the node's performance in the data query path to place the data replica copy according to the performance of the nodes and the overhead required.Second,studied the data replication technology in mobile environment of ad-hoc network.Secondly,in data replication process,sort data according to the size of the data access frequency within the group,place replica according to the node's access frequency of data in the group.When a node runs out of space using the correlation algorithm to remove selection.In data replication process,according the size of the copying data to calculate the power consumption.Node is no longer for data replication when it's power is less than a certain threshold.To calculate the node's performance by calculate node's CPU capacity,power,hard disk capacity,the failure rate and other factors.Selecting the node with the max performance in the group to store the data which realize the substitution of low power node.Finally,compared with related data replication technology through the simulation experiment to show that the data replication technology proposed in this paper can make the data access efficiency improved.