The Replica Creation Mechanism Of Grid Service With State Based On Virtual Workshop

With the development of Grid technology, the Grid begins to adopt the OGSA model instead of the five layer sandglass model now. The OGSA model is a model of service Oriented and the combining result of the Web Service and Grid technology, which is a kind of development direction about future computing mode and built by elementary and advanced services. A majority of Grid Service have state, which is different from the static resource, and can change their state with the time and the call from the Grid users. For the sake of avoiding the bottleneck of access the Grid Service, access Grid Service handy and achieving load-balance, we should realize the replication of Grid Service with state.The research about Grid replica is a difficulty in Grid research. The replica creation technology can replicate the files, the objects, a great deal data and the wide data through the research of many experts now. Whereas those resources are the static resource that the state of datum is not changing, so the replica creation technology can not realize the replication of Grid Service with state.The replication of Grid Service demands the replication of many resources which are changing their state dynamic, such as the constructing of hardware, the replication of software, the conformation of the state resource and their state, the replication of the memory data.Based on those problems, we thoroughly analyze the environment and the mechanism about Grid Service running, sufficiently consider the characteristics of dynamic changing Grid Service and reconstructing state resource, then we advance the replica creation mechanism of Grid Service with state based on virtual workshop--Ragsres. The mostly work is listed as follows.(1) On the base of thoroughly researching Grid replica management service, we sufficiently analyze all kinds of states during state Grid Service replication and consider thoroughly the characteristics of dynamic changing about Grid Service and resource, so we design the architecture of Ragsres. (2) We adopt the virtual workshop, which is realized by virtual machine technology and utilize the outstanding isolation properties and the customized, controllable execution environment of virtual workshop, to realize the replication of the hardware and the software.(3) We adopt the state resource modeling technology of Web Service to realize the replication of the state resource and their state. We receive all kinds of information about the state resource from Global Element Declaration and then reconstruct the state resource and their state.(4) Based on the principle of snapshot technology on virtual machine monitor, we translate the dynamic data from memory into the data in disk and then reconstruct the memory data in the new execution environment through virtual workshop to achieve the replication of Grid Service memory data.When we accomplish those replication parts step by step, we can receive a new Grid Service. The result of experiment shows Ragsres can effectively replicate the Grid Service. When all the resources can be received during the replication, Ragsres can replicate the Grid Service in a very short time and resolve the problems about access bottleneck and over load very well. So Ragsres provide a kind referenced approach in the Grid Service replication research.