Dynamic Reconfiguration Of Service Grid Mechanism Study

Along with the development of Service Computing,it become the hotspot to construct the application with the service component distributed on the grid environment. As the promising distributed computing mode,service grid can build the giant application base on the resources on the internet.But in the field of service grid,there is a urgent problem which remains unsolved,the problem is how to reconstruct the distributed system based on grid dynamically under the dynamic,distributed,the dynamic needs of user and environment,in order that the application can prevents the condition that the application occur interrupt,postpone of the service time or other serious quality problems because of hard-shelled configuration.Actually,dynamic reconfiguration problem is also named "dynamic management of virtual organization",it can provide the adaptation ability to the grid application,this ability is one of the sixty-four-dollar questions in the gird field.Further research indicates that dynamic reconfiguration or self configuration is also a key problem that urgent to resolve in Multi-agent as well as Autonomic Computing,in multi-agent,it called "run-time reconfiguration and redesign";and in automatic computing,it called "self-management of computing system".The emphasis of this paper is to research the dynamic reconfiguration mechanism with service grid.Grid especially service grid is a new research field,some pre-works has been done by some researchers,but the models or methods are very general,can't provide the guidance to build dynamic reconfiguration systems;in this paper,A Dynamic Reconfiguration Model based on OGSA is proposed,dynamic reconfiguration implementation architecture and algorithms are designed to provide dynamic reconfiguration of grid,so the grid application can obtain the consist and continuous service.The contributions of this paper are the following four aspects:1,Modeling the grid service that support dynamic reconfigurationThe interface level of the dynamic reconfiguration service component behaviors is analyzed,then the ASM(Abstract State Machine)was used to model this king of component;the contents conclude the characteristic,the external interface and others;2,Modeling the service grid with dynamic reconfiguration abilityThe dynamic reconfiguration service grid model named DRGM based on OGSA is proposed;the key elements of this model have been clearly defined,and the rules to deal with the dynamic events have been presented.This research will,on one hand,probuce new dynamic reconfiguration techniques for service grid systems,and will also contribute to grid computing.3,Designing algorithms for dynamic reconfigurationIn order to support the dynamic reconfiguration behaviors,a serial algorithms have been designed and proposed;The GSLA was used to search and locate the grid service, The dynamic reconfiguration event rules were used to treat with the reconfiguration event, the execution of the algorithm can support the dynamic reconfiguration behaviors. Experiments show that this algorithm can work efficiently.4,Constructing the dynamic reconfiguration system and analyze the model and effectsAfter the dynamic reconfiguration model and methods were proposed,the DACSC application was selected as the scenario of this paper.We construct the dynamic reconfiguration service component with WSRF,and more the grid application antetype was finished;Experiments have done with the antetype,the result show that the application can adapt to the different dynamic conditions.