Study On Grid Scheduling Of Super-peer Model Based On QoS

Grid computing of super-peer model achieves a balance between the efficiency of centralizedsearch and the expansibility owned by distributed search. A super-peer controls the access to aseries of ordinary nodes, while super-peers connect to each other use P2P way. It has greatdifference compared to traditional centralized grid and distributed grid in terms of resourcemanagements, which makes task scheduling mechanism complicated.The already existed study on grid scheduling of super-peer model has shortcomings asfollows: Just take one dimensional parameter-time into consideration, seldom think about users’multiple QoS requirements, this may contribute to invalid resource allocation; Scheduling targetsare mainly metatasks which are independent with each other. However, grid applications arenormally compound tasks; Scheduling strategy lacks formal modeling and theoretical analysis,while the sophisticated process of task scheduling is parallel, distributed and dynamic. So, the maincontent of this paper is:Firstly, we summarize grid of super-peer model. As the method and performance of resourcediscovery is strictly associated with the distribution of resource types, grid of super-peer model canbe divided into two categories according to the resource registration:1.Resource nodes within asuper-peer domain are gathering together by geographical boundaries.Every node may hasresources of various types.2. Resource nodes within a super-peer domain are clustering together bymeans of semantic similarity. All nodes in one super-peer domain share the same resource type.Then, we introduce some key issues that need to be noticed in grid scheduling of super-peer model:compound tasks, resource allocation method based on market mechanism, application of Pricetimed Petri net in grid scheduling.Lastly, we do detailed study on grid scheduling of super-peer model of the two kinds.For each kind of grid of super-peer model, we originally propose a compound task schedulingalgorithm suitable to its characteristics, which takes users’ time deadline, cost limit and the weightparameters between them into consideration. We use price timed Petri net which is a powerfulgraphical and mathematical tool to hierarchically model grid scheduling in order to have betterunderstanding about it. Reachable task graph of Petri net model is constructed to analyzescheduling performance, such as scheduling time, cost, throughout capacity and load balance, etc.The scheduling algorithm is tested and verified to be effective through an example. Related workcan make up for shortcomings about study on grid scheduling of super-peer model, and has great significance on promoting research on basic theory of the grid, guiding the construction andimplement of real grid systems of super-peer model.