Research On The Problems About Running Distributed Simulation On Grid Environment

With the continuous development of human scientifical research and social practice activities, distributed simulation system is becoming more and more complex. Modern large scale distributed simulation places strongly requirements on huge amounts of computing and data resources, which will be geographically distributed and subjected to different organizations. As a newly arisen technology, computing Grid is an integrated computing and resource infrastructure that implements distributed resource coordinative operations and guarantees a certain level of QoS to users based on standardized, open and common protocols and interfaces. It provides favorable resource management platform for distributed simulation.To take advantage of computational Grid in distributed resources collaboration and management for distributed simulation technology development is an important, new research direction. This paper focuses on several important subjects involving in establishing distributed simulation application on Grid environment.Firstly, to construct Grid-based distributed simulation system, Grid-based Distributed Simulation Framework (GDSF) is proposed, which aims to providing a general implementation framework for establishing domain specific Grid-based distributed simulation system. Through the interaction of the simulation function modules of GDSF, Grid-based simulation platform provides universal basic services including modeling, simulation application development, simulation task submitting, computing resource scheduling, job monitoring and simulation results inquiry.Because of the particularity of distributed simulation application, to run it on Grid envirionment, many involved problems need to be researched. Then in this paper, three problems including extending HLA to Grid environment, simulation service resource organization and discovery, computing node selection for simulation application tasks scheduling, involving in simulation application development and execution on Grid environment, are studied.1) The HLA-based distributed simulation has been widely used. According to the requirement that integrating simulation federate modules developed based on HLA/RTI into Grid and organizing HLA-based simulation application in Grid environment, a system frame which realizes extending HLA/RTI to Grid environment based on Grid service is proposed. The frame aims to the advantage of Grid technology as well as the reusability and interoperability of simulation modules. And to integrate not-HLA-based simulation modules and other kinds of service into HLA/RTI system, according communication structure is given. The results of experiments of the prototype indicate the feasibility of the frame.2 ) Simulation service includes the sub-simulation-modules that participate in simulation application on form of service and the services that accessed in process simulation application execution. Since simulation service resource is the key resource that directly participates in simulation application, the effective management of it plays a prominent role in running Grid-based simulation application and is important for providing stable effective service to user. Subsequently, this paper studies the problem of simulation service resource management, which including: A local hierarchical-concentration and global dynamically-distributed simulation service resource organization and management model that considering simulation resource characteristic, semantic representation of simulation service, and the semantic-based matching of simulation service based domain ontology.3 ) Before simulation application task scheduling, according to the specific requirement of simulation user and application, in order to execute simulation application efficiently and stably, optimal selection of computing nodes is the key problem. This paper studies the problem of Grid computing node selection on the process of simulation application tasks scheduling. Firstly simulation applications are classified as compute-intensive applications and communication-intensive applications based on analyzing the common communication patterns of the simulation applications running on the Grid. And then according to requirement of different simulation application communication patterns, using computational economics and graph theory, the computing node selection models and optimization algorithms are proposed for the two kinds of simulation application respectively. The corresponding experiments verify that the algorithms significantly improve the resource use efficiency and application execution performance.