Design And Implementation Of Job MetaScheduler Subsystem In Grid Environment

Grid,an Internet infrastructure which is highly promoted internationally,creates a higher level distributed resource sharing environment by aggregation of resources spread around the Internet."Grid Service System" is an implementation of grid in the specific domain of high performance computing.It integrates supercomputers and clusters to form a high performance computing user oriented Grid computing environment.The Job MetaSchduler Subsystem(JMS)is an important part of Grid Service System.It is responsible for dealing with the request of a job which an user has submitted from the portal system,and then,it packags the request to an job object that will be dealed with in some dagree by a way of object oriented.At last,JMS will select the favorite resource for the job to execute on.The subsystem emphasizes the software hierarchy.JMS is designed by being divided into six layers,and the order is:Security Layer,Interface Layer,Control Layer,Service Layer,Link Layer,General Layer.These layers are all independent and the interfaces between them are simple.During the course of design,the author follows the Web Services stardard and implements the character of system such as dependable,configurable,surveyable and maintained by applying some techniques such as XML,AXIS,Data Persistence,Object Serialization etc.The design of an environment of job-handling at the Service Layer is the role of the subsystem.lt adopts a muti-queue structure to simulate the process of job-handling.The job object is handled such as job prehandler,job scheduler,resource-selection and submition during the process of its movement in the muti-queue.On the job handler pattern,it adopts a method of batch handling;On the scheduling strategy,it adopts a muti-strategy pattern that can be inserted in;On scheduling algorithm,it adopts a new algorithm that adjusts job's priority based on user's satisfactory.