Based On The Reserved Delay Early Admission Control Algorithm Research

Advance reservation of resource is the important guarantee of Quality of Service. In the current research, all the admission control researches based on advance reservation adopt Immediate Scheduling Admission Control algorithm (ISAC). However, if the endtime of the current job is different from the starttime of the following one, there will be idle area between the two jobs. The idle area which results in the reject of other jobs is called resource fragment. The job acceptance rate and resource utilization will be reduced by the generation of the resource fragment.The Delay Scheduling Admission Control algorithm (DSAC) which propounded in this paper is for resolving the above-mentioned issue. The main idea of the DSAC algorithm is that when a job arrives we decide whether accept it by the usage of the current resource. If there is no resource can meet the job’s need, it will be rejected. We will accept the job if the current resource can meet its need. However, we don’t make the decision where to put the job immediately. We just take down the schedule program of the job and schedule it when the job satisfies a special condition. The idea of delay scheduling is used to improve the flexibility of job scheduling. In this paper, the problem of advance reservation is divided into admission control and job schedule two parts and each part is described in detail. We also verify the impact of DSAC and ISAC algorithm on job acceptance rate and resource utilization in the setting of multi machines and single processor.In this paper, we implements DSAC algorithm on the simulator based on discrete event driven by which we contrast the job acceptance ratio and resource utilization through First-fit, Best-fit and Worst-fit policy. And then we study the impact of different machine number, arriveFactor and deadlineFactor on DSAC algorithm. The simulation results show that the advantage of DSAC algorithm on job acceptance rate and resource utilization.