Research On PC Cluster And Application In Online Exercise Judge System

Computer programming is a fundamental course for students major ininformation technology, as well as the basic technique for the professionalswho work in IT domain. Learning programming has a very obvious differencefrom learning other subjects. That is the especially high demands ofprogramming practice besides the conventional concepts and theory studying.It is almost impossible for the instructors to judge all of the assignedprogramming works submitted by the learners in time. Therefore, it will bequite significant to develop an online automatic judge system, which canjudge the correctness, efficiency and robusticity of the program codesubmitted by learners and give proper feedback to the learners. This systemcan be in service 24 hours and 7 days without any geographic boundary easily,and also reduce the instructors' artificial labor load of code checking greatlyand therefore concentrate more attention to give learners key guides andpromote teaching effects. The main works of this paper are as follows:1. Based on a research and a comparison on the online judge systemdeveloped both domestic and international, selected the Client/Servermodel and the Linux+Apache+PHP+MySQL+C platform, designedthe key functions of the online judge system and realized eachfunction module.2. Based on a research and an analysis on the cluster strategy, presentedan approach of LVS PC cluster technology and system architecture tobuild the model for the online judge system. The experiment systemrevealed a good server load balance as well as a highperformance/cost ratio.3. Based on an analysis of the basic principle and prevalentmethodology of network attack, and the consideration of thecharacteristics of the operating system platform and the online judgesystem, presented asystem security strategy, the experiment systemshowed a high security toward the prevalent network attacks.