Network Teaching-Assisted C/S System

This paper developed a Network Computer-Assisted Instruction to solve those questions that the uneasy intercommunion and the low efficiency.Paper at first analyzed the system's C/S mode, and then discussed some kinds of I/O models and server structures of system's communication plat. We analyzed their strongpoints and shortcomings and choiced the IOCP model at last. Paper realized this Teaching-Assisted System in the VC program developing environment by using the Object-Oriented technology. Our program bases on the Client/Server mode, runs in the CAI System Server in TCP/IP network environment and adopts the parallel IOCP server structure. After these, paper researched the network congestion which maybe occur during the period of system running. We put forward the distributed virtual server mechanism to solve this congestion. By agreeing with some protocol between server and client, this mechanism made the server's load to be shared by using the resources of client's host. To do so, we can improve the system's performance and advance service efficiency. After constructed the communication plat, we added the program module of accessing the background database into the service thread. System responses the clients' requests and supplies the clients with service by using the share data in the background database. The background database adopted SQL Server 2000's Relation Database Management System (RDBMS). ODBC (Open Database Connectivity) is SQL Server 2000 Application Program's API (Application Programming Interface). ODBC realized the connection between the program developed in VC environment and SQL Server 2000 Database and the operating to data in database. During the database's designing, paper completed the all...