Based On The Pulse Communication Model Of Scheduling N

According to IDC, the trend of application for database at high level goes ahead with demand of "high performance, high reliability, high security and huge storage". Meanwhile, application field also needs database products to provide users with higher performance and higher reliability. By right of its inherent features and design goal, distributed and parallel database management system (DPDBMS) meets the trend of demand. To obtain high performance in the DPDBMS, this thesis, as viewed from that communication subsystem ought to properly make use of system resource, introduces dynamic scheduling strategy into the research of improving communication performance and brings forward new communication model based on scheduling. The model, according to current status of system, could dynamically calculate the most suitable system resource ratio of communication subsystem, then decides whether to get or free some system resource. In this way, not only performance bottleneck within communication subsystem could be overcome, but also couldn't result in making external processing ability of DPDBMS become new bottleneck. As a result, high performance is gained successfully. To obtain high reliability, that is, DPDBMS could detect sites in failure status in time and provide auto recovery function while confronted with system failure. This thesis proposes n Dimension Pulsing Communication Model (nDPCM) which turns all sites in DPDMS into one ring by combining distributed method with logical ring, and adopts non-block TCP to finish distributed asynchronous pulsing process. In this way, high reliability is achieved successfully. Combining communication model based on scheduling with n Dimension Pulsing Communication Model, the n Dimension Pulsing Communication Model Based on Scheduling (nDPCMBS) is proposed and implemented in DPSQL (a kind of distributed and parallel database management system). Test result shows that nDPCMBS is an effective way in improving performance and reliability of DPSQL. This thesis contains four chapters as a whole. In chapter 1, various techniques of improving communication performance are reviewed. In chapter 2, DPDBMS, DPSQL and their features are discussed. In chapter 3, nDPCMBS and its implementation are discussed in detail. In chapter 4, both performance analysis on...