Research And Implementation Of Performance Evaluation Model Of DDS-Based Distributed System

In these key areas of medical, finance and aerospace, computer technology becomes more and more widely used, and in these areas distributed real-time systems are heavily used to assist business, which makes the real-time and flexibility demands of communication among the various subsystems. The communication mode of traditional middleware is too complicate, so it can not meet the requirements of real-time and flexibility. DDS(Data Distribution Service) uses the new publish and subscribe communication model, which solves the real-time and flexibility issues, so DDS is widely used in the distributed real-time systems. At present, the research on DDS is mainly about using DDS to implement the distributed systems, and there are few studies of performance evaluation model of the DDS-based distributed systems. Traditional performance evaluation models of software system have not consider the data publish and subscribe features in DDS-based distributed real-time systems, so these models can not make an accurate assessment of the performance of DDS-based distributed real-time systems.Based on the analysis and research of traditional software system performance evaluation models, and considering the characteristics of DDS-based distributed real-time systems, a performance index system was put forward and the evaluation model of each index was designed in this thesis. The subsystems of the DDS-based distributed systems interact with each other by publishing and subscribing topics, and the components are deployed on multiple computers, According to the characteristics of the hardware and software in the distributed system, factors which should be considered when design the performance index are determined, and the factors include the degree of load balancing, system reliability, the complexity of data communication and factors such as the components resource usage, then the indexes of the performance index system was determined. After determining the indexes, the evaluation model of each index in the performance index system was designed, all the evaluation models considering the number of topics instead of network traffic factor, so the models can consider the characteristics of DDS-based distributed real-time systems. Finally a performance assessment tool on the basis of the performance index system was introduced, and the feasibility and rationality of the performance index system was verified through the experiment, which provided a theoretical basis for the further study.