Study On Dynamic Reliability For Online Software System

With the rapid development of software and information technology, the demandfor the software reliability is increasingly high. The scale and structure of softwaresystems is becoming more and more complex. So the development of software systemhas abandoned the traditional way to start all over again, and largely reuse thecomponents. Therefore, building component-based software reliability models becomeincreasingly important. Currently the component-based software reliability models canbe divided into three classes: state-based model, path-based model and the model basedon component probability migration map. Their principles all depends on using thearchitecture of software system to assess the reliability of the system, which mainlyconsists of components reliability and the transition probability relationship between thecomponents. Once get the information of components, we can use software reliabilitymodels to evaluate the system reliability.But these static models are mostly implemented before the deployment and they arebased on certain invariance assumptions of the operating environment and user needs,just relying on the system design and test technologies is difficult to ensure that it cancover all possible scenarios. In the operational phase real running behavior of softwaresystem is difficult to predict in the development phase, reliability is also hard to getensuring, so the behavior of the software system should be monitored. If at the sametime the architecture and runtime behavior can be known, we can regularly evaluate thesoftware system reliability during the running phase.In this paper, we study on the monitoring of software system during the runningphase, to find the differences of software reliability between testing phase and runningphase. Adjust resources in the software life cycle to ensure the reliability of softwaresystem. This paper proposes a dynamic analysis and maintain system reliabilitymechanism：Firstly, combining static component-based software reliability model and dynamicmonitoring behaviors, so can evaluate the system reliability dynamic during the runningphase.Secondly, pointing out the change trend of system reliability in the operation phase.Gives the risk factors that decrease component reliability and proposes an effectivemethod to reallocate the redundant resources. Finally, the author designs and implements a monitoring system prototype platform.Through the adequate analysis and comparison to experimental data, verifying theeffectiveness of the proposed method.