Component-based Dynamic Updating Of Distributed Software System

Software online evolution technology becomes an important research topic in the field of software maintenance. With advantages such as small grained, cost-effective, low cost flexibility of operation and so on during updating, the dynamic software update technology and update methods become a hot spot of the software online evolution technology.This article research on the architecture and deployment of component-based distributed software system during dynamic updating, also study the management of service dependency in distributed software system. In this article, we propose the two-tier service-oriented model based on OSGi, also use service binder in the model to solve the management of services dependency during dynamic updating.For the advantage in Dynamic availability and substitutability, there are many techniques based on the service orientation model. OSGi is one of those famous techniques. However, OSGi platform is a non-distributed platform. R-OSGi extends the platform of OSGi into the distributed environment. R-OSGi has its disadvantage in the management of remote service and using of network resource. R-OSGi also increases the workload of OSGi platform in the system. Two-tier service–oriented model based on OSGi solves this issue of R-OSGi. In two-tier service–oriented model based on OSGi, every platform would be viewed as a component, which could publish remote service for other platform and also could get remote service from other platform. Through the way of Service-Orient Component model, two-tier service–oriented model based on OSGi solves the difficulty of publishing and getting remote service in the distributed environment. In this paper, we describe the two-tier service–oriented model. We also conclude the differences between this model and R-OSGi,and give the advantages of this model.The Service Binder is a mechanism to automate service dependency management based on OSGi. Service Binder extracts service dependency management logic from the bundles and moves it into an execution environment. This paper discusses the feasibility of using Service Binder the two-tier service-oriented model based on OSGi. In this paper, we give the architecture and implement of two-tier service-oriented model after using the service Binder. This article also gives detail process of the service management, especially the process of remote service dependency.