The Research Of Routing Based On Event Space Partition And Filtering Of Publish/Subscribe And Network Reconfiguration

The rapid development and widely application of Internet greatly changes the scale of distributed system,which makes traditional point-to-point synchronous communication unable to meet dynamic application environment.Publish/subscribe system reflects the nature of asynchrony,many-to-many communications and dynamics,which is the extensive use of communication model in large-scale dynamic distributed environment.Compared with the traditional communication model,the participants of event-based interaction model are completely decoupled in terms of time,space,synchronization,which well adapt to the distributed system applications.So publish/subscribe system has broad application prospects.The routing is one of essential issues of publish/subscribe system.Because most systems are hierarchical topology and use a simple routing,which are not suitable for large-scale applications.In the analysis of publish/subscribe model,classification and characteristics,the existing routing algorithms are improved.For routing optimization and routing maintenance,network reconfiguration is proposed and the technologies related to their implenents are discussed.The major research results are as follows:1) To solve the shortcomings of existing routing algorithm,such as overload and inefficience of system,ESPF routing algorithm is presented in this paper,which is based on mechanism of event space partition and filter merging.The partition of event space makes events routing within a smaller scope,the advantage of which is that it needn't establish subscription status by flooding and improves the scalability and efficiency of the system.The application of filter merging reduces the size of routing table and greatly improves the performance of the system.2) In the study of network reconfiguration,it focuses on routing optimization and maintenance.In the view of routing optimization, reconfiguration algorithm is proposed,which is based on correlation of the subscriptions.According to the similarity of interested subscription,TCP connections between the agents are added or removed,topology of network is dynamically adjustment,the distance between the agents with similarly subscription is reduced,and the numbers of transponder nodes are effectively reduced.In the view of routing maintenance,when the equipment or links are failure,publish/subscribe system with fault-tolerant ability can solve the problem timely,and restore normal communication,so as to ensure network reliability and security of the network to maximize.3) The ESPF routing algorithm and network reconfiguration proposed in this paper are tested in the network simulation software NS2.In comparison with the traditional routing,the results show that ESPF routing algorithm significantly reduces the load of the system,and the network reconfiguration not only optimizes routing,reduces the number of transmit filters,improves the efficiency of the system,but also makes the system a certain degree of fault tolerance.