Research On Distributed Pi Calculus Based On P2P Network

In recent years, with the rapidly increasing in network scale, centralized processing mode of the central system load is too large, leading to traffic jams and paralysis of the network caused by a single point of failure. The distributed technology has the advantage of high reliability and diversion, so it has gradually replaced the traditional centralized processing model, which becomes a hot topic in today’s information technology. The nature of distributed network system is solving the problem of resource management, including how to store the resources and how to access to the resources. So it is important to consider the representation manner of resources for the research on underlying calculation model of the distributed system.Pi calculus is a process calculus with algebraic properties, which is used for formalization analysis and description on the various areas of the system modeling. The resources of distributed system can be expressed by the concept of name in Pi calculus. Pi calculus can also model the dynamic changes of the network topology combined with its mobility property. However, when specific examples are modeled, the fundamental Pi calculus can cause the established model complexly because of the lack of direct control structure, description of complex data types and even sometimes using higher order Pi calculus. So, researchers improve the Pi calculus to accommodate the formalization analysis of different areas of models. Based on the research of the distributed “peer to peer” network, Pi calculus and its variants of Dpi calculus, the paper proposed the NPi calculus that is a more realistic network topology. The NPi calculus can describe the distributed network system, which has practical application significance. Details are as follows:1. On the basis of Pi calculus, the paper proposed a calculus that was closer to the real distributed network topology, namely NPi calculus. Then, the paper gave the syntax and semantics of the extended calculus, structural congruence, as well as the reaction rules. Finally, according to the new label migration system the paper defined, the bisimulation theory analysis and proof of the NPi calculus were given.2. Using the NPi calculus to model and analyze the P2 P network model--Pastry and simple DHT, the paper verified the expression abilities of NPi calculus.3. Using the Pict programming language to implement the established formal model of Pastry, the paper verified the correctness of the model established by the NPi calculus.4. Many sets of comparative experiments of Pict language against C language have been given on Linux environment, which are based on the P2 P model of NPi calculus implemented. The paper compared the efficiency of three angles from real time, sys time and user time. It indicated that the Pict language had an advantage of efficiency for achieving the distributed network model.Combining the work of the paper, it can be obtained: for the underlying model of a distributed network, NPi calculus have strong expression ability, and Pict can achieve it with higher efficiency, which provide experimental basis for the research on Pi Calculus in underlying model of distributed system.