This article describes a software complex simulation, which allows you to evaluate the impact of the main integrated indicators of the distributed information processing system on its reactivity, taking into account the properties of self-similarity of traffic, TCP/IP data transfer Protocol, and various architectures. The software package consists of software-implemented mathematical models of distributed information processing systems based on file-server, two-level client-server and three-level client-server architecture, as well as the algorithm of distributed information processing system objects distribution. The platform AnyLogic PLE was used as a software tool.

Keywords: a distributed information processing system architecture "file-server", two-tier architecture "client-server", three-tier architecture "client-server", simulation, self-similar traffic, agent-based modeling, discrete event simulation, system dynamics

In this article, using the decomposition approximation based on Norton's theorem, the authors present a mathematical model of the distributed information processing system based on the local computer network on file-server architecture with arbitrary functions of the distribution of service time of requests in the network nodes. A conceptual model of an equivalent two-node Queuing network is constructed, in which the first center of the network coincides with the i-th center of the original network with an arbitrary law of distribution of the duration of requests maintenance, and the second (composite), which is the equivalent of the rest of the network, has exponentially distributed service time, which depends on the number of messages in it. The basic mathematical expressions for calculating the intensity of service in the composition center, as well as expressions for calculating the average response time of the system to user requests are also presented.

Keywords: distributed information processing system, file-server architecture, decomposition approximation, queueing network, compositional center, intensity of service, the average response time of the system to user requests, conceptual model, normalizing constan

This article describes a software package to solve the problem of optimal placement of information resources-fragments of a distributed database on the nodes of a distributed economic information system by the criterion of the minimum average response time of the system to user requests. The software complex consists of software-implemented mathematical models of distributed systems of processing economic information on the basis of file-server, two-level client-server and three-level client-server architecture, as well as optimization algorithm. The developed software product also allows to make experiments for obtaining and subsequent analysis of the dependence of the reactivity of distributed systems on such integral characteristics as the dimension of the problem, the intensity of the formation of requests by users, the speed of message transmission through communication channels, the speed of reading, the speed of writing and processing in the nodes, which allows to implement a more rational organization of the computational process in the system. The software was implemented in C#, the NetFramework 4.6.1 platform, using the Microsoft Visual Studio 2017 Community development environment.

Keywords: economic information system, distributed information processing system, architecture "file-server", two-level architecture "client-server" three-level architecture "client-server", the global balance equation, a closed exponential queueing network