The paper considers a stochastic model of the operation of an automatic information processing system, which is described by a system of differential equations of the Kolmogorov distribution of state probabilities, assuming that the flow of requests is Poisson, including the simplest one. A scheme for solving a system of differential equations of high dimensionality with slowly changing initial data is proposed, and the parameters of the presented model are compared with the parameters of the simulation model of the Apache HTTP Server. To compare the simulation and stochastic models, a test server was used to generate requests and simulate their processing using the Apache JMeter program, which was used to estimate the parameters of the incoming and processed request flows. The presented model does not contradict the simulation model and allows us to evaluate the system's states under different operating conditions and calculate the load on the web server when there is a large amount of data.
Keywords: stochastic modeling, simulation model, Kolmogorov equations, sweep method, queuing system, performance characteristics, test server, request flow, service channels, queue
The simulation model of Apache HTTP Server as a mass service system is considered, the parameters of the corresponding system and Apache HTTP Server are compared using GPSS World environment. The comparison of the simulation model with a real web server is based on the construction of a test server. using Apache JMeter application, which can be used to simulate high load on the server. Query generation and statistics collection was done by Apache JMeter application. A comparison of both reports was given, differences in characteristics were pointed out, and assumptions about the reasons for the differences were outlined. The model can be applied to establish requirements for Apache HTTP Server in order to optimise its performance.
Keywords: simulation modelling, mass service system, efficiency characteristics, test server, flow of requests, service channels, queue