文章基本信息

标题：Assessment of performance of a distributed information system based on time profile
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作者：Vitalii Savchenko ; Oleksander Matsko ; Viktoria Vorobiova 等
期刊名称：Eastern-European Journal of Enterprise Technologies
印刷版ISSN：1729-3774
电子版ISSN：1729-4061
出版年度：2017
卷号：6
期号：2
页码：44-52
DOI：10.15587/1729-4061.2017.116019
语种：English
出版社：PC Technology Center
摘要：The problem of determining performance parameters for distributed information systems, which are formed by heterogeneous hardware, is examined. The information system, designed to perform distributed computing, based on the interaction between elements, is presented in the form of a combination of operation processes of software objects (agents) in interaction with operators.To provide a possibility of algorithmic and quantitative analysis of the system’s operation process, the authors used time diagrams, which can be obtained based of time profiles of serial and distributed actors. Construction of the time profile of an actor is provided by knowledge of the sequence of performed actions and the average time to perform each action. Based on the knowledge of a typical time profile, estimations of different kinds of performance were obtained and the ratio, linking the main forms of performance to a variety of quantitative characteristics of the system, was derived.As the key indicator of performance assessment, it is proposed to apply throughput, which for a serial actor is the ratio of loading of an actor and total time of actions per task. It was shown that within a single distributed actor, total throughput remains constant regardless of redistribution of the number of tasks between serial actors.As another performance indicator, it is proposed to apply response time of the system as the average time to fulfil a task by an actor. Relationship between response time and throughput of the system was established analytically. It was determined by modeling that at an increase in throughput, response time of the system decreases, reaching 0 at a certain ratio of throughput and the number of fulfilled tasks.The introduction of these ratios, in addition to the key indicators, also makes it possible to determine derivative parameters of the system, such as minimal computation time, average time of waiting for requests and amount of memory, required to fulfil tasks. In this case, it was determined that the minimum computation time is a magnitude, dependent on the capacity of an actor and the number of actions performed, as well as the ratio of computation time and exchange time. The average time of waiting for a request is the difference between total operation time and direct time for fulfilling the task by actors. The amount of required memory is determined based on knowledge of amount of memory, involved in performance of certain processes and atomic operations.Presented ratios make it possible to evaluate quantitatively parameters of distributed information systems and to synthesize systems with assigned parameters of throughput and response time.
关键词：distributed information system;time profile;serial actor;throughput capacity;system response time