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Метод тестирования производительности и стресс-тестирования центральных сервисов идентификации облачных систем на примере Openstack Keystone
Труды Института системного программирования РАН. 2015. Т. 27. № 5. С. 49–58.
Nowadays OpenStack platform is a leading solution in cloud computing field. Keystone, the OpenStack Identity Service, is one of its major components. This service is responsible for authentication and authorization of users and services of the system. Keystone is a high-load service since all interactions between services happen through it. This leads us to the following problem: increasing the number of cloud service users results to significant load growth. In this paper we demonstrate the problem of Keystone performance degradation during constant load. In order to find source of the problem we have tested Keystone with different backends (PostgreSQL, MariaDB), frontends (Apache2, ngnix) and keeping the database on different hardware (HDD, SSD and tmpfs on RAM). Using different configuration sets is necessary because it helps us to narrow the amount of possible reasons causing degradation. Tests were conducted with Rally. As a result, in all test cases we have seen inadequate quick degradation under relatively light load. We have also implemented a mock service which represents the simplest Keystone tasks. Our service turned out to be much faster than Keystone. The problem with Keystone might be related to either its internal logic implementation or incorrect interaction with other components; it is the subject of further research.
Гущина В. А., / Series chemrxiv-2023-vpzhz-v2 "ChemRxiv". 2023.
All-inorganic perovskite CsPbBr3 and Cs4PbBr6 nanoparticles are being intensively studied due to their unique properties and wide range of applications; however, however, the nature of their optical properties is not yet fully understood due to the difficulty of synthesis of singlephase nanoparticles. In this article we describe the features of the synthesis of single-phase particles ...
Added: May 14, 2026
Pilé I., Deng Y., Shchur L., / Series arXiv "math". 2026. No. 2604.10254.
We investigate the spatial overlap of successive spin configurations in Markov chain Monte Carlo simulations using the local Metropolis algorithm and the Svendsen-Wang and Wolff cluster algorithms. We examine the dynamics of these algorithms for two models in different universality classes: the Ising model and the Potts model with three components. The overlap of two ...
Added: April 20, 2026
Avdeeva S., Уваров А. Ю., Информатика и образование 2025 Т. 40 № 4 С. 39–49
The ability to work with information is becoming a key success factor in the modern world, and the formation of information and communication competence (IC competence) in the younger generation is one of the most important task of general education. Based on the data obtained during the testing of the IC competence of basic school ...
Added: December 2, 2025
Kagan M., Silkin V. M., Efremov D. V., / Series arXiv "math". 2024. No. 2411.12836.
In this study, we analyze the dielectric function of high-Tc cuprates as a function of doping level, taking into account the full energy band dispersion within the CuO2 monolayer. In addition to the conventional two-dimensional (2D) gapless plasmon mode, our findings reveal the existence of three anomalous branches within the plasmon spectrum. Two of these branches ...
Added: November 27, 2024
Influence of anisotropy on the study of critical behavior of spin models by machine learning methods
Sukhoverkhova D., Shchur L., / Series arXiv "math". 2024. No. 2410.14523.
In this paper, we applied a deep neural network to study the issue of knowledge transferability between statistical mechanics models. The following computer experiment was conducted. A convolutional neural network was trained to solve the problem of binary classification of snapshots of the Ising model's spin configuration on a two-dimensional lattice. During testing, snapshots of ...
Added: October 21, 2024
Mozolenko V., Fadeeva Marina, Shchur L., / Series arXiv "math". 2024. No. 2405.10865.
The development of new algorithms for simulations in physics is as important as the development of new analytical methods. In this paper we present a comparison of the recently developed microcanonical population annealing (MCPA) algorithm with the rather mature Wang-Landau algorithm. The comparison is performed on two cases of the Potts model exhibiting a first ...
Added: May 20, 2024
Kagan M., Аксёнов С. В., / Series Research Square "Research Suqare". 2024. No. 1.
We study different resonances (first of all of the Fano type) in the interference device formed by the Aharonov-Bohm ring with superconducting (SC) wire in the topologically nontrivial state playing a role of a bridge between top and bottom arms. We analyze Majorana modes on the ends of the SC wire and show that the collapse of the ...
Added: April 10, 2024
Ребров Я. В., Glazkov V., Murtazoev A. F. et al., / Series cond-mat "arxiv.org". 2023.
Nabokoite family compounds ACu7(TeO4)(SO4)5Cl (A=Na, K, Cs, Rb) are one of the candidates for the evasive spin-liquid state predicted for highly-frustrated square kagome lattice (SKL). Their magnetic subsystem includes SKL layers decorated by additional copper ions. All members of this family are characterized by quite high Curie-Weiss temperatures (∼80−200 K), but magnetic ordering was reported ...
Added: January 29, 2024
Bartseva K. V., Likhanov M., Soldatova E. L. et al., Образование и наука 2023 Vol. 25 No. 10 P. 183–204
Introduction. Multiple studies advocate an importance of spatial abilities (SA) for
educational and occupational success, especially in STEM. Recently an Online Short Spatial Ability
Battery (OSSAB) was developed and normed for SA testing in adolescents. The battery includes
mechanical reasoning, paper folding, pattern assembly, and shape rotation tests. The battery has shown
good psychometric characteristics (high reliability and validity, ...
Added: December 22, 2023
Tarasov S., Психологическая наука и образование 2023 Т. 28 № 4 С. 63–80
Креативное мышление является важным навыком современного мира, а его оценка с помощью современных цифровых инструментов становится все более сложной методологической задачей. Включение в модель оценки креативного мышления данных о процессе выполнения заданий является перспективным направлением, которое становится возможным в компьютерном тестировании. Применение таких данных позволяет учитывать процессы креативного мышления в динамике, что делает оценку уровня ...
Added: November 13, 2023
Shurakov A., Kaurova N., Belikov I. et al., / Series Physics "arxiv.org". 2022.
In this paper, we report on the method of nondestructive quality control that can be used in fabrication of GaAs high-speed electronics. The method relies on the surface potential mapping and enables rigid in vivo analysis of transport properties of an active electronic device incorporated into a complex integrated circuit. The study is inspired by ...
Added: September 15, 2023
Uglanova I., Tarasov S., Churbanova S. et al., Psychology. Journal of the Higher School of Economics 2025 Vol. 22 No. 2 P. 339–361
Тhe importance of creativе thinking was highlighted in the modern world by including it into the lists of 21st century skills and educational objective into the national curriculums. To make creativity assessment more widespread in school and educational research, it is necessary to diminish the resource-intensity of the assessment for both educators and students. In ...
Added: May 16, 2023
Pugach N., Safonchik M. O., Belotelov V. et al., / Series "cond-mat". 2022. No. 2110.00369.
A detailed investigation of a superconducting spin-triplet valve is presented. This spin-valve consists of a superconducting film covering a metal with an intrinsic spiral magnetic order, which could result from competing isotropic exchanges or, if the crystal lattice breaks central symmetry, from asymmetric Dzyaloshinskii-Moriya exchange. Depending on the anisotropy, such a metal may change its ...
Added: November 16, 2022
Novikov S. V., / Series cond-mat "arxiv.org". 2022. No. 2209.14955.
Charge transport in amorphous semiconductors having spatially correlated exponential density of states (DOS) has been considered for the arbitrary behavior of the correlation function of random energies. Average carrier velocity is exactly calculated for the quasi-equilibrium (nondispersive) transport regime. For the symmetric exponential DOS with exponential tails for low and high energies and non-positive correlation ...
Added: November 1, 2022
Tarasova K., Orel E., Вопросы образования 2022 № 3 С. 187–212
Today critical thinking is one of the key competencies of the modern world. The abundance and availability of various information (in particular due to the spread of electronic devices and the Internet) suggest that people, regardless of age, need to be able to effectively navigate and evaluate information, draw their own conclusions and use arguments ...
Added: October 17, 2022
Avdeeva S., Uvarov A., Tarasova K., Вопросы образования 2022 № 1 С. 218–243
Information and communication literacy is one of the main meta-subject competencies that graduates of the secondary school should possess. The full-fledged formation of this competence is considered as one of the tasks of preparing students for life in the information society and the digital economy. The article discusses the results of a monitoring study of ...
Added: September 6, 2022
Ikhsanov R., Mazur E., Kagan M., / Series "Working papers by Cornell University". 2022. No. 2202.01452.
At present, the task of searching for compounds with a high superconducting transition temperature is a very relevant scientific direction. Usually, the calculation of is carried out by numerically solving the system of Eliashberg equations. In this paper, a set of programs for solving this system written in various forms on the imaginary axis is ...
Added: February 4, 2022
Budkov Y., Zavarzin S., Kolesnikov A. L., Journal of Physical Chemistry C 2021 Vol. 125 No. 38 P. 21151–21159
We formulate a general mean-field theory for a flat electric double layer in ionic liquids and electrolyte solutions with ions possessing static polarizability and a permanent dipole moment on a charged electrode. We establish a new analytical expression for electric double-layer differential capacitance, determining it as an absolute value of the ratio of the local ...
Added: September 16, 2021
Sanina N., Isaeva U., Utenyshev A. et al., Inorganica Chimica Acta 2021 Vol. 527 Article 120559
A new inhibitor of phosphodiesterase (PDE), i.e., nitric oxide (NO) donor, a water soluble DNIC Na[Fe(C7H5N4S)2(NO)2]⋅2.5H2O (1), has been synthesized. The structure of the new complex, its physical-chemical properties in the solid state and in solutions have been studied experimentally (X-ray analysis, IR, UV-Vis, Mossbauer spectroscopy, mass-spectrometry, and amperometry) and theoretically (quantum-chemical modeling by DFT ...
Added: September 16, 2021
Federiakin D., Uglanova I., Skryabin M., Вестник Томского государственного университета 2021 № 465 С. 179–187
Traditionally, psychometrics is concerned with theory-based information about human behavior – indicators of the targeted construct, like item responses, performance assessment products, etc. However, over the past forty years, advances in psychometric modeling and the development of information technologies allowed for the analysis of the so-called collateral information. This information is not theory-based and easy ...
Added: September 1, 2021
Légitimation et disqualification par l’histoire dans les manifestations de rue en Russie (2011-2016)
Архипова А. С., Доронин Д. Ю., Югай Е. Ф. et al., Mouvement Social 2017 No. 3 P. 129–148
This article uses a corpus of more than 6,000 slogans and symbols that include historical references, gathered during street demonstrations in Russia between 2011 and 2016 as part of the collective investigation carried out by the “Contemporary Folklore Monitoring” research group. A quantitative analysis of this corpus reveals the main features of how the past is ...
Added: August 12, 2018
Борисенко О. Д., Пастухов Р. К., С.Д. Кузнецов, Труды Института системного программирования РАН 2016 Т. 28 № 6 С. 111–120
Apache Spark is a framework providing fast computations on Big Data using MapReduce model. With cloud environments Big Data processing becomes more flexible since they allow to create virtual clusters on-demand. One of the most powerful open-source cloud environments is Openstack. The main goal of this project is to provide an ability to create virtual ...
Added: January 25, 2018
S. Kuznetsov, Борисенко О. Д., Алексиянц А. В. et al., Proceedings of the Institute for System Programming of the RAS 2015 Vol. 27 No. 5 P. 35–48
In this paper the problem of creating virtual clusters in clouds for big data analysis with Apache Hadoop and Apache Spark is discussed. Existing methods for Apache Spark clusters creation are described in this work. Also the implemented solution for building Apache Spark clusters and Apache Spark jobs execution in Openstack environment is described. The ...
Added: January 23, 2018
Kuznetsov S. D., Turdakov D. Y., Борисенко О. Д., Труды Института системного программирования РАН 2014 Т. 26 № 4 С. 33–44
This article is dedicated to automation of cluster creation and management for Apache Spark MapReduce implementation in Openstack environments. As a result of this project open-source (Apache 2.0 license) implementation of toolchain for virtual cluster on-demand creation in Openstack environments was presented. The article contains an overview of existing solutions for clustering automation in cloud ...
Added: November 26, 2017