Performance Evaluation最新文献

{"title":"Can attacks reduce Age of Information?","authors":"Josu Doncel ,&nbsp;Mohamad Assaad","doi":"10.1016/j.peva.2025.102498","DOIUrl":"10.1016/j.peva.2025.102498","url":null,"abstract":"<div><div>We study a monitoring system in which a single source sends status updates to a monitor through a communication channel. The communication channel is modeled as a queueing system, and we assume that attacks occur following a random process. When an attack occurs, all packets in the queueing system are discarded. While one might expect attacks to always negatively impact system performance, we demonstrate in this paper that, from the perspective of Age of Information (AoI), attacks can in some cases reduce the AoI. Our objective is to identify the conditions under which AoI is reduced and to determine the attack rate that minimizes or reduces AoI. First, we analyze single and tandem M/M/1/1 queues with preemption and show that attacks cannot reduce AoI in these cases. Next, we examine a single M/M/1/1 queue without preemption and establish necessary and sufficient conditions for the existence of an attack rate that minimizes AoI. For this scenario, we also derive an upper bound for the optimal attack rate and prove that it becomes tight when the arrival rate of updates is very high. Through numerical experiments, we observe that attacks can reduce AoI in tandem M/M/1/1 queues without preemption, as well as in preemptive M/M/1/2 and M/M/1/3 queues. Furthermore, we show that the benefit of attacks on AoI increases with the buffer size.</div></div>","PeriodicalId":19964,"journal":{"name":"Performance Evaluation","volume":"169 ","pages":"Article 102498"},"PeriodicalIF":1.0,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144196352","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Discrete Bayesian Optimization via Machine Learning","authors":"Roberto Sala,&nbsp;Bruno Guindani,&nbsp;Danilo Ardagna,&nbsp;Alessandra Guglielmi","doi":"10.1016/j.peva.2025.102487","DOIUrl":"10.1016/j.peva.2025.102487","url":null,"abstract":"<div><div>Bayesian Optimization (BO) is a family of powerful algorithms designed to solve complex optimization problems involving expensive black-box functions. These sequential algorithms iteratively update a surrogate model of the objective function (OF), effectively balancing exploration and exploitation to identify near-optimal solutions within a limited number of iterations. Originally designed for continuous, unconstrained domains, its efficiency has inspired adaptations for discrete, constrained optimization problems. On the other hand, Machine Learning (ML) models allow accurate predictions for black-box functions, although they typically require large amounts of data for training. Leveraging the strengths of BO and ML, research tackles the challenge of identifying optimal configurations in the context of cloud computing. This paradigm has become pervasive due to its ability to provide flexible and scalable resources. Identifying the optimal hardware-software configuration is essential for minimizing costs while meeting Quality of Service constraints. This task involves solving complex optimization problems over multidimensional discrete domains and black-box objective functions and constraints, within a limited number of iterations. To address this challenge, this work introduces <em>d-MALIBOO</em>, a BO-based algorithm that integrates ML techniques to enhance the efficiency of finding near-optimal solutions in discrete and bounded domains. While BO builds the surrogate model of the OF, ML models determine the feasible region of the black-box constraints and guide the BO algorithm toward promising regions of the discrete domain. Furthermore, we introduce an <span><math><mi>ɛ</mi></math></span>-greedy approach to favor exploration in domains with multiple local optima. Experimental results show that our algorithm outperforms OpenTuner, a popular framework for constrained optimization, by reducing the average regret by 29%, and SVM-CBO, a BO-based algorithm that integrates SVM models to determine the feasible region, by 82%.</div></div>","PeriodicalId":19964,"journal":{"name":"Performance Evaluation","volume":"169 ","pages":"Article 102487"},"PeriodicalIF":1.0,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144134308","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimizing latency for caching with delayed hits in non-stationary environment","authors":"Bowen Jiang,&nbsp;Yubo Yang,&nbsp;Bo Jiang","doi":"10.1016/j.peva.2025.102488","DOIUrl":"10.1016/j.peva.2025.102488","url":null,"abstract":"<div><div>Caching plays a crucial role in many latency-sensitive systems, including content delivery networks, edge computing, and microprocessors. As the ratio between system throughput and transmission latency increases, delayed hits in cache problems become more prominent. In real-world scenarios, object access patterns often exhibit a non-stationary nature. In this paper, we investigate the latency optimization problem for caching with delayed hits in a non-stationary environment, where object sizes and fetching latencies are both non-uniform. We first find that given known future arrivals, evicting the object with the larger size, a higher aggregate delay due to miss and arriving the farthest in the future brings more gains in reducing latency. Following our findings, we design an online learning framework to make cache decisions more effectively. The first component of this framework utilizes historical data within the training window to estimate the object’s non-stationary arrival process, modeled as a mixture of log-gaussian distributions. Subsequently, we predict future arrivals based on this estimated distribution. According to these predicted future arrivals, we can determine the priority of eviction candidates using our defined rank function. Experimental results on four real-world traces show that our algorithm consistently reduces latency by <span><math><mrow><mn>2</mn><mtext>%</mtext><mo>−</mo><mn>10</mn><mtext>%</mtext></mrow></math></span> on average compared to state-of-the-art algorithms.</div></div>","PeriodicalId":19964,"journal":{"name":"Performance Evaluation","volume":"169 ","pages":"Article 102488"},"PeriodicalIF":1.0,"publicationDate":"2025-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144124925","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Multiserver Job Queuing Model with two job classes and Cox-2 service times","authors":"Adityo Anggraito ,&nbsp;Diletta Olliaro ,&nbsp;Andrea Marin ,&nbsp;Marco Ajmone Marsan","doi":"10.1016/j.peva.2025.102486","DOIUrl":"10.1016/j.peva.2025.102486","url":null,"abstract":"<div><div>Datacenters comprise a variety of resources (processors, memory, input/output modules, etc.) that are shared among requests for the execution of computing jobs submitted by datacenter users. Jobs differ in their frequency of arrivals, demand for resources, and execution times. Resource sharing generates contention, especially in heavily loaded systems, that must therefore implement effective scheduling policies for incoming jobs. The First-In First-Out (FIFO) policy is often used for batch jobs, but may produce under-utilization of resources, in terms of wasted servers. This is due to the fact that a job that requires many resources can block jobs arriving later that could be served because they require fewer resources. The mathematical construct often used to study this problem is the Multiserver Job Queuing Model (MJQM), where servers represent resources which are requested and used by jobs in different quantities. Unfortunately, very few explicit results are known for the MJQM, especially at realistic system loads (i.e., before saturation), and hardly any considers the case of non-exponential service time distributions. In this paper, we propose the first exact analytical model of the non-saturated MJQM in case of two classes of customers with service times having 2-phase Coxian distribution. Our analysis is based on the matrix geometric method. Our results provide insight into datacenter dynamics, thus supporting the design of more complex schedulers, capable of improving performance and energy consumption within large datacenters.</div></div>","PeriodicalId":19964,"journal":{"name":"Performance Evaluation","volume":"169 ","pages":"Article 102486"},"PeriodicalIF":1.0,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144131426","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Controller synthesis in timed Büchi automata: Robustness and punctual guards","authors":"Benoît Barbot ,&nbsp;Damien Busatto-Gaston ,&nbsp;Catalin Dima ,&nbsp;Youssouf Oualhadj","doi":"10.1016/j.peva.2025.102483","DOIUrl":"10.1016/j.peva.2025.102483","url":null,"abstract":"<div><div>We consider the synthesis problem on timed automata with Büchi objectives, where delay choices made by a controller are subjected to small perturbations. Usually, the controller needs to avoid punctual guards, such as testing the equality of a clock to a constant. In this work, we generalize to a robustness setting that allows for punctual transitions in the automaton to be taken by controller with no perturbation. In order to characterize cycles that resist perturbations in our setting, we introduce a new structural requirement on the reachability relation along an accepting cycle of the automaton. This property is formulated on the region abstraction, and generalizes the existing characterization of winning cycles in the absence of punctual guards. We show that the problem remains within <span><math><mi>PSPACE</mi></math></span> despite the presence of punctual guards.</div></div>","PeriodicalId":19964,"journal":{"name":"Performance Evaluation","volume":"168 ","pages":"Article 102483"},"PeriodicalIF":1.0,"publicationDate":"2025-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143816244","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A generalized result for the discrete-time two-queue randomly alternating service system","authors":"Herwig Bruneel,&nbsp;Arnaud Devos,&nbsp;Joris Walraevens","doi":"10.1016/j.peva.2025.102484","DOIUrl":"10.1016/j.peva.2025.102484","url":null,"abstract":"<div><div>In this paper, we revisit the discrete-time two-queue <em>randomly alternating service</em> system, where one common server is shared by two queues by allocating the server, independently from slot to slot, with fixed probabilities to either queue. Arrivals of new customers into the two-queue system occur independently from slot to slot, but may be mutually dependent within a slot. They are characterized by the joint probability generating function (<em>pgf</em>) <span><math><mrow><mi>A</mi><mrow><mo>(</mo><msub><mrow><mi>z</mi></mrow><mrow><mn>1</mn></mrow></msub><mo>,</mo><msub><mrow><mi>z</mi></mrow><mrow><mn>2</mn></mrow></msub><mo>)</mo></mrow></mrow></math></span> of the numbers of arrivals in both queues during one time slot. The service times of all customers are equal to exactly one time slot.</div><div>We extend various existing results with respect to the queueing behavior of this system. Specifically, we show that the <em>exact</em> solutions that were previously found for the steady-state joint pgf <span><math><mrow><mi>U</mi><mrow><mo>(</mo><msub><mrow><mi>z</mi></mrow><mrow><mn>1</mn></mrow></msub><mo>,</mo><msub><mrow><mi>z</mi></mrow><mrow><mn>2</mn></mrow></msub><mo>)</mo></mrow></mrow></math></span> of the system contents in both queues for the scenarios of <em>independent Bernoulli</em> arrivals, <em>identical Bernoulli</em> arrivals, <em>global geometric</em> arrivals, <em>global geometric group</em> arrivals, and the superposition of <em>identical Bernoulli</em> arrivals and <em>global geometric (group)</em> arrivals, are all special cases of a more general result, which is valid for a whole class of arrival pgfs <span><math><mrow><mi>A</mi><mrow><mo>(</mo><msub><mrow><mi>z</mi></mrow><mrow><mn>1</mn></mrow></msub><mo>,</mo><msub><mrow><mi>z</mi></mrow><mrow><mn>2</mn></mrow></msub><mo>)</mo></mrow></mrow></math></span> that (among others) encompasses the aforementioned specific arrival scenarios. However, the defined class is much broader than this, and our new result allows the solution for entirely new arrival pgfs as well. We illustrate this abundantly with a large number of detailed examples. The proof of the general result is a mainly <em>algebraic</em> one and, unlike earlier studies, does not require intricate techniques from complex-function analysis.</div></div>","PeriodicalId":19964,"journal":{"name":"Performance Evaluation","volume":"168 ","pages":"Article 102484"},"PeriodicalIF":1.0,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143785629","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Editorial: Special issue on timed and stochastic approaches to system evaluation: Selected papers from QESTFORMATS 2024","authors":"","doi":"10.1016/j.peva.2025.102485","DOIUrl":"10.1016/j.peva.2025.102485","url":null,"abstract":"","PeriodicalId":19964,"journal":{"name":"Performance Evaluation","volume":"168 ","pages":"Article 102485"},"PeriodicalIF":1.0,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143816243","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Certificates and witnesses for multi-objective queries in Markov decision processes","authors":"Christel Baier,&nbsp;Calvin Chau,&nbsp;Sascha Klüppelholz","doi":"10.1016/j.peva.2025.102482","DOIUrl":"10.1016/j.peva.2025.102482","url":null,"abstract":"<div><div>Probabilistic model checking is a technique for formally verifying the correctness of probabilistic systems w.r.t. given specifications. Typically, a model checking procedure outputs whether a specification is satisfied or not, but does not provide additional insights on the correctness of the result, thereby diminishing the trustworthiness and understandability of the verification process. In this work, we consider certifying verification algorithms that also provide an independently checkable certificate and witness in addition to the verification result. The certificate can be used to easily validate the correctness of the result and the witness provides useful diagnostic information, e.g. for debugging purposes. More specifically, we study certificates and witnesses for specifications in the form of <em>multi-objective</em> queries in Markov decision processes. We first consider multi-objective reachability and invariant queries and then extend our techniques to mean-payoff expectation and mean-payoff percentile queries. Thereby, we generalize previous works on certificates and witnesses for single reachability and invariant constraints. In essence, we derive certifying verification algorithms from known linear programming techniques and show that witnesses, both in the form of schedulers and subsystems, can be obtained from the certificates. As a proof-of-concept, we report on an implementation of our certifying verification algorithms and present experimental results, demonstrating the applicability on moderately-sized case studies.</div></div>","PeriodicalId":19964,"journal":{"name":"Performance Evaluation","volume":"168 ","pages":"Article 102482"},"PeriodicalIF":1.0,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143748192","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimizing spatial modulation MIMO IoT systems with full-duplex/half-duplex UAVs and enhanced transmit antenna selection","authors":"Bao The Phung ,&nbsp;Ba Cao Nguyen ,&nbsp;Nguyen Van Vinh ,&nbsp;Bui Vu Minh ,&nbsp;Nguyen Huu Khanh Nhan","doi":"10.1016/j.peva.2025.102481","DOIUrl":"10.1016/j.peva.2025.102481","url":null,"abstract":"<div><div>Multiple-input multiple-output (MIMO) systems play a crucial role in elevating the efficiency and reliability of communication networks, especially within Internet of Things (IoT) applications. This article introduces a novel approach involving full-duplex (FD) and half-duplex (HD) relays mounted on unmanned aerial vehicles (UAVs) to enhance MIMO systems. Incorporating spatial modulation (SM) and transmit antenna selection (TAS) techniques aims to optimize system performance while reducing computational complexity to meet IoT requirements. The article mathematically formulates outage probabilities (OPs) and system throughputs (STs) for the proposed MIMO-IoT-UAV systems utilizing SM with FD/HD-UAV, both with and without TAS, over practical Nakagami-<span><math><mi>m</mi></math></span> channels. Numerical illustrations underscore the advantages of employing FD/HD-UAV and TAS in MIMO-IoT-UAV systems. Specifically, OPs with TAS are significantly lower, while STs with TAS are notably higher than their counterparts without TAS. Additionally, TAS with FD-UAV yields greater benefits than HD-UAV, particularly in preventing the error floor associated with residual self-interference (RSI). To mitigate this error floor in MIMO-IoT-UAV systems using FD-UAV, an effective strategy involves increasing the number of transmit/receive antennas. The choice between FD and HD modes hinges on parameters such as transmit power, data rate, and RSI. Depending on these factors, FD-UAV performance may exhibit lower or higher error rates than HD-UAV. Hence, the optimal selection of FD or HD mode, combined with TAS, is essential for enhancing MIMO-IoT-UAV system performance. This optimization process should consider parameters like RSI level, the number of transmit/receive antennas, data rate requirements, and UAV position to ensure efficient and reliable communication across diverse scenarios.</div></div>","PeriodicalId":19964,"journal":{"name":"Performance Evaluation","volume":"168 ","pages":"Article 102481"},"PeriodicalIF":1.0,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143642833","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Approximation of cumulative distribution functions by Bernstein phase-type distributions","authors":"András Horváth ,&nbsp;Illés Horváth ,&nbsp;Marco Paolieri ,&nbsp;Miklós Telek ,&nbsp;Enrico Vicario","doi":"10.1016/j.peva.2025.102480","DOIUrl":"10.1016/j.peva.2025.102480","url":null,"abstract":"<div><div>The inclusion of generally distributed random variables in stochastic models is often tackled by choosing a parametric family of distributions and applying fitting algorithms to find appropriate parameters. A recent paper proposed the approximation of probability density functions (PDFs) by Bernstein exponentials, which are obtained from Bernstein polynomials by a change of variable and result in a particular case of acyclic phase-type distributions. In this paper, we show that this approximation can also be applied to cumulative distribution functions (CDFs), which enjoys advantageous properties and achieves similar accuracy; by focusing on CDFs, we propose an approach to obtain stochastically ordered approximations. The use of a scaling parameter in the approximation is also presented, evaluating its effect on approximation accuracy.</div></div>","PeriodicalId":19964,"journal":{"name":"Performance Evaluation","volume":"168 ","pages":"Article 102480"},"PeriodicalIF":1.0,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143628836","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}