Performance最新文献

{"title":"Hardware configuration selection through discretizing a continuous variable solution","authors":"R. Wagner, Kishor S. Trivedi","doi":"10.1145/800199.806156","DOIUrl":"https://doi.org/10.1145/800199.806156","url":null,"abstract":"This paper extends a previous model for computer system configuration planning developed by the authors. The problem is to optimally select the CPU speed, the device capacities, and file assignments so as to maximize throughput subject to a fixed cost constraint. We advocate solving this essentially discrete problem in continuous variables followed by an appropriate discretization. The discretization error thus committed is analyzed in detail.","PeriodicalId":32394,"journal":{"name":"Performance","volume":"13 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"1980-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75552911","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Further results on equivalence and decomposition in queueing network models","authors":"A. Brandwajn","doi":"10.1145/800199.806153","DOIUrl":"https://doi.org/10.1145/800199.806153","url":null,"abstract":"This paper addresses three aspects related to the notion of exact equivalence in queueing models. In many cases the parameters of a system equivalent to a given model involve only a small subset of conditional probabilities of the state of the original model given the equivalent one. It is shown that meaningful bounds may be obtained for the conditional probabilities of interest with little computational effort. Such bounds are useful in assessing processing capacities as well as the accuracy of approximate solutions. As a second point it is shown that the notion of exact equivalence may be easily extended to networks with non-exponential servers. This is done for both the methods of supplementary variables and for the imbedded Markov chain technique. Qualitative analysis of approximation methods is also discussed. Finally, numerical methods based on the notion of exact equivalence, i.e. operating on conditional probabilities, are considered.","PeriodicalId":32394,"journal":{"name":"Performance","volume":"28 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"1980-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84082396","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Computer capacity planning using queueing network models","authors":"T. Lo","doi":"10.1145/800199.806158","DOIUrl":"https://doi.org/10.1145/800199.806158","url":null,"abstract":"This paper presents several computer capacity planning case studies using a modeling tool, BEST/1, derived from the theory of queueing networks. All performance predictions were evaluated based on the selected service levels such as response times and throughputs. Advantages and disadvantages of using the modeling approach are also briefly discussed.","PeriodicalId":32394,"journal":{"name":"Performance","volume":"65 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"1980-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74101059","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"XRAY: Instrumentation for multiple computers","authors":"Russ Blake","doi":"10.1145/800199.806146","DOIUrl":"https://doi.org/10.1145/800199.806146","url":null,"abstract":"XRAY presents a global view of the performance of hardware and software components on multiple, distributed computers. The set of components chosen for measurement can be changed at any time throughout a network of systems, and can be selected to minimize data collection time and measurement space. In the course of normal activities the operating system executes firmware which increments counters for the measured components. Periodically, the counters are recorded in an ordinary file by a process in each processor. An analysis program permits browsing through components and plotting counters in real time. Analysis focuses on detecting the distributed sources of excessive activity.","PeriodicalId":32394,"journal":{"name":"Performance","volume":"27 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"1980-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84231299","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The response of job classes with distinct policy functions(Extended Abstract)","authors":"M. Ruschitzka","doi":"10.1145/1009375.806172","DOIUrl":"https://doi.org/10.1145/1009375.806172","url":null,"abstract":"Policy function schedulers provide a flexible framework for implementing a wide range of different scheduling schemes. In such schedulers, the priority of a job at any instant in time is defined by the difference between the time it spent in the system and an arbitrary function of its attained service time. The latter is called the policy function and acts as the functional parameter that specifies a particular scheduling scheme. For instance, a constant policy function specifies the first-come, first-serve scheduling scheme. By changing the policy function, the system behavior can be adjusted to better conform with desired response characteristics. It is common to express response characteristics in terms of a response function, the average response time of a job conditioned on its service requirement in equilibrium. In this paper, we analyze processor-sharing M/G/1 systems in which the priorities of different classes of jobs are determined by distinct policy functions.","PeriodicalId":32394,"journal":{"name":"Performance","volume":"13 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"1980-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87202047","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Performance evaluation of a feedback data flow processor using simulation","authors":"C. Dhas","doi":"10.1145/800199.806163","DOIUrl":"https://doi.org/10.1145/800199.806163","url":null,"abstract":"This paper presents a method to estimate the performance of a feedback data flow processor using software simulation. A brief over view of a data flow language and a data flow processor along with the conceptual view of a software simulator are described. Numerical measurements of parallelism and resources requirements are obtained by translating high level language programs to data flow language and then executing them on the simulator.","PeriodicalId":32394,"journal":{"name":"Performance","volume":"71 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"1980-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76460818","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The impact of certain parameter estimation errors in queueing network models","authors":"K. D. Gordon, L. Dowdy","doi":"10.1145/800199.806145","DOIUrl":"https://doi.org/10.1145/800199.806145","url":null,"abstract":"The effect that parameter estimation errors have on performance in closed product form queueing networks is investigated. In particular, the effects of errors in the relative utilization estimates of the servers are analyzed. It is shown that in single class load independent networks, the resulting errors in throughput and utilizations are of approximately the same percentage as the errors in the relative utilization estimates. This result does not hold in networks with load dependent servers or multiple customer classes. The percentage errors in mean queue length depend upon the degree of multiprogramming in the network. Errors in mean queue lengths can become unbounded as the degree of multiprogramming becomes unbounded. Implications of these results to computer system modeling are discussed.","PeriodicalId":32394,"journal":{"name":"Performance","volume":"41 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"1980-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77659760","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimal replication of parallel-read, sequential-write systems","authors":"E. Coffman, E. Gelenbe, R. Wood","doi":"10.1145/800199.806165","DOIUrl":"https://doi.org/10.1145/800199.806165","url":null,"abstract":"Frequently used computer elements that can be written by at most one process at a time constitute important bottlenecks in multiprocessor system operation, particularly when such elements are accessible only serially. Hardware devices, data files, system tables and critical sections in general may be examples of such elements. One common way to relieve this congestion is to provide several copies of the element, which can then be read (used) in parallel. However, the requirement that writing (changing) remain sequential means that writing times increase with the number of copies provided. The optimization question in this trade-off is the main concern of this paper. A probability model of such a system is formulated with the objective of obtaining read-rate capacities as a function of read/write loads and the number of copies provided. The above optimization problem is expressed in terms of these results and then solved. In particular, it is shown how to select the number of copies that maximizes the read-rate capacity for given system parameters. Two distinct operating regimes, based on how interrupted read operations are restarted, are analyzed.","PeriodicalId":32394,"journal":{"name":"Performance","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"1980-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82475434","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A model of shared dasd and multipathing","authors":"Y. Bard","doi":"10.1145/800199.806157","DOIUrl":"https://doi.org/10.1145/800199.806157","url":null,"abstract":"This paper presents a model of an I/O subsystem in which devices can be accessed from multiple CPUs and/or via alternative channel and control unit paths. The model estimates access response times, given access rates for all CPU-device combinations. The systems treated are those having the IBM System/370 architecture, with each path consisting of a CPU, channel, control unit, head of string, and device with rotational position sensing. The path selected for an access at seek initiation time remains in effect for the entire channel program. The computation proceeds in three stages: First, the feasibility of the prescribed access rates is determined by solving a linear programming problem. Second, the splitting of access rates among the available paths is determined so as to satisfy the following principle: The probability of selecting a given path is proportional to the probability that the path is free. This condition leads to a set of nonlinear equations, which can be solved by means of the Newton-Raphson method. Third, the RPS hit probability, i.e. the probability that the path is free when the device is ready to transmit, is computed in the following manner: From the point of view of the selected path, the system may be viewed as being in one of 25 possible states. There are twelve different subsets of states whose aggregate probabilities can be computed from the (by now) known flow rates over the various paths. The maximum entropy principle is used to calculate the unknown state probabilities, with the known aggregate probabilities acting as constraints. The required RPS hit probability can be computed easily once the state probabilities have been determined. Explicit formulas are given for all these quantities. Empirically derived formulas are used to compute the RPS miss probability on subsequent revolutions, given the probability on the first revolution. The model is validated against a simulator, showing excellent agreement for systems with path utilizations up to 50 percent. The model is also validated against measurements from a real three-CPU system with 31 shared devices. In this validation, the I/O subsystem model acts as a common submodel to three copies of a system model, one for each CPU. Estimated end-user transaction response times show excellent agreement with the live measurements.","PeriodicalId":32394,"journal":{"name":"Performance","volume":"150 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"1980-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86137366","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Performance evaluation and prediction of storage hierarchies","authors":"A. Lehmann","doi":"10.1145/800199.806149","DOIUrl":"https://doi.org/10.1145/800199.806149","url":null,"abstract":"This paper proposes a modelling methodology combining simulation and analysis for computer performance evaluation and prediction. The methodology is based on a special workload model that is suitable for the generation and description of dynamic program behaviour. A description of this workload model is given in section 2. The applicability of this concept with respect to the design of new storage systems, as well as the improvement or comparison of existing systems, will be described by investigation of the efficiency of small cache memories in section 3.","PeriodicalId":32394,"journal":{"name":"Performance","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"1980-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84087892","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}