Major Trends in Operating Systems Development

Operating systems have changed in nature in response to demands of users, and in response to advances in hardware and software technology. The purpose of this paper is to trace the development of major themes in operating system design from their beginnings through the present. This is not an exhaustive history of operating systems, but instead is intended to give the reader the flavor of the dif ferent periods in operating systems\u27 development. To this end, the paper will be organized by topic in approximate order of development. Each chapter will start with an introduction to the factors behind the rise of the period. This will be fol lowed by a survey of the state-of-the-art systems, and the conditions influencing them. The chapters close with a summation of the significant hardware and software contributions from the period

An efficient virtual network interface in the FUGU scalable workstation dc by Kenneth Martin Mackenzie.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1998.Includes bibliographical references (p. 123-129).Ph.D

EOS: A project to investigate the design and construction of real-time distributed embedded operating systems

The EOS project is investigating the design and construction of a family of real-time distributed embedded operating systems for reliable, distributed aerospace applications. Using the real-time programming techniques developed in co-operation with NASA in earlier research, the project staff is building a kernel for a multiple processor networked system. The first six months of the grant included a study of scheduling in an object-oriented system, the design philosophy of the kernel, and the architectural overview of the operating system. In this report, the operating system and kernel concepts are described. An environment for the experiments has been built and several of the key concepts of the system have been prototyped. The kernel and operating system is intended to support future experimental studies in multiprocessing, load-balancing, routing, software fault-tolerance, distributed data base design, and real-time processing

A comparison of some performance evaluation techniques

In this thesis we look at three approaches to modelling interactive computer systems: Simulation, Operational analysis and Performance-Oriented design. The simulation approach, presented first, is applied to a general purpose, multiprogrammed, machine independent, virtual memory computer system. The model is used to study the effects of different performance parameters upon important performance indices. It is also used to compare or validate the results produced by the other two methods. The major drawback of the simulation model (i.e. its relatively high cost) has been overcome by combining regression techniques with simulation, using simple experimental case studies. Next, operational analysis was reviewed in a hierarchical way (starting by analysing a single-resource queue and ending up by analysing a multi-class customer general interactive system), to study the performance model of general interactive systems. The results of the model were compared with the performance indices produced using the simulation results. The performance-oriented design technique was the third method used for building system performance models. Here, several optimization design problems have been reviewed to minimize the response time or maximize the system throughput subject to a cost constraint. Again, the model results were compared with the simulation results using different cost constraints. We suggest finally, that the above methods should be used together to assist the designer in building computer performance models

Performance of Computer Systems; Proceedings of the 4th International Symposium on Modelling and Performance Evaluation of Computer Systems, Vienna, Austria, February 6-8, 1979

These proceedings are a collection of contributions to computer system performance, selected by the usual refereeing process from papers submitted to the symposium, as well as a few invited papers representing significant novel contributions made during the last year. They represent the thrust and vitality of the subject as well as its capacity to identify important basic problems and major application areas. The main methodological problems appear in the underlying queueing theoretic aspects, in the deterministic analysis of waiting time phenomena, in workload characterization and representation, in the algorithmic aspects of model processing, and in the analysis of measurement data. Major areas for applications are computer architectures, data bases, computer networks, and capacity planning. The international importance of the area of computer system performance was well reflected at the symposium by participants from 19 countries. The mixture of participants was also evident in the institutions which they represented: 35% from universities, 25% from governmental research organizations, but also 30% from industry and 10% from non-research government bodies. This proves that the area is reaching a stage of maturity where it can contribute directly to progress in practical problems

Performance control of internet-based engineering applications.

2006/2007Grazie alle tecnologie capaci di semplificare l'integrazione tra programmi remoti ospitati da differenti organizzazioni, le comunità scientifica ed ingegneristica stanno adottando architetture orientate ai servizi per: aggregare, condividere e distribuire le loro risorse di calcolo, per gestire grandi quantità di dati e per eseguire simulazioni attraverso Internet. I Web Service, per esempio, permettono ad un'organizzazione di esporre, in Internet, le funzionalità dei loro sistemi e di renderle scopribili ed accessibili in un modo controllato. Questo progresso tecnologico può permettere nuove applicazioni anche nell'area dell'ottimizzazione di progetti. Gli attuali sistemi di ottimizzazione di progetti sono di solito confinati all'interno di una singola organizzazione o dipartimento. D'altra parte, i moderni prodotti manifatturieri sono l'assemblaggio di componenti provenienti da diverse organizzazioni. Componendo i servizi delle organizzazioni coinvolte, si può creare un workflow che descrive il modello del prodotto composto. Questo servizio composto puo a sua volta essere usato da un sistema di ottimizzazione inter-organizzazione. I compromessi progettuali che sono implicitamente incorporati per architetture locali, devono essere riconsiderati quando questi sistemi sono messi in opera su scala globale in Internet. Ad esempio: i) la qualità delle connessioni tra i nodi può variare in modo impredicibile; ii) i nodi di terze parti mantengono il pieno controllo delle loro risorse, incluso, per esempio, il diritto di diminuire le risorse in modo temporaneo ed impredicibile. Dal punto di vista del sistema come un'entità unica, si vorrebbero massimizzare le prestazioni, cioè, per esempio, il throughput inteso come numero di progetti candidati valutati per unità di tempo. Dal punto di vista delle organizzazioni partecipanti al workflow si vorrebbe, invece, minimizzare il costo associato ad ogni valutazione. Questo costo può essere un ostacolo all'adozione del paradigma distribuito, perché le organizzazioni partecipanti condividono le loro risorse (cioè CPU, connessioni, larghezza di banda e licenze software) con altre organizzazioni potenzialmente sconosciute. Minimizzare questo costo, mentre si mantengono le prestazioni fornite ai clienti ad un livello accettabile, può essere un potente fattore per incoraggiare le organizzazioni a condividere effettvivamente le proprie risorse. Lo scheduling di istanze di workflows, ovvero stabilire quando e dove eseguire un certo workflow, in un tale ambiente multi-organizzazione, multi-livello e geograficamente disperso, ha un forte impatto sulle prestazioni. Questo lavoro investiga alcuni dei problemi essenziali di prestazioni e di costo legati a questo nuovo scenario. Per risolvere i problemi inviduati, si propone un sistema di controllo dell'accesso adattativo davanti al workflow engine che limita il numero di esecuzioni concorrenti. Questa proposta può essere implementata in modo molto semplice: tratta i servizi come black-box e non richiede alcuna interazione da parte delle organizzazioni partecipanti. La tecnica è stata valutata in un ampio spettro di scenari, attraverso simulazione ad eventi discreti. I risultati sperimentali suggeriscono che questa tecnica può fornire dei significativi benefici garantendo alti livelli di throughput e bassi costi.Thanks to technologies able to simplifying the integration among remote programs hosted by different organizations, engineering and scientific communities are embodying service oriented architectures to aggregate, share and distribute their computing resources to process and manage large data sets, and to execute simulations through Internet. Web Service, for example, allow an organization to expose the functionality of its internal systems on the Internet and to make it discoverable and accessible in a controlled manner. Such a technological advance may enable novel applications also in the area of design optimization. Current design optimization systems are usually confined within the boundary of a single organization or department. Modern engineering products, on the other hand, are assembled out of components developed by several organizations. Composing services from the involved organizations, a model of the composite product can be described by an appropriate workflow. Such composite service can then be used by a inter-organizational design optimization system. The design trade-offs that have been implicitly incorporated within local environments, may have to be reconsidered when deploying these systems on a global scale on the Internet. For example: i) node-to-node links may vary their service quality in an unpredictable manner; ii) third party nodes retains full control over their resources including, e.g., the right to decrease the resource amount temporarily and unpredictably. From the point of view of the system as a whole, one would like to maximize the performance, i.e. throughput the number of candidate design evaluations performed per unit of time. From the point of view of a participant organization, however, one would like to minimize the cost associated with each evaluation. This cost can be an obstacle to the adoption of this distributed paradigm, because organizations participating in the composite service share they resources (e.g. CPU, link bandwidth and software licenses) with other, potentially unknown, organizations. Minimizing such cost while keeping performance delivered to clients at an acceptable level can be a powerful factor for encouraging organizations to indeed share their services. The scheduling of workflow instances in such a multi-organization, multi-tiered and geographically dispersed environment have strong impacts on performance. This work investigates some of the fundamental performance and cost related issues involved in such a novel scenario. We propose an adaptive admission control to be deployed at the workflow engine level that limits the number of concurrent jobs. Our proposal can be implemented very simply: it handles the service as black-boxes, and it does not require any hook from the participating organizations. We evaluated our technique in a broad range of scenarios, by means of discrete event simulation. Experimental results suggest that it can provide significant benefits guaranteeing high level of throughput and low costs.XX Ciclo197

An evaluation of load sharing algorithms for heterogeneous distributed systems

Distributed systems offer the ability to execute a job at other nodes than the originating one. Load sharing algorithms use this ability to distribute work around the system in order to achieve greater efficiency. This is reflected in substantially reduced response times. In the majority of studies the systems on which load sharing has been evaluated have been homogeneous in nature. This thesis considers load sharing in heterogeneous systems, in which the heterogeneity is exhibited in the processing power of the constituent nodes. Existing algorithms are evaluated and improved ones proposed. Most of the performance analysis is done through simulation. A model of diskless workstations communicating and transferring jobs by Remote Procedure Call is used. All assumptions about the overheads of inter-node communication are based upon measurements made on the university networks. The comparison of algorithms identifies those characteristics that offer improved performance in heterogeneous systems. The level of system information required for transfer is investigated and an optimum found. Judicious use of the collected information via algorithm design is shown to account for much of the improvement. However detailed examination of algorithm behaviour compared with that of a 'optimum' load sharing scenario reveals that there are occasions when full use of all the information available is not beneficial. Investigations are carried out on the most promising algorithms to assess their adaptability, scalability and stability under a variety of differing conditions. The standard definitions of load balancing and load sharing are shown not to apply when considering heterogeneous systems. To validate the assumptions in the simulation model a load sharing scenario was implemented on a network of Sun workstations at the University. While the scope of the implementation was somewhat limited by lack of resources, it does demonstrate the relative ease with which the algorithms can be implemented without alteration of the operating system code or modification at the kernel level

A comparative study of the performance of concurrency control algorithms in a centralised database

Abstract unavailable. Please refer to PDF