A survey of general-purpose experiment management tools for distributed systems

International audienceIn the field of large-scale distributed systems, experimentation is particularly difficult. The studied systems are complex, often nondeterministic and unreliable, software is plagued with bugs, whereas the experiment workflows are unclear and hard to reproduce. These obstacles led many independent researchers to design tools to control their experiments, boost productivity and improve quality of scientific results. Despite much research in the domain of distributed systems experiment management, the current fragmentation of efforts asks for a general analysis. We therefore propose to build a framework to uncover missing functionality of these tools, enable meaningful comparisons be-tween them and find recommendations for future improvements and research. The contribution in this paper is twofold. First, we provide an extensive list of features offered by general-purpose experiment management tools dedicated to distributed systems research on real platforms. We then use it to assess existing solutions and compare them, outlining possible future paths for improvements

Integrated scientific workflow management for the Emulab network testbed

Journal ArticleThe main forces that shaped current network testbeds were the needs for realism and scale. Now that several testbeds support large and complex experiments, management of experimentation processes and results has become more difficult and a barrier to high-quality systems research. The popularity of network testbeds means that new tools for managing experiment workflows, addressing the ready-made base of testbed users, can have important and significant impacts. We are now evolving Emulab, our large and popular network testbed, to support experiments that are organized around scientific workflows. This paper summarizes the opportunities in this area, the new approaches we are taking, our implementation in progress, and the challenges in adapting scientific workflow concepts for testbed-based research. With our system, we expect to demonstrate that a network testbed with integrated scientific workflow management can be an important tool to aid research in networking and distributed systems

Data locality in Hadoop

Current market tendencies show the need of storing and processing rapidly growing amounts of data. Therefore, it implies the demand for distributed storage and data processing systems. The Apache Hadoop is an open-source framework for managing such computing clusters in an effective, fault-tolerant way. Dealing with large volumes of data, Hadoop, and its storage system HDFS (Hadoop Distributed File System), face challenges to keep the high efficiency with computing in a reasonable time. The typical Hadoop implementation transfers computation to the data, rather than shipping data across the cluster. Otherwise, moving the big quantities of data through the network could significantly delay data processing tasks. However, while a task is already running, Hadoop favours local data access and chooses blocks from the nearest nodes. Next, the necessary blocks are moved just when they are needed in the given ask. For supporting the Hadoop’s data locality preferences, in this thesis, we propose adding an innovative functionality to its distributed file system (HDFS), that enables moving data blocks on request. In-advance shipping of data makes it possible to forcedly redistribute data between nodes in order to easily adapt it to the given processing tasks. New functionality enables the instructed movement of data blocks within the cluster. Data can be shifted either by user running the proper HDFS shell command or programmatically by other module like an appropriate scheduler. In order to develop such functionality, the detailed analysis of Apache Hadoop source code and its components (specifically HDFS) was conducted. Research resulted in a deep understanding of internal architecture, what made it possible to compare the possible approaches to achieve the desired solution, and develop the chosen one

Leveraging business workflows in distributed systems research for the orchestration of reproducible and scalable experiments

National audienceWhile rapid research on distributed systems is observed, experiments in this field are often difficult to design, describe, conduct and reproduce. By overcoming these difficulties the research could be further stimulated and add more credibility to results in distributed systems research. The key factors responsible for this situation are technical (software bugs and hardware errors), methodological (incorrect practices), as well as social (reluctance to share work). In this paper, the existing approaches for the management of experiments on distributed systems are described and a novel approach using business process management (BPM) is presented to address their shortcomings. Then, the questions arising when such approach is taken, are addressed. We show that it can be a better alternative to the traditional way of performing experiments as it encourages better scientific practices and results in more valuable research and publications. Finally, a plan of our future work is outlined and other applications of this work are discussed.Malgré une activité de recherche sur les systèmes distribués très importante et très active, les expériences dans ce domaine sont souvent difficiles à concevoir, décrire, mener et reproduire. Surmonter ces difficultés pourrait permettre à ce domaine d'être encore plus stimulé, et aux résultats de gagner en crédibilité, à la fois dans le domaine des systèmes distribués. Les facteurs principaux responsables de cette situation sont techniques (bugs logiciels, problèmes matériels), méthodologiques (mauvaises pratiques), et sociaux (réticence à partager son travail). Dans cet article, les approches existantes pour la description et la conduite d'expériences sur les systèmes distribués sont décrites, et une nouvelle approche, utilisant le \textsl{Business Process Management (BPM)}, est présentée pour répondre à leurs limitations. Puis diverses questions se posant lors de l'utilisation d'une telle approche sont discutées. Nous montrons que cette approche peut être une meilleure alternative à la manière traditionnelle de conduire des expériences, qui encourage de meilleures pratiques scientifiques, et qui résulte en une recherche et des publications de meilleure qualité. Pour finir, notre plan de travail est décrit, et des applications possibles de ce travail dans d'autres domaines sont décrites

Using business workflows to improve quality of experiments in distributed systems research

International audienceDistributed systems pose many difficult problems to researchers. Due to their large-scale complexity, their numerous constituents (e.g., computing nodes, network links) tend to fail in unpredictable ways. This particular fragility of experiment execution threatens reproducibility, often considered to be a foundation of experimental science. Our poster presents a new approach to description and execution of experiments involving large-scale computer installations. The main idea consists in describing the experiment as workflow and using achievements of Business Workflow Management to reliably and efficiently execute it. Moreover, to facilitate the design process, the framework provides abstractions that hide unnecessary complexity from the user

Industrial Design in Aerospace/Role of Aesthetics

Industrial design creates and develops concepts and specifications that seek to simultaneously and synergistically optimize function, production, value and appearance. The inclusion of appearance, or esthetics, as a major design metric represents both an augmentation of conventional engineering design and an intersection with artistic endeavor(s). Report surveys past and current industrial design practices and examples across aerospace including aircraft and spacecraft, both exterior and interior

Orchestration d'expériences à l'aide de processus métier

National audienceLa recherche sur les systèmes distribués a quelques caractéristiques qui la rende intéressante, difficile et unique. D'abord, les systèmes modernes sont souvent trop compliqués pour permettre une analyse formelle et théorique. Ainsi, l'approche la plus courante est l'analyse empirique, par exemple à l'aide d'expériences. Malheureusement, à cause de la complexité des systèmes informatiques, réaliser des expériences est très difficile à faire correctement, avec une rigueur scientifique suffisante et de façon reproductible. Cet article présente une idée novatrice pour écrire, représenter et conduire les expériences scientifiques impliquant une multitude des noeuds hétérogènes connectés par un réseau. L'idée centrale consiste à utiliser la modélisation et le pilotage de processus métier (Business Process Modeling et Business Process Management). Notre solution a de nombreux avantages, dont les plus importants sont la facilité d'écrire et de comprendre une description d'expérience, et la robustesse d'exécution d'expériences même en présence de problèmes de traitement. Après la présentation de notre approche, un prototype du moteur de conduite d'expériences est validé à l'aide d'un cas d'utilisation de référence

3rd EGEE User Forum

We have organized this book in a sequence of chapters, each chapter associated with an application or technical theme introduced by an overview of the contents, and a summary of the main conclusions coming from the Forum for the chapter topic. The first chapter gathers all the plenary session keynote addresses, and following this there is a sequence of chapters covering the application flavoured sessions. These are followed by chapters with the flavour of Computer Science and Grid Technology. The final chapter covers the important number of practical demonstrations and posters exhibited at the Forum. Much of the work presented has a direct link to specific areas of Science, and so we have created a Science Index, presented below. In addition, at the end of this book, we provide a complete list of the institutes and countries involved in the User Forum

Towards Complete Tracking of Provenance in Experimental Distributed Systems Research

International audienceRunning experiments on modern systems like supercomput-ers, cloud infrastructures or P2P networks became very complex, both technically and methodologically. It is difficult to rerun an experiment or understand its results even with technical background on the technology and methods used. Storing the provenance of experimental data, i.e., storing information about how the results were produced, proved to be a powerful tool to address similar problems in computational natural sciences. In this paper, we (1) survey provenance collection in various domains of computer science, (2) introduce a new classification of prove-nance types, and (3) sketch a design of a provenance system inspired by this classification

Interaction Tangible sur Table, définitions et modèles

International audienceIn recent years, tangible user interfaces, which imply interactions performed with one or several objects, gain more and more interest in research in Human-Computer Interaction (HCI). The tangible object represents a subject or an action. It acts on the system, as an action in classical user interfaces (e.g,. GUI). Interaction on a table, which is a common furniture in everyday life and used in multiple activities (desktop, coffee table, kitchen table, etc.), opens a new way for research and development in HCI. In this article, we present definitions, models, and key issues elicited from the literature that enable understanding and reasoning about the couple within an interactive system. Then, we propose a framework that allows to characterize applications supported by the couple in a domain-independent manner.Depuis quelques années les interfaces tangibles impliquant des interactions réalisées via un objet (ou plusieurs) prennent de plus en plus d’importance dans les recherches en interaction homme-machine. L’objet tangible représente un sujet ou une action ; l’objet agit sur le système, telle une action sur une interface « classique ». L’interaction sur table, c’est-à-dire sur un meuble présent dans la vie courante et utilisé à diverses fins (bureau, table à manger, table de salon, table bar, etc.), ouvre un champ nouveau de recherche et de développement. La mise en exergue, issue de l’état de l’art, des définitions, modèles et problématiques, permet d’abord d’appréhender le couple (table, objet tangible) au sein d’un système interactif. Puis, nous proposons un cadre qui permet de positionner des applications mettant en oeuvre le couple (table, objet tangible). Le cadre est décrit de manière à être utilisé pour positionner des applications indépendamment du domaine